JOHN DEERE 7520 TRACTOR Service Repair Manual Instant Download

1
TECHNICAL MANUAL
2
7520 TRACTOR TECHNICAL MANUAL TM-1053 (Jan-72)
CONTENTS SECTION 10 - GENERAL Group 5 - Genera
Tractor Specifications Group 10 - Predelivery,
Delivery, and After-Sale Services Group 15 -
Tune-Up Group 20 - Lubrication Group 25 -
Separation Group 30 Torques and Special
Tools SECTION 20 - ENG INE Group 5 - General
Information, Diagnosis, and Tests Group 10 -
Cylinder Head, Valve Train, and Cam- shaft Group
15 - Cylinder Block, Liners, Pistons, and
Rods Group 20 - Crankshaft, Main Bearings, ând
Fly- wheel Group 25 - Lubrication System Group 30
- Cooling System Group 35 - Specifications SECTION
30 - FUEL SYSTEM Group 5 - Diagnosing
Malfunctions Group 10 - Air Intake System
SECTION 50 - POWER TRAIN Group 5 - Clutch Group
10 - Torque Divider
Group 15 Syncro-Range Transmission Group 20 -
Differentials Group 25 - Final Drives Group 30 -
PTO Group 35 - Specifications SECTION 60 -
STEERING AND BRAKES croup 5 - General Information
SECTION 70 - HY DRAULIC SYSTEM Group 5 - General
Information, Diagnosis, and TestS Group 10 - Main
Reservoir, Filters, Valves, Oil Cooler, and Oil
Reservoir Group 15 - Hydraulic Pumps Group 20 -
Power Steering Group 25 - Power Brakes Group 30 -
Selective Control Valve, Breakaway Couplers, and
Remote Cylinders Group 35 - Specifications
SECTION 80 - MI SCELLANEOUS Group S Hinge
Assembly
Group 15 Fuel Injection System Group 20 - Speed
Control Adjustment Group 25 - Specifications SECTI
ON 40 - ELECTRICAL SYSTEM
Group 5 Group 10
Information and Wiring Diagrams Motorola Charging
Circuit
Group 15 - Delcotron Charging Circuit Group 20 -
Starting Circuit Group 25 - Lighting and
Accessory Circuits Group 30 - Specifications
AII information, illustrations and specifications
con- tained in this technical manual are based on
the latest information available at the time of
publication. The right is reserved to make
changes at any time without notice. Copyrights
1872 DEERE COMPANY Mollne, Illinois All rights
reserved
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Tractor - 7520 TM-1053 (Jan-72)
INTRODUCTION
Use FOS Manuals for Reference
Use Technical Manuals for Actual Service
This technical manual is part of a twin concept
of ser- vice
Some features of this technical manual

• Table ol contents at lront of manual

• FOS Manualsfor reference

• Exploded views showing parts relationship

• Technical Manualsfor actual service

• Photos showing service techniques

The two kinds of manuals work as a team to give
you both the general background and technical
details of shop service.

• Specifications grouped lor easy reference

This technical manual was planned and written for
youa journeyman mechanic. Keep it in a perma-
nent binder in the shop where it is handy. Refer
to it whenever in doubt about correct service
procedures or specifications.
Fundamentals of Service (FOS) Manuals cover basic
theory of operation, fundamentals of trouble
shooting, general maintenance, and basic types of
failures and their causes. FOS Manuals are for
training new men and for reference by experienced
men.
Technical Manuals are concise service guides for
a specific machine. Technical Manuals are
on-the-job guides containing only the vital
information needed by a journeyman mechanic.
Using the technical manual as a guide will reduce
error and costly delay. It will also assure you
the best in finished service work.
This safety alert symbol identifies important
safety messages in this manual. When you see this
symbol, be alert to the possibility of personal
inju- ry and carefully read the message that
follows.

• When a serviceman should refer to a FOS Manual
  for more information, a FOS sym-
• bol like the one at the left is used in the TM
  to identify the reference.

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Tractor - 7520 TM-1053 (Jan-73)
Gezie/a/ 10 Specifications 5-1
Section 10 GENERAL
CONTENTS OF THIS SECTION
GROUP 5 - GENERAL TRACTOR SPECI
FICATIONS 5-1 GROUP 10 - PREDELI VERY, DELI
VERY, AND AFTER-SALE SERVICES Predelivery
Services .................... 10-1 Delivery
Services ...................... 10-3 After-Sale
Services ..................... 10-4
GROUP 25 - SEPARATION Removing Roll-Gard Cab
Installing Roll-Gard Cab Separating Engine from
Clutch
25-1 . 25-2
Housing ............................
25-2 Separating Engine from Tractor Front End
.......................... 25-4 Removing Engine
...................... 25-6 Removing Front Axle
Assembly ........... 25-7 Separating Transmission
and Differential from Torque Divider 25-9
Separating Torque Divider and Tractor Rear End
from Hinge .......... 25-10 Separating Clutch
Housing
GROUP 15 - TUNE-UP Preliminary Engine Testing
............... 15-1 Engine Tune-Up
....................... 15-1 Engine Final Testing
.................... 15-3 Tray.tor Tune-Up
....................... 15-3
from Front Hinge ...... .. . 25-11 Removing Final
Drive Assembly .......... 25-12
GROUP 20 - LUBRICATI ON Lubrication Chart
...................... 20-1
Engine Lubricating Oils .... .. . 20-2
Transmission-Hydraulic Oil .............. 20-2
Group 30 - SPECIFICATIONS AND SPECI AL
TOOLS Specifications .........................
30-1 Special Tools .......................... 30-2
Greases ..............................
20-2 Storing Lubricants ......................
20-2
Group 5 GENERAL TRACTOR SPECIFICATIONS LUBRICATION
SYSTEM ........ Force-feed pres-
HORSEPOWER
surized with full-flow oil filter
Maximum observed at PTO ............... 175.82
Fuel System Type ....................... Direct
injection Injection pump type .......... Multiple
plunger, in-line Air cleaner .....................
... Dry type with safety element
ENGINE Type ......... 6-cylinder, in-line,
valve-in-head, diesel, turbocharged, and
intercooled
Engine Speeds
Slow idle .. . . ............... 800 rpm
Working range ............ 1500 to 2100 rpm
Maximum transport speed ......... 2300 rpm
Cooling System Type ........ Pressurized with
centrifugal pump Temperature control ... 3
heavy-duty thermostats
Bore and stroke ............... 4-3/4 in. x 5
in. Displacement .................... 531 cu. in.
Compression ratio ... .. . .. . 15.4 to 1
Capacities Fuel tank ...................... 78
U.S. gals. each tank Crankcase (with filter
change) ...... 26 U.S. qts. Transmission-hydraulic
system .... 19 U.S. gals. Cooling system
.................. 40 U.S. qts. Front
differential ................. 7 U.S. gals.
Firing order ..................... 1-5-3-6-2-4
Valve clearance ................. In.-0.018
in. Ex.-0.028 in.
Injection pump timing . . official tast at
2100 engine rpm.
27 BTDC
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s 0 General 5-2 SpecificatiofiS
tractor - 7520 TM-1053 (Jan-73)
Power Take-Off Type ...................
Transmission-driven Speed 1800 engine rpm in Hi"
........... 1000 rpm 2100 engine rpm in Lo" or
with standard 8-speed transmission ..... 1000 rpm
PTO ahead of drawbar hitch point ........ 20 in.
Transmission Type ........... Syncro-Range,
constant mesh Clutch ............. Heavy-duty,
13-1/2 in. dual plate, hydraulic assist, foot
operated Gear selections ......... 8 forward and
2 reverse Shifting ... Two lever shifting,
synchronized shift- ing within stations, except
reverse gears Optional "Hi-Lo" speed selec- tor
provides two speeds in each gear for 16 forward
and 4 reverse.
Hydraulic System
Type
. Closed center, constant pressure. In- cludes
power steering, power brakes,
implement control, and transmission
and differential lubrication
Ground Speeds (in miles per hour, 2100 engine rpm)
Standby pressure ........ . 2250 psi Brakes
............. Hydraulically powar-actuated disk-ty
pe operating in oil Tires ...............
23.1-30, 8-ply rating
2.39 3.82 5.04 6.48 8.07 10.58 13.70 22.35
1st .....................
2.08 3.33 4.39 5.64 7.02 9.20
2nd ....... ....... ..
3rd ..... ...............
4th . ...... ...
Wheel Tread ......
See operator's manual
Sth .....................
6th . .. .........
Dimensions Wheel base .......................
125 in.
7th ..................... 11.91
8th ..................... 19.44
Over-all Iângth .over-all height
.................... 220 in. ....................
123 in. -With air conditioner 131 in.
4.27 6.84
4.91 7.86
1st reverse 2nd
Over-all width ..................... 95-7/8
in. -long-axle-114 in. Turning radius (80-in.
tread) 220 in. Shipping Weight (With equipment
for average field service, less fuel and ballast)
.... 16,790 lbs.
Electrical System Type .............. 12-volt,
negative grounded Batteries ..... Two, 6-volt,
87-plate, 204-ampere- hour, 7D type, connected in
series Alternator ........ 12-volt, with
translstorlzed regulator 55 amp without air
conditioning 72 amp with air conditioning
Additional tlre 5Ize5 avai/abfe
' Grow/nd speeds for tractors 'Ith standard
8-speed transmission are the same as
Lo. (Specifications and design cublect to
change without not/ce.)
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Tractor - 7520 TM-1053 Jan-73/
Genera/ 10 Predelivery, Delivery, and After-Sale
Services 10-1
Group 10 PREDELIVERY, DELIVERY AND
AFTER-SALE SERVICE PREDELIVERY SERVICE
Because of the shipping factors involved, plus
ex- tra finishing touches that are necessary. to
promote customer satisfaction, proper predelivery
service is of prime importance to the dealer. A
tag pointing out the factory-recommended pro-
cedure for predelivery service is attached to
each new tractor before it leaves the factory.
After completing the factory-recommended dealer
checks and services listed on the predelivery
tag, remove the tag from the tractor and file it
with th e shop order for the job. The tag will
certify that th e tractor has received the proper
predelivery service when the portion of the
customer's John Deere Deliv- ery Receipt is
completed.
NOTE A Caplug is placed in the muffles outlet to
prevent turbocharger rotation during transit.
Remove Cap- lug before unloading tractor.
Reinstall Caplug before transporting the tractor
to the customer. Temporary Tractor Storage
Specnkatlon Reference
Check radiator for coolant loss and antifreeze protection Reduce shipping pressure of tires Cover tractor and tires for protec- tion and cleanliness Within 3/4-in. from bottom of filler neck. Operator's manual
Before Delivering Tractor
ELECTRICAL SYSTEM
Install electrolyte and charge batteries Date code battery warranty tag Connect Motorola alternator. Do not attempt to polarize Install light switch knob Clean terminals and connect battery cables . Check alternator belt adjustment COOLING SYSTEM Inspect radiator for coolant loss Chec k antifreeze protection FOS - 20 Manual
Install electrolyte and charge batteries Date code battery warranty tag Connect Motorola alternator. Do not attempt to polarize Install light switch knob Clean terminals and connect battery cables . Check alternator belt adjustment COOLING SYSTEM Inspect radiator for coolant loss Chec k antifreeze protection FOS - 20 Manual
Install electrolyte and charge batteries Date code battery warranty tag Connect Motorola alternator. Do not attempt to polarize Install light switch knob Clean terminals and connect battery cables . Check alternator belt adjustment COOLING SYSTEM Inspect radiator for coolant loss Chec k antifreeze protection Section 40, Group 10
Install electrolyte and charge batteries Date code battery warranty tag Connect Motorola alternator. Do not attempt to polarize Install light switch knob Clean terminals and connect battery cables . Check alternator belt adjustment COOLING SYSTEM Inspect radiator for coolant loss Chec k antifreeze protection Section 40, Group 5
Install electrolyte and charge batteries Date code battery warranty tag Connect Motorola alternator. Do not attempt to polarize Install light switch knob Clean terminals and connect battery cables . Check alternator belt adjustment COOLING SYSTEM Inspect radiator for coolant loss Chec k antifreeze protection 1-inch deflection, 25 lb. force. Operator's manual
Install electrolyte and charge batteries Date code battery warranty tag Connect Motorola alternator. Do not attempt to polarize Install light switch knob Clean terminals and connect battery cables . Check alternator belt adjustment COOLING SYSTEM Inspect radiator for coolant loss Chec k antifreeze protection Within 3/4-in. from bottom of filler neck.
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10 General
Tractor
7520
Predelivery, Delivery, and Affer-Sa/e Services
TM-1053
(Jan-73)
10-
Before Delivering TractorContinued
Reference
TIRES AND WHEELS Adjust pressure of tires Check wheel rim clamp nuts, and wheel retainer cap screws for tightness . . Set front and rear wheel tread to a minimum of 80 in., and add at least 1,000 lb. ballast to each wheel for single whe.eI operation .. . Hillside operationuse double wheels only . . LUBRICATION Check crankcase oil level Check transmission-hydraulic sys- tem oil level Check front differential oil level Lubricate grease fittings . ENGI NE Check air cleaner ....... Fill fuel tank and start engine ...... Check operation of starter, alterna- tor, flasher, gauges, and indicator lights Check engine timing . . Check engine speeds . . Retainer cap screws-300 ft-lbs Rim clamp nuts-170 ft-lbs ....... To upper marks on dipstick To top of SAFE" range on dipstick. Type 303 Special- Purpose Oil To level of filler plug opening. Type 303 Special-Purpose Oil. John Deere Multipurpose Lubricant Capacity - 78 U.S. gallons each tank . 27 BTDC 800 rpm, slow idle speed 2300 rpm fast idle speed and max. transport speed Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Section 30, Group 15 Section 30, Group 15
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nactor - 75P0 7M-1058 (Jan-72) Before
Delivering TractorContinued
Generel \ 0 Predelivery, Oe/ivery, and A
fler-Sa/e Services \ 0-3
Sewllte
OPERATION Check transmission clutch free travel Shift transmission through all Speeds . Check throttle linkage for free operation. Adjust headlights and check operation Check power takeoff operation Check brakes and accumulator . Check air conditioning, heater, and pressurizer operation. ........ Check hydraulic system operation steering, rockshaft, and remote cylinder Check seat operation .... GENERAL Tighten accessible nuts and cap Clean tractor and touch up paint Approximately 1-11/16 inches free travel (engine at tast idle) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 in. maximum travel when brakes have been bled, and accumulator is working properly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operator's manual Operator's manual Section 30, Group 20 Operators manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual
DELIVERY SERVICE
A thorough discussion of the operation and
service of a new tractor at the time of delivery
helps to assure co mplete customer satisfaction.
Proper delivery should be an important phase of a
dealer's program. A par tion of the John Dears
Dalivary Racaipt am - phasizes the importance of
proper delivery service. Many complaints have
arisen simply because the owner was not shown how
to operate and service his new tractor properly.
Spend enough time, at the cus- tomer's
convenience. to introduce the owner to his new
tractor and explain to him how to operate and
service it properly. I MPORTA NT l ngtall Caplug
In WUffle OUt 4 transporting tractor to
customer. This will prevent damage to the
turbocharger caugcd by alr passing through the
turbocharger and rotating It whhou usi. cation
when the engine lv Authea.

• The following procedure is recommended before the
  serviceman and owner compl ete the deliver y
  acknowledgments portion of the delivery receipt.
• Using the tractor operator's manual as a guide,
  be sura that the owner understands thase points
  thor- oughly
• Controls and instruments.
• How to start and stop the engine.
• 3 The importance of the break-in period.
• 4. How to use liquid or cast-iron ballast.
• /. All functions of the hydraulic system.
• Using the power takeoff.
• The importance of safety.
• The importance of lubrication and periodic ser-
  vlces

After explaining and demonstrating the above fea-
tures, have the owner sign the delivery receipt
and give him the operators manual.
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10 Genera/ 10-4 Predelivery, Delivery, and
After-Sale Services
7520
Tractor TM-1053 (Jan-72)
AFTER-SALE INSPECTION
The purchaser of a new John Deere tractor is
enti- tied to a free inspection within the
warranty period after the equipment has been run
in." The terms of this after-sale inspection are
outlined on the back of the John Deere Delivery
Receipt. The purpose of this inspection is to
make sure that the customer is receiving
satisfactory performance from his tractor. At the
same time, the inspection should reveal whether
or not the tractor is being oper- ated,
lubricated, and serviced properly.
If the recommended after-sale service inspection
is followed, the dealer can eliminate a needless
vol- ume of service work by preventing minor
irregulari- ties from developing into serious
problems later on. This will promote strong
dealer-customer relations and present the dealer
an opportunity to answer questions that may have
arisen during the first few days of operation.
During the inspection service, the dealer has the
further opportunity of promoting the possible
sale of other new equipment. The following
inspection program is recommended within the
first 100 hours of tractor operation.
Inspection Procedure
Sarvlce Spacfflcatlon Reference
COOLI NG SYSTEM Check radiator coolant level Clean external surface of radiator core Check hoses and connections for leaks FUEL SYSTEM Remove water and foreign matter from filter sediment bowl Bleed fuel system . Tighten loose connections and check entire system for leaks, correct if necessary ... Check air cleaner element, and unloading valve. Clean element if necessary . ELECTRICAL SYSTEM Check specific gravity of batteries ... Check level of battery electrolyte .... Check belt tension Within 3/4-in. from bottom of filler neck. Full charge - 1.260 at 80F. To bottom of filler neck in each cell 1-inch deflection with a 25- pound force Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual Operator's manual
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Tractor - 7520 TM- 1053 (Jan-72) Inspection
ProcedureContinued
General 10 Predelivary, Oe//very, and After-Sale
Services 4 g-5

Start engine and check operation ot Starter, lights, and indicator lamps LUBRICATION Check crankcase oil level Chec k transmission-hydraulic system oil level . Check front differential oil level ENG I NE Check valve clearance Check engine speed under load, fuel consumption, and horsepower TRACTOR A ND POWER TRAI N Check transmission clutch free travel Shift transmission through all speeds Check power steering Check brakes and accumulator . To upper marks on dipstick In SAFE" range on dipstick. Use John Deere Type 303 Spec ial-Purpose Oil To level with filler plug opening Use John Deere Type 303 Special-Purpose Oil Intake 0.018-inch Exhaust 0.028-inch Specification Approximately 1-11/16 inches free travel (engine at fast idle) . . . . . . . . . . . . . . . . . . . . . . . . . Smooth, easy operation 3 inches maximum brake travel when brakes have been bled and accumulator is working properly. Operator's manual Operators manual Operator's manual Operator's manual Operator's manual Group 15 of this Section. Operator's manual Operator's manual Section 70, Group 20 Operator's manual
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Tractor - 7520 TM-1053 (Jan-72)
10 General 10-6 Predelivery, Delivery, and
After-Sa/e Servlces
Inspection ProcedureContinued
Service Specification
HYDRAULIC SYSTEM Check rockshaft and remote cylin- der operation Reverse signal lockout ..... ... .. Check entire tractor for leaks. lnspect drive shafts, hydraulic system pipes and hoses, and check tractor cab controls for proper operation NUTS AND CAP SCREWS Tighten accessible nuts and cap screws that seem to require ad- justment . Section 70, Group 30 Section 70, Group 30 Operator's manual
TORQUE CHART (ft-lbs)
Bolt Diameter Rain Head Three Radial Daehca Sts Radial DaeMs
1/4 6 10 14
5/16 13 20 30
3/8 23 35 50
7/16 35 55 80
1/2 55 85 120
9/16 75 130 175
5/8 105 170 240
3/4 185 300 425
7/8 160 445 685
1 250 670 1030
The types of bolts and cap screws are identified
by head markings as follo'ws Plain Head
regular machine bolts and cap screws. 3-Dash
Head tempered steel high-strength bolts and cap
screws. 6-Dash Head tempered steel extra
high-strength bolts and cap screws. Machine bolts
and cap screws 7/8-inch and larger are somtimes
formed hot rath er than cold, which accounts for
the lower torque.
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Tractor - 7520 TM-1053 flan-73/
General 10 Tune-0p s-
Group 15 TUNE-UP tion is satisfactory, proceed
with the tune-up. Choose from the following
procedures only those necessary to restore the
unit.
Before tuning up a tractor, determine whether a
tune-up will restore operating efficiency. When
there is doubt, the following preliminary tests
will help to determine if the engine can be tuned
up. I f the condi- Preliminary Engine Testing
Operation
Dynamometer Test Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator
(at 2100 engine rpm full load) Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator
Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator FOS - 30 Manual, Chapter 12
Compression Test . Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator FOS - 30 Manual,
Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator Chapter 12
Engine Coolant Check Test Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator
Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator FOS - 30 Manual,
Compare with previous recorded output compare with output after tune-up 330-380 at 200-250 rpm . . No air bubbles or oil film in radiator Chapter 12
I
Engine Tune-up
Operation Specification
Air Intake System Service air cleaner and check system for leaks Check system for restrictions using water manometer Normal reading, inches of water (with clean filter elements) Maximum permitted reading Check restriction indicator light operation Exhaust System Check system for leaks . Check muffler and exhaust pipe for restrictions 16 in. at 2100 rpm (full load) 25 in. at 2100 rpm (full load) 24-26 in. at 2100 rpm (full load) FOS - 30 Manual, Chapter 12 FOS - 30 Manual, Chapter 12 FOS - 30 Manual, Chapter 12 FOS - 30 Manual, Chapter 12
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10 General 15-2 Tune-up
tractor
7520
TM- 1053
(Jan-73)
Engine Tune-upContinued Engine Tune-upContinued Engine Tune-upContinued
Operation SectionGroup
Crankcase Ventilating System Check system for restrictions . . Cooling System Clean grill screen, radiator core, and oil cooler core Clean and flush system check thermostat Check pressure cap Cylinder Head and Valves Torque cylinder head cap screws Set valve clearance ........... Diesel Fuel System Check fuel tank for water ...... Check fuel pump pressure . . .. Change filter Injection Pump Service and check timing ... ... Adjust throttle linkage Lubrication system Check engine oil pressure .. . . Charging System Check battery specific gravity Check battery water consump- tion and electrolyte level ... Clean battery, cables, and box . . , Check alternator belt tension .... Check alternator output ..... Gheck alternator regulated voltage . . . . . . . . . . . . . . . . . . . . . 6.25 to 7.50 psi release pressure 180 ft-lbs. in sequence Intake 0.018-in. Exhaust 0.028-in. Approx. 20 psi . .. .. .. .... 27 BTDC ............. 2300 rpm fast idle speed (hand throttle and foot throttle) . 800 rpm slow idle speed ............ 40 - 50 psi (2100 rpm) 1.240 1.260 25 lbs. at 1-in. belt deflection 50 amps (2000 engine rpm). On air conditioned tractors, 65 amps (2000 engine rpm) 14.1 - 14.7 volts operating) .. . . FOS - 30 Manual, Chapter 12 20-30 20-30 20-30 20-10 20-10 30-15 30-15 30-15 30-15 30-20 30-20 20-25 40-10 40-10 40-10 40-10 40-10 40-10
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Tractor - 7520 TM-1053 (Jan-73)
General 10 Tune-Up 15-3
engine Tune-upContinued
Semlon-Group Reference
Operasi
Starting System Check start-safety
switch operation Check battery voltage
when starting Check starter current draw Check
operation of alternator and oil pressure
indicator lights
40-15
Min. 9 volts (cranking) Approx. 525 amps . .
40-15 40-15
40-25
Final Engine Test
Operation Section-Group
Dynamometer Test (at 2100 engine rpm) Compare with previous recorded output record for future use ... FOS - 30 Manual - ENGI NES, Chapter 12
Tractor Tune-up
Operation Speclflcatlon Sacclon-Group Reference
Adjust transmission clutch free travel Transmission Check shifting . Check for proper operation without excessive noise Power Take-Off Check for proper operation without excessive noise . .. Check brake pedal travel and even position Check tire inflation ..... Transmission pump Main hydraulic pump Pressure control valve Selective control valve . 1-11/16-in. (engine at fast idle) 3-inch maximum travel with brakes bled and with accumulator working properly See operator's manual 9 gpm at 1900 rpm (in Lo or with 8-speed transmission) Standby - 2200 - 2300 psi Capacity - 21 gpm (2000 psi and 1800 rpm) 1650 - 1700 psi at 800 rpm (approxi- mately 5 gpm flow) 2 to 20 gpm at 1200 psi and 1900 rpm .... .. 50-5 50-10 15 50-15 50-30 70-25 70-5 70-5 70-5 70-5
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Tractor
7520
10 General 15-4 Tune-Up
TM-1053
(Jan-73)
Tractor Tune-upContinued
Operation Operation Spacfflcatlon Section-Group Reference
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout 2.4 - 2.7 seconds at 1900 rpm 70-5
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout 12.5 gpm at 2000 psi and
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout 1900 rpm . 70-5
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout Complete raise with lever rear edge
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout 1/32- to 1/16-inch from rear of slot . 70-30
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout Begins to raise when rear edge of lever
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout is at O" on quadrant ... 70-30
Rockshaft Lift cycle time (75 degrees rotation) . . Maximum oil flow Lever position (depth control) Lever position (load control) Reverse signal lockout 70-30
Hydraulic system pressures, llo ' rates, or cycle
times are lor condltions specified in Section 70
(tractor and transmission-hydraulic oil at
operating temperature, proper test equipment,
correct test sequence, etc.).
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Tractor - 7520 TM-1053 Jan-73)
General 10 Lubrication 20-1
Group 20 LUBRICATION GENERAL INFORMATION
Carefully wi itten and illustrated instructions
are included in the tractor operator's manual.
Remind your c usto mer to follow the
recommendations in these instructions.
For your convenience when servicing the tractor,
the following chart showing capacities and type
of lubricant for the various components has been
includ- ed. Additional lubrication information is
on page 20-2.
Component Capacky Yype of Lubricant Interval of Service
Engine Crankcase 26 U.S. quarts See "Engine Lubricat- 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
(Includes filter) ing Oils" on page 20-2 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
Transmission and 22 U.S. gallons John Deere Type 303 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
Hydraulic system (dry system) Special-Purpose Oil 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
19 U.S. gallons at 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
service intervals 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
Front differential 7 U.S. gallons Joh n Deere Type 303 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
Special-Purpose Oil 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
Grease Fittings John Deere Multi- 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
purpose Lubricant 10 Hours - Check level 100 Hours - Change oil 200 Hours - Replace filter 200 Hours - Check level 600 Hours - Replace filter 1200 Hours - Change oil 1200 Hours - Change oil See Operator's Manual
I
Litho in U.S.A.
18
10 General 20-2 Lubrication
Tractor
7520
TM-1053
(Jan-73)

LUBRICANTS
Engine Lubricating Oils
Depending on the expected prevailing temperature
for the fill period, use oil of viscosity as
shown in the following chart.
Other Oils
Air Temperature John Deere Torq-Gard Oil Single Vis- coslty Oh Multi-Vis- coslty Oil
Above 32F. SAE 30 SAE 30 Not recom- mended
10F. to 32F. SAE 10W-20 SAE 10W SAE 10W-30
Below 10 F. SAE 5W-20 SAE 5W SAE 5W-20
We recommend John Deere Torq-Gard or Torq- Gard
Supreme Engine Oil for use in the engine crank-
case. These oils are compounded specifically for
use in John Deere engines and provide superior
lubrica- tion under all conditions. NEVER PUT
ADDITIV ES IN THE CRANKCASE. Torq-Gard oils are
formulated to provide all the protection this
engine needs. Additives could reduce this
protection rather than help it.
SAE 5 W-20 oil may be used where required to
insure optimum lubrication at starling,
particularly /or an engine subjected to 10 F.
or lo wer lor several hours.
I f Torq-Gard or Torq-Gard Supreme is not used,
use an engine oil that conforms to one of the
following specifications
Some increase in oi/ consUmpfion may be expect-
ed when SAE 5W-20 or SAE 5 W oils are used. Check
oil level more frequently.
SINGLE V ISCOSITY OILS
API Service CD/SD MIL-L-2104C Series 3
Transmission Hydraulic Oils Use only John Deere
Type 303 Special-Purpose Oil or its equivalent in
the transmission-hydraulic system. Other types of
oil will not give satisfactory service, and may
result in eventual damage. This special oil may
be used in all weather conditions.
MULTI-VISCOSITY OILS
API Service CC/SE, CC/SD, or SD MI L-L-46152
Greases John Deere Multi-Purpose Lubricant or an
equiva- lent SAE Multipurpose-Type grease is
recommended for grease fittings. Application of
grease as instructed in the lubrication section
of the operator's manual will provide proper
lubrication and will keep contamina- tion out of
bearings.
As further assurance ol quality, the oil
should also be identified as suitable /or API
service designation SD.
Storing Lubricants A tractor can operate at top
efficiency only if clean lubricants are used. Use
clean containers to handle all lubricants. Store
them in an area protected from dust, moisture,
and other contamination.
Litho in U.S.A.
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General 10 Separation 25-1
tractor - 7520 FM- 1053 (Jan -73)
Group 25 SEPARATION
CAUTION Before separating tractor, be sure j_at_
that the brake accumulator is discharged. The
accumulator can be discharged by opening the
rigM- hand brake bleed screw, and holding the
brake pedal down tar a few minutes. DO not work
around hlnge with the engine running.
REMOVING ROLL-GARD CAB The Roll-Gard cab is
bolted to special brackets that are fastened to
the front hinge and side frames. To facilitate
the removal of the Roll-Gard cab, turn the
tractor to either the extreme left or right turn
posi-
Fig. 2-seater Hoses
tion, loosen the Roll-Gar d attaching bol ts, and
then
tur n to th e oth er extreme pos it ion , and
loos en the bolts (fig. 4). CAUTION To prevent
possible Injury, do not work around the hinge
with the engine running. Always be sure that the
engine is stopped, and that no one is In cab
before proceeding wfth the removal. Drain the
cooling system. Remove the muffler, ver- tical
air stack, side grille screens, cowl, cab center
pane1,and hood
Fig. 3-Compressor Mounting
3. Loosen the compressor drive belt and remove
the compressor mounting bolt (Fig. 3). Remove
com- pressor (with refrigerant hoses connected
to com- pressor) , and place unit inside cab or
tasten to cab. Do not disconnect the refrigerant
hoses unless abso- Iutely necessary.
CAUTION H'henever the refrigerant hoses are to
be disconnected, first discharge the com- pressor
or the complete system as explained in SM- 2089
(Tractor Air Conditioning and Heating Systems)
under DISCHARG I NG THE SYSTEM. Follow all satety
precautions listed in the manual to avoid
personal in- jury. Disconnect hydraulic hoses
fro m breakaway cou- plers, roc kshaft, and
selective control valve manifold (p r es sur e
and ret urn) on t rac to rs w i th ro c k shaft.
Re mo ve th e c ab fl oor m at, and th e n ec
essary ca b panels to allow cab to clear the
control support hous- ing and seat. Fasten cab
lifting bracket (Group 30, Fig. 2) to the lifting
straps on cab roof and attach to an overhead
hoist.
Fig. 1-Cab Wiring Connections

1. Disconnect cab wiring from connectors and cir-
   cuit breakers (Fig. 1) . Remove wiring harness
   from clamps and lay wiring inside cab. Disconnect
   wiring from dimmer switch.
2. Disconnect heater pressure and return hoses (Fig.
   2) .

L/fno in U.S.A.
20
10 General 25-2 Separation
Fig. 4- Roll-Gard a xc Ca b Mo unt in g
Bolds Remove Roll-Gard and cab mounti ng bolts
(Fig. 4) . Be sure that all hoses and wiring are
disconnected from tractor. Lift off cab.
I NSTALLI NG ROLL-GARD CAB Reverse the removal
steps. Torque Roll-Gard bolts to 670 ft-Ibs. The
centerline of cab should lire up with the cen- te
rl i n e of tr a cto r. Th e fo am r u bber s eal
o n cen te r cowl pa net oI c a d sh oul d be e q
u a I! y compres se d around the contour of hood.
Shift cab as required to align correctly. After
the cab panels and extensions are in place, seal
all holes and openings with tape, foam material,
or sealant before installing floor mat. Careful
sealing ot all openings must be done for the
pressurizer to be effective in keeping out dust
and dirt. Install floor mat. Instell air
conditioning compres- sor (if equipped) , and
adjust the drive belt to 1/4-inch deflection with
a 15-pound force. Position hoses and wiring
carefully to prevent rub- bing or chafing and
premature failurl
Fig. fi' Left-Hand Remo val Steps
10
SEPARATING ENGINE FROM CLUTCH HOUSING Use the for
lowing method of separation to permit working on
clu1ch or r elated parts. When removing the
engine, use the method explained un der Sepa-
rating Engine From Tractor Front End, and
Remov- ing Engine." Discharge the accum ulator.
Remove m uffler, air stack, grille screens,
co'wI, cab center panel, and hood. Disconnect
battery ground cable, and drain cooling
system. Disconnect hydraul ic pump inlet pipe at
filter relief valve to drain oil from cooler ard
reser voir. Disconnect the tront differential
drive shaft at the universal joint adjacent to
the ditferentiat housing.
Fig. 6-Pigfit Ha nd Pemo val Steps
1. On tractors with air conditio ning, remove
the compressor (Figs. 3 and 5) with hoses
attached, and place inside the cab.
2. Disconnect ether starting aid pipe at
connector, and remove clamp from pipe on firewall
.
3. Disconnect ground wire from air cleaner-to-
elbow bolt, and disconnect wiring from
restriction in- dicator switch.
Litho in U.S.d.
21
Tractor - 7520 PM- f 053 Jan- 73/
General 1g Separation 25-3
4. Loosen air cleaner elbow-to-turbocharger hose
c la m ps, an d re m ove c ap sc re ws fasten ing
the air cleaner elbow to engine cylinder head.
Remove air cleaner, elbow, and hose.
Drain fuel from both fuel tanks (capac ity of
each tank is 78 gallons) . Be sure to drain the
fuel down to a level below the crossover hoses.
Place a floor jack under tank support. Disconnect
vent hose and fuel inlet pipe from each tank
(Fig. 7) . Disconnect the fuel gauge sending u
nit wire from the left-hand tank, and disconnect
the crossover hoses from each fuel tank (Fig. 8) .
5. Disconnect front headlamp wiring at connector
below starter, and disconnect hydraulic pump
inlet pipe at connector next to clutch housing.
6. Disconnect wiring harness from connectors and
clamp (Fig. 6) .
Remov e tan k mo unt ing boIts an d cap sc rews.
Place tank in a stable position, and cover the
tank openings to prevent contamination by dirt,
water, or other foreign material.
7. Disconnect and remove fuel return pipe from
engine and fuel tank, (Fig. 6 and 7) . Disconnect
and remove crankcase vent hose and pipe.
I n stalI JDG -1-9 en gi n e Iift i n g brac k
ets. Attach JDG-1 engine Iift st ing to engine
lifting brackets and to an overhead hoist.
8. Disconnect temperature gauge sensing bulb
from water manifol d.
I ns tal I a wed ge o bloc k betwee n th e Iron
t axle housing and the engine side frame. A wedge
should be used on botn sides to prevent rocking
of front end.
9. Loosen hose clamps on both heater hoses (if
equipped), remove clamp from hoses on firewall,
and place hoses out of way.
Place a jac k under the front hinge. Use a
substan- tial metal stand to support the rear
portion of tractor. IMPORTANT Do not place ack
at front end of steer- in c linder frame.
10. Remove control support covers. Disconnect and
remove speed control rod and fuel shut-off cable.

• Disconnect tachometer cable.
• Disconnect cooler return pipe at hose connec-
  tion beMeen side frame and clutch housing.
• Disconnect fuel pump inlet pipe.
• Disc onn ec t the hy d ra uI i c p ump di s c ha
  rg e hose at manifold.
• Remove cap screws from manifold on top of
• side frame.

Fig. 8-0/sconnecring Side Frames From
Tractor Remove the side frame cap screws, and
the side frame-to-clutch housing cap screws (F
ig. 8). Remove the engine-to-clutch housing cap
screws.
Fig. 7'-Bleed line and Fuel Tenk Qonneotionc
Roll engine and tractor front end away from
clutch housing (Fig. 9).
Di sco nne ct th e hy d ra ulic pu mp s eal bleed
Ii ne (Fig. 7) .
Liffio in U.S.A.
22
10 General 25-4 Separation
Tractor
7520
TM- 1053
(Jan- 73)
Fig. 10-Left-Hand Side Aemova/ Steps
Fig. 9-Engine Separated From Glutch Housing
ASSEMBLY Apply a i igh t coating of Pe rmat ex to
en g ine and clutch housing mating surfaces, and
roll front and rear units together. Never use
excessive force. Reverse the removal steps.
Tighten cap screws to specification (page 30-1 )
. Install hood and cowl, muffler, air stack, and
fuel tanks. Connect battery ground cable, and
fill the cool- ing system. Start engine and check
tractor operation.

1. Remove fuel tanks (Fig . 10) , following instruc-
   tions given at the top of the right-hand column
   of pre- vious page.
2. Disconnect front headlamp wiring at connector
   below starter, and remove headlamp wiring bands
   from hydraulic pump inlet pipe.

3. Remove air conditioning compressor (Fig. 3)
with hoses attached, and place inside cab, if
engine is to be removed.

• Remove upper and lower radiator hoses.
• Remove the screws fastening fan shroud to ra-
  diator.
• Disconnect radiator support straps from radia-
• tor.
• Remove radiator and fan shrou d.

SEPARATING ENGINE FROM TRACTOR FRONT END Use the
following method of separation when desir- ing to
remove the tractor front end from the engine for
repair. Discharge the accumulator. Disconnect the
battery ground cable and drain cooling system.
Remove muf- fles, air stack, grille screens,
cowl, cab center panel, and hood. Disconnect the
battery cables and remove the rubber grommets
from cables. Remove the bat- tery cables from
battery compartment through the holes where
rubber grommets were positioned. Drain the
cooling system. Disconnect hydraulic pump inlet
pipe at filter relief valve to drain oil from
cooler and reservoir. Disconnect the front
differential drive shaft at the universal joint
adjacent to the differential housing.
Fig. 1Right-Hand Side Pemova/ Sieps
Litho in U.S.A.
23
Tractor - 7520 TM- 1053 (Jan- 73)
General 10 Separation 25-5
Loosen the side frame-to-front axle support cap
screws (Fig. 12) to prevent excessive binding of
side frames during removal. Remove the cap screws
fas- tening the side frames to engine mounting
pads. Place a chain around each side frame at the
front, as shown in Fig. 13, and attach to an
overhead hoist. Remove the side frame cap screws,
and the side frame-to-clutch housing cap screws
(Fig. 8) .
8. Disconnect cooler return pipe at hose connec-
tion between side frame and clutch housing (Fig.
11) .
9. Disconnect fuel pipe at connector and at pump.
10. Disconnect hydraulic pump discharge hose at
manifold and at pump. Remove discharge hose-to-
side frame clamps, and remove discharge hose and
fuel pipe.
Roll the tractor front end away from engine (Fig.
13) . Place a support stand under side frames in
front of differential.
11. Disconnect manifold from top of side frame by
removing the two cap screws.
Dis c onn ect th e hy d ra ul ic pu mp seal bl
eed Ii ne (Fig. 7) , and remove the spring clips
which fasten the bl eed Iin e to the to p fl an
ge of side f ra me. Remove bleed
line. Disconnect hydraulic oil cooler inlet hose
at pump. Ins tall a wed ge or bl oc k b etween
th e f ron t axl e housing and the engine side
frame. A wedge should be used on both sides to
prevent rocking of front end. Place a jack under
the front hinge. Use a substan- tial metal stand
to support the rear portion of tractor.
IMPORTANT Do not place jack at front end of
steer- ing cylinder frame.
NET A L WEDGE
S I DE FRAMC- T0 - ENG NC CA SCREWS
S 10E FRANE - T0 - AX LE SUPPORT CAP SCREWS
Fig. 13-Tractor Front End After Separation
F L00 R JACK PO S I T 1 0 NE 0 UND ER FRONT H I
NG E
Fig. 12-Engine and Axle Support Cap Screws
Fig. 14-Engine After Separation
Litho in U.S.A.
24
1o General 25-s Separation
Tractor
7520
TM-1053
(Jan-73)
ASSEMBLY Reverse the numbered removal procedures.
Tight- en cap screws to specifications.
5. Disconnect ground wire from air cleaner mount-
ing bolt and disconnect wiring from restriction
indica- tor switch.
6. Loosen hose clamps and remove air cleaner
elbow-to-cylinder head cap screws. Remove
air cleaner, elbow, and hose.
Install hood, cowl, cab center panel, grille
screens, muffler, and air stack. Connect battery
cables, and fill the cooling system.
Start engine and chec k tractor for leaks and for
proper operation. REMOVING ENGINE Follow
instructions given on page 25-4, under Sep-
arating Engine From Tractor Front End. After
the tractor front end has been removed from the
remain- ing part of the tractor, use the
following procedure to remove the engine.
Fig. 16- Right-Hand Side of Engine

• Disconnect wiring harness from connectors and
  clamp (Fig. 16) .
• Disconnect temperature gauge sensing bulb from
  water manifold.
• Loosen hose clamps on both heater hoses (if
  equipped) , remove clamp from hoses on firewall,
  and place hoses out of way.
• Remove control support covers, disconnect the
  speed control rod, and remove rod. Disconnect
  fuel shut-off cable.
• Disconnect tachometer cable.
• Disconnect and remove crankcase vent hose and
  pipe.
• Re move fuel tan k vent hose and f uel return
  pipe, if not already removed.
• Install JDG -1-9 ehgin e I ift ing brac kets.
  Attach JDG-1 engine lift sling to lift brackets
  and to overhead hoist.
• Remove the cap screws fastening engine to clutch
  housing, and remove engine (Fig. 17) .

Fig. 15-Lett-Hand Side of Engine
1. Disconnect battery cables from starter
(Fig. 15) .
2. Remove cap screw from hydraulic pump inlet
pipe clamp, and disconnect pipe at both ends. Re-
move pipe with starter cables attached.
3. Disconnect and remove hydraulic pump cou-
pling. Loosen and remove the pump mounting brack-
et-to-engine cap screws. Remove hydraulic pump
with bracket attached.
4. Disconnect ether starting aid pipe.
Litho in U.S.A.
25
Tractor - 7520 TM-1053 Jan-73
General 10 Separation zs-z
L l FT 1NG 8RACKET
NGINE
nd. is-rront Axle Support Upper Cap Screws
Fig. 17- Removing Engine ASSEMBLY Apply a light
coating of Permatex to clutch housing and engine
mating surfaces, and join together. Never use
excessive force. Reverse the removal steps.
Tighten Gap sGrews and bolts to
speGitication. For information on joining
tractor front end to en- gine and hinge, refer to
the preceding page.
REMOVING FRONT AXLE ASSEMBLY WITH AXLE
SUPPORT The /ronf axle assembly may be removed
'ith or 'ithout the axle support (Fig. 18).
Remove the axle assembly with axle support 'hen
u'or/t is to be done on the engine without
removing side frames. Remove the axle assembly
without the axle support 'hen re- pair is to be
made on the axle assembly only.
Fig. !9-Removing Fzonr Axle Assembly With Axle
Support

• Refer to Figs. 18 and 19 while performing the
  fol- lowing steps
• DiSconneGt the front differential drive shaft at
  the universal joint next to the differential
  housing.
• Remove the two upper cap screws (Fig. 18) .
• Wrap a chain around each side frame and sup- port
  with a suitable overhead hoist. Do not lift from
  front crossmember.
• PIace a jac k under t he fro nt hinge to h el p
  lift and support the tractor front end.
• Remove the six cap screws on each side frame
  fastening the front axle support to the engine
  side frame (Fig. 12) .
• Raise the tractor front end and roll axle assem-
  bly out from under tractor (Fig. 19) .

CAUTION When removing or lnstalllng front axle
assembly wilh axle support, the differen- tial
and axle support will turn upside down If
a9eembly is allowed to gel out of balance. Keep
dlfferentlal end axle support balanced or
supported to prevent poasi ble injury.
Litho in U.S.A.
26
10 General 25-8 Separation
Tractor
7520
TM- 1 053
(Jan -73)
Remove the eight cap screws fastening the differ-
ential rear support to the axle support (Fig. 21)
.
ASSEMBLY Reverse the removal steps. Tighten the
axle sup- port-to-side frame cap screws to 300
ft-lbs torque. Be sure differential drive shaft
universal joints are cor- rectly "timed." Tighten
universal joint cap screws to 70 ft-lbs torque.
Disconnect the front differential drive shaft at
the universal joint next1o the differential
housing.
REMOVING FRONT AXLE ASSEMBLY WITHOUT AXLE
SUPPORT AXLE SJPPORT
LlFTI NG CHATNS
FRONT AX LE AS SENB LY
FRONT D I FF E R ENT I AL SUPPORT
FLOOR JA CK UND ER FR0 NT H I NG E
Fig. 22-Removing Front Ax/e Assembly Without Axie
Support Raise the tractor front end as shown in
Fig. 22, and roll front axle assembly out from
under tractor.
Fig. 20-Differential Front Support
ASSEMBLY Roll front axle assembly back under
tractor, and reverse the removal procedures.
Tighten the differen- tial front support-to-axle
support bolts to 170 ft-lbs torque. Tighten the
differential rear support-to-axle support cap
screws to 300 ft-lbs for 3/4-inch screws, and to
445 ft-lbs for 7/8-inch screws.
Be sure differential drive shaft universal joints
are "in time". Tighten universal joint cap screws
to 70 ft- lbs torque.
Fig. 21-Differential Rear Support
Remove the bolts fastening the differential front
support to the axle support (Fig. 20) . Wrap a
chain around each side frame and support with a
suitable overhead hoist. Do not lift from the
front crossmember. Place a floor jack under the
front hinge to help lift and support the tractor
front end.
Litho in U.S.A.
27
General 10 Separation 25-9
Tractor - 7520 TM-1053 (Jan-73)
SEPARATING TRANSMISSION AND DIFFERENTIAL FROM
TORQUE DIVIDER Install hinge lock pin.
NOTE When the torque divider input shalt
lubrica- tion pipe has been d/sconnec/ed from the
oil (ilter re- liei valve housing, the
transmission pump c/?eck valve and spring ma y o
r ma y no I drop out. Be s ure th at these parts
are in place beiore connecting pipe.
Discharge accumulator (open right-hand brake blee
d sc rew, and h ol d b ra ke pe dat do w n fo r a
few minutes) .
R0 CKS AFT CON TR0 L LEDER CAB LE
TRA NS NI S S I 0 N CAS E COV ER
Drain the transmission. Remove the drawbar and
drawbar support. Install JDG-2M rear support
stand under transmission case (Fig. 25) .
HOSES AND - BRACKET
PTO SHIFTER
START - SAF STY SHI T CH HI RE
TRUSS ROD AND BRA CKET BRAKE PRtSSURE P
IPE SELECT l VE CONT R0L VA LV E RET URN P I PE
COOLER RETURN IPE
TRANS I SS I ON SH F TER CA6LES
LOU/ RAf,GE P I N I 0N LUBR I CAT 0L P I PE
S TEER I NG AND 3 JAKE RETURN P lPE
Fig. 24-Right-Hand Side of Transmission Case
I NPUT SHAF T LUBR I CAT I 0N P I PE
Disconnect the start-safety switch wire and
trans- mission shifter cables from arms (Fig. 24)
. On trac- tor with a rockshaft, disconnect the
rockshaft con- trol lever cable.
PUMP I N LET
Remove the transmission case cover and remove the
two cap screws inside transmission case which
fasten case to torque divider.
Fig. 23-Left-Hand Side of Transmission Gase
Disconnect remote cylinder outlets from top of
dif- ferential housing, leaving hoses attached.
Remove hose guide. On tractors with a rockshaft,
disconnect pres s ure hoses f ro m rem ote cyl i
nder outl ets and roc kshaft. After capping the
hoses, remove the hoses and bracket (Fig. 23) ,
and place out of way.
Disconnect the front differential drive shaft at
uni- versal joint next to front hinge.
PI ace a sub stan t ial j ac k unde r f ro nt h
inge, and place an adequate support stand under
rear hinge.
Remove the three long cap screws (Fig. 26) which
fasten the transmission case and torque divider
to the rear hinge. Then remove the cap screws
fastening the transmission case to the torque
divider housing. Roll tractor rear end away from
torque divider housing (Figs. 25 and 26) .
Disconnect the hydraulic cooler return pipe
steer- ing and return pipe, brake pressure pipe,
hydraulic pump inlet pipe, selective control
valve return pipe, and lubrication pipes for
torque divider. Remove rock- shaft-to-rear hinge
truss rods with brac ket.
Litho in U.S.A.
28
\ 0 General 25-10 Separation
Tractor - 7520 TM-1053 (Jan-73
Be sure differential drive shaft universal joints
are "in time. Tighten universal joint cap screws
to 70 ft- lbs torque. IMPORTANT When Installing
drive shafts, arrows (Flg. 27) must point
together on all drive shafts. Each drive shaft
assembly Is a balanced unit. Do not permit shaft
assemblies to become intermlxed. ARgOVS MST NT
TOGETHER
JDG -2N SUPPORT STAND
Fig. 27-Drive Shatt Arrow's
Tighten cap screws and bolts to specification.
Re- move hinge lock pin, and JOG-2M support
stand. In- stall drawbar support and drawbar.
Fig. 25-Rear Section ol Tractor Afler Separation
(Tractor without Rockshaft)
Fill transmission with oil to correct level.
Check tractor for proper operation.
HI -L0 SHIFTER LINKAGE
SEPARATING TORQUE DIVIDER AND TRACTOR REAR END
FROM HINGE Install hinge lock pin.
t0NG CAP SCREWS
Discharge accumulator (open right-hand brake
bl eed sc rew, and hold brake pedal down for a
few minutes).
Drain the transmission. Remove the drawbar and
drawbar support. Install JOG-2M rear support
stand under transmission case (Fig. 25).
SUPPORT STAND
Disconnect the oil cooler return pipe, steering
and brake return pipe, hydraulic pump inlet pipe,
selective control valve return pipe, and the
brake pressure pipe from left-hand side of
tractor (Fig. 23). Install cap- lugs to prevent
entry of foreign material into hydraulic system.
Fig. 26-Front Section ol Tractor A/ter Separation
ASSEMBLY Reverse the removal steps. Be sure that
transmis- sion pump check valve and spring are
installed in oil filter relief valve housing
before installing torque di- vider input shaft
lubrication pipe.
Disconnect transmission shifter cables, rockshaft
control lever cable (if equipped) , PTO shifter
clevis, and start-safety switch wire (Fig. 24) .
Remove cap screws securing shifter cable clamps
to the torque
Litho in U.S.A.
29
Tractor - 7520 TM- 1053 /u/an- 73
General 1o Separation 25- 11
ASSEMBLY Reverse the removal steps. Remove
caplugs from pipes and fittings.
divider case. Disconnect the Hi-Lo shifter
linkage (Fig. 26) . Disconnect both drive shafts
at the univer- sal joints inside hinge next to
the torque divider case. On tractors with
rockshaft, disconnect hoses from remote cylinder
outlets, and rockshaft pressure hose. Disconnect
rockshaft-to-rear hinge truss rods.
Be sure differential drive shaft universal joints
are in time". Tighten universal joint cap screws
to 90 ft- lbs torque.
Remove cap screws fastening torque divider and
tractor rear end to hinge. Roll unit bac k away
from hinge (Figs. 28 and 29) .
IMPORTANT When installing drive shafts, arrows
(Fig. 27) must point together on all drive
shafts. Each drive shaft assembly is a balanced
unit. Do not permit shaft assemblies to become
intermixed.
Tighten cap screws and bolts to specifications.
Flemove hinge lock pin, and JDG-2M support stand.
Install drawbar support and drawbar. Fill
transmission with oil to correct level. Check
tractor for proper operation.
SEPARATING CLUTCH HOUSING FROM FRONT HINGE To fac
il it ate r emov al of the c Iu tch hou si ng c
ap screws and pipes inside the front hinge, turn
the trac- tor to the extreme right. Shut off
engine.
SUP P 0 RT STAN 0 ,
Fig. 28-Front Section ol Trac for After
Separation Discharge the brake accumulator (open
right-hand brake bleed screw and hold brake pedal
down for a few minutes) . Separate the engine
and tractor front end from the clutch housing.
See page 25-2. Remove Roll-Gard cab. See page
25-1.
Disco nnect th e pipes from b ra ke reservoir and
pressure control valve. Disconnect the
transmission and PTO shift-cables. Disconnect
drive shafts at the front hinge.
SUPPORT STAN 0
Disc on nect pipes, hoses, and w ir ing from
front hinge that are connected to the control
support.
Fig. 29-Rear Section ol Tractor After Separation
Disconnect the control support from clutch hous-
ing. Install control support lift brac ket (Group
30, Fig. 1) , and attach to an overhead hoist.
Remove control support.
Remove th e c ap sc rews th at fasten the c lutch
housing to the front hinge, and remove clutch
hous- ing.
Litho in U.S.A.
30
10 Genera/ 25-12 Separation
Tractor
7520
TM-1053
(Jan-73)
ASSEMBLY Reverse th e re moval proced ures. Tigh
ten the clutch housing-to-front hinge cap screws
to300 ft-lbs torque.
After the tractor has been completely assembled,
check for leaks and test operation. REMOVING
FINAL DRIVE ASSEMBLY Drain the transmission.
Raise tractor enough to remove rear wheel.
REAR AXLE HOUSING
Fig. 30-Rear Axle Housing
INSTALLING FINAL DRIVE Reverse the removal
procedure.
Wrap a chain around the axle housing, and attach
to an overhead hoist. Remove the cap screws
fasten- ing the rear axle housing to the
transmission case. Hold backing plate to
transmission case when remov- ing the housing.
IMPORTANT To prevent serious damage when
installing the final drive housing, be sure that
the sun pinion does not work outward far enough
to allow the brake disk to drop inside the sun
pinion teeth.
Remove s un pin ion, brak e bac king plate, and
brake disk.
Tighten axl e ho usi ng cap sc rew s to 17 0 ft-
Ibs torque.
To remove the front final drive assembly, remove
th e front axle assembly witho ut axle su ppo rt,
de- scribed on page 25-8. Then remove the final
drive as described on this page.
Litho In U.S.A.
31
Tractor - 7520
General 10 Specifications and Special Tools 301
Group 30 SPECIFICATIONS AND SPECIAL TOOLS
SPECIFICATIONS
item Air conditioning compr