A/T - Intermittent Delayed Engagement In Drive/Reverse

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Bulletin:
92-74T60-9

Date:
Apr. '92

Ref. No.:
92-199-74T60

Corp. Ref. No.:
277116


SUBJECT:
INTERMITTENT DELAYED ENGAGEMENT IN DRIVE/REVERSE (REPLACE INPUT CLUTCH OUTER PISTON SEAL)

MODELS AFFECTED:
1991-92 CENTURY, REGAL, LESABRE, PARK AVENUE/ULTRA AND RIVIERA/REATTA WITH 4T60/4T60E TRANSAXLE


THIS BULLETIN CANCELS AND REPLACES BULLETIN 92-74T60-2.





CONDITION: (Figure 1)

Some vehicles equipped with a HYDRA-MATIC 4T60/4T60E transaxle built before November 1, 1991 may experience an intermittent delayed engagement in drive and/or reverse after a "cold" soak overnight. The condition may gradually become more noticeable as vehicle mileage increases, and as ambient temperature decreases.

NOTE:
Once transaxle is brought to operating temperature, the condition may not be able to be reproduced until a "cold" soak overnight is performed.





CAUSE: (Figure 2)

The above condition may be caused by a rolled or cut input clutch outer piston seal.

NOTE:
An air check of the input clutch outer piston seal could be misleading, due to the position of the seal, and should not be used as a factor to determine proper function. Also, the seal may look good during visual inspection but should be replaced if the above condition is present. The seal may have rolled back into the proper position during disassembly.


The following is a list of items which may also affect the engagement time into drive and/or reverse:

4T60
- Fluid level low
- Cooler checkball (569) not seating properly allowing converter drain back
- Reverse servo assembly seal (547) cut or damaged
- 1-2 servo, assembly seal (557) cut or damaged
- Seal assembly 1-2 servo pipe (383) cut or damaged
- Pipe, 1-2 servo apply (136) split or damaged
- Retainer and ball assembly (625) damaged (in the input shaft and housing assembly)

4T60-E
- Fluid level low
- Cooler checkball (28) not seating properly allowing converter drain back
- Reverse servo assembly seal (43) cut or damaged
- Forward servo assembly seal (18) damaged or cut
- 2-1 servo seal (105) damaged or mislocated
- Retainer and ball assembly (633) damaged (in the input shaft and housing assembly)

CORRECTION:

To repair this condition, replace the input clutch outer piston seal. Refer to the appropriate Service Manual under "Automatic Transaxle Unit Repair" for the proper disassembly and assembly procedure.

LABOR TIME INFORMATION:

Labor time should be charged under Operation Number K7536, "Input Clutch Piston Outer Seal-Replace" from the 1991-92 LABOR TIME GUIDE manual.