Automotive Trans. The Beginning

1
Automotive Trans. The Beginning
2
Common terms - Define

• Transmission
• Transaxle
• Transfer case
• Common configurations
• Longitudinal vs. transverse
• Front vs. mid vs. rear engine

3
Terms - Define

• ATF
• Clutch (automatic trans.)
• Band
• Friction material
• Hard part
• Slipping
• Flex plate vs. flywheel

4
Terms - Define

• Valve body
• Overdrive
• Gear ratio
• Cooler
• Upshift
• Downshift

5
Fluids job

• Lubricate
• Cool
• Clean
• Provide coupling
• Control clutch / band engagement
• Perform all hydraulic functions

6
Fluid level checks

• Typical Procedure
• Trans at operating temp.
• Vehicle level
• Run through ALL gears, vehicle running
• Check in ??
• Sometimes there will be cold marks
• Add line means add one what??
• Low fluid usually means ?? Why??

7
Fluid condition

• ATF is usually red. Why??
• Somewhat dark and brown - old fluid
• Very dark or black - burnt
• Smells burnt - burnt (duh)
• Full of small bubbles - Aerated (low/high fluid
  or filter leaks)
• Feels gritty - Friction material
• Black specs - Friction material

8
Fluid condition

• Many silvery specs - Hard parts
• Milky fluid - Cooler problems
• Dipstick black and varnished - ATF overheated /
  oxidized

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ATF types

• ATF can be petroleum, synthetic or a combination
  of the two
• Three types of fluid typically used today
• 1. DexronIII - Mercon
• 2. Type F
• 3. ???
• Biggest difference is friction modifiers
• All brands are certified for miscibility

10
Trans servicing

• Standard interval is ?? miles.
• Usually includes pan removal, inspection, gasket
  and filter change.
• Few automatics have drain plugs
• Older transmissions also required periodic band
  adjustments
• Always inspect fluid in pan before discarding

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Trans service tips

• Check new seals on filter for proper fit
• Dont double gasket/seal it
• DONT USE GASKET SEALERS
• Pound steel pan mating surface flat
• Dont over torque pan, especially ribbed pans /
  cork or rubber gaskets (no air)
• Stay away from most additives
• Quick road test before and after
• Triple check fluid levels