NO REVERSE/SLIPPING IN REVERSE REPEAT REVERSE BAND DISTRESS
TRANSMISSION APPLICATIONS: SUBJECT: 4T60 NO REVERSE, SLIPPING IN REVERSE AND/OR REPEAT REVERSE BAND DISTRESS (REPLACE CASE)
TRANSMISSION MODELS: VEHICLE APPLICATIONS: 1987-91 A,C,E,H,K,W CARS W/4T60
Bulletin Covers:
A vehicle equipped with a 1987-91 HYDRA-MATIC 4T60 transaxle may exhibit no reverse, slipping in reverse and/or repeat reverse band distress. This may be caused by interference between the reverse band apply bracket and the case. The suspected transaxle cases have an additional wall thickness in the area where the reverse band apply pin engages the apply bracket. The band may never fully apply or release once caught and will distress the fiber liner material across all straps.
SERVICE PROCEDURE:
If the transaxle exhibits any of the symptoms discussed in this bulletin, inspect the case die number as shown in Figure 1 and the transaxle Julian Date. If the case die number matches the suspect numbers and the transaxle Julian Date is after the dates listed, disassemble the transaxle and check the case spline number, as shown in Figure 2 (located deep inside the barrel of the case next to the right axle seal). If it is listed below, replace the case : If the transaxle is not a suspect unit, then refer to the Automatic Transaxle Diagnosis section of the Service Manual for repair procedures.
DIE SPLINE JULIAN JULIAN # # DATE DATE DATE DATE --- ----- ------------ ------ ------------------ ----- 527 4543 July 25,1988 207 to Nov. 5, 1988 309 557 4542 Mar. 19,1990 078 to June 10,1990 161 558 4541 Jan. 29,1990 029 to June 10,1990 161 561 1524 July 15,1987 156 to June 10,1990 161 590 4542 Mar. 06,1989 065 to Feb. 18,1990 049 594 4544 Jan. 15.1990 015 to June 10,1990 161
SERVICE PARTS INFORMATION:
Part Transaxle Number Description Model Year Model Usage ------- --------------- ---------- ----------- 8668986 Case, Transaxle 1990 OLAH
8662928 Case, Transaxle 1987-90 All with previous Park System built before Sept.25,1989 (Julian Date 268)
Reference Hydra-Matic Service Bulletin 90-7440-105 for more information on the new park lock system.
8668985 Case, Transaxle 1990-91 All except OLAH with (common case for new Park System built new park system) after Sept.24,1989 (Julian Date 267)
SERVICE MANUAL-REFERENCE
Refer to the appropriate Service Manual for proper procedures.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
