GM Service Manual Online
For 1990-2009 cars only

Composition Plates

Dry and inspect the plates for the following conditions:

    • Pitting
    • Flaking
    • Wear
    • Glazing
    • Cracking
    • Charring
    • Chips or metal particles embedded in the lining

Replace a composition plate which shows any of these conditions.

Steel Plates

Wipe the plates dry and inspect the plates for head discoloration. If the plate is discolored with hot spots or if the surface is scuffed, replace the plate. If the surfaces are smooth, even if color smear is indicated, the plate is reusable.

Causes of Burned Clutch Plates

The following conditions can result in a burned clutch plate:

    • Incorrect usage of clutch plates
    • Engine coolant in the transaxle fluid
    • A cracked clutch piston
    • Damaged or missing seals
    • Low line pressure
    • Worn or damaged seal rings
    • Valve problems
       - A valve body face which is not flat
       - Porosity between channels
       - Improperly installed valve bushing clips
       - Misplaced check balls

Engine Coolant in Transaxle

Notice: The antifreeze will deteriorate the Viton O-ring seals and the glue that bonds the clutch material to the pressure plate. Both conditions may cause damage to the transmission.

If the transmission oil cooler has developed a leak allowing engine coolant to enter the transmission, perform the following:

  1. Disassemble the transmission.
  2. Replace all of the rubber type seals. The coolant will attack the seal material which will cause leakage.
  3. Replace the composition-faced clutch plate assemblies. The facing material may separate from the steel center portion.
  4. Replace all of the nylon washers.
  5. Replace the torque converter.
  6. Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.
  7. Flush the cooler lines after the transmission cooler has been properly repaired or replaced.