A/T - Fluid Leak At Side Cover to Channel Plate Gasket

NUMBER:
92-T-51A

CORP.REF.NO:
277102R

DATE:
September 1992

SECTION:
7, 4T60/4T60E



SUBJECT
TRANSAXLE FLUID LEAK AT SIDE - COVER TO CHANNEL PLATE GASKET - INSTALL NEW SIDE - COVER PAN

MODELS/YEARS
1991-92 MODELS WITH 4T60 & 4T60E TRANSAXLES



This bulletin cancels and supersedes Dealer Technical Bulletin 92-T-51 which should be discarded.

CONDITION:
Upon inspection or notification by customers, technicians may find automatic transmission fluid seeping from the side pan of 4T60 and/or 4T60E HYDRA-MATIC transaxles. In some situations, the leak may be mistaken for distressed 4th clutch (refer to Dealer Technical Bulletin 90-T-57 for more information on distressed 4th clutch). Depending on the amount of fluid lost, a customer's vehicle may exhibit any of the following conditions:

^ Delayed Engagement (verify leak side-cover)

^ Intermittent Flares on Shifts

^ No Drive In Drive Range

^ Intermittent Loss of Drive

^ Slips In Drive

^ Repeat Side-Cover Pan Leak

Note
If vehicle is driven with a low fluid level for an extended period of time, internal damage may occur and a complete overhaul or SRTA replacement transaxle may be required.

CAUSE:





See Figure 1. The side-cover to channel plate gasket may be split or torn due to a raised surface or ridge on the sealing side of the pan assembly. This raised edge can apply additional pressure on the gasket and a tear may develop. Vehicle mileage and vibration are factors which can accelerate the potential of the gasket to tear. The entire inner case side cover gasket is suspect and should be inspected carefully for this condition.

CORRECTION:
See Figures 1 and 2. Install a new case side-cover pan which does not have the stamping "DO NOT PRY IN THIS AREA." Removing this stamping has improved flatness on the sealing surface of the side pan and has reduced (but not eliminated) the opportunity of side pan leaking. It should NOT be assumed the removal of the "DO NOT PRY IN THIS AREA" is a 100 percent fix. Vehicles with side pan leaks, regardless of stamping, should be considered suspect for this condition. If transaxle already has a new style pan and a leak occurs at the inner side pan gasket, a second side pan (again, without the stamping) may need to be installed to correct the concern.

Note:
Even though the stamping "DO NOT PRY IN THIS AREA" has been removed, it is NOT acceptable practice to pry in the described area when removing axle and/or seal.

Important:
Tightening the inner case side cover gasket nuts may appear to fix the leak. However, fix will be short term and customer will be back.

Remember:
Do not exceed the recommended torque specifications (listed below) for the pan nuts and bolts. Exceeding these specifications will contribute to further gasket splitting and render any repair procedures useless.

4T60 4T60E Description
(53) (50) Case side cover to channel plate
(nut) 8-14 N-m (71.0-124.0 lb.in.)

(52) (52) Screw and conical washer assembly
(bolt) 9-13 N-m (80.0-115.0 lb.in.)

SERVICE PARTS INFORMATION:
Parts are currently available from GMSPO.

Part Number Description Models
8680513 Pan-Case Side Cover All
8644902 Package Side Cover Gasket All

WARRANTY INFORMATION:
See the current Labor Time Guide.