A/T - 4T60 3-2 Tip-In Flare/Slip-Bump at 18-24 MPH
BULLETIN NO.: 9174T60-02CORP. REF. NO.: 177102
DATE: Jan., 1991
TRANSAXLE APPLICATIONS: 1990-91 HYDRA-MATIC 4T60 (ME9)
TRANSAXLE MODELS:
CJH, CHH, LMH, LNH, YDH, YHH, YLH, YKH, YSH, YTH
SUBJECT:
3-2 Tip-In Flare/Slip-Bump At 18-24 MPH,
- Install New Parts
VEHICLE APPLICATIONS: 1989-91 A and W-Cars
BULLETIN COVERS:
Some 1989 through 1991 A or W-cars equipped with a 2.8L (VIN W) or 3.1L (VIN T) engine and a HYDRA-MATIC 4T60 transaxle may exhibit a 3-2 light throttle tip-in flare/slip-bump condition at 18-24 MPH. A new 3-2 line control system and spacer plate are now available that will better control the transaxle operation. These conditions can be corrected by replacing the components listed under "Service Procedure".
SERVICE PROCEDURE: (Figure 1)
To repair a 3-2 light throttle tip-in flare/slip-bump condition at 18-24 MPH, order and Install the parts for the appropriate model listed under "Service Parts Information".
IMPORTANT
Do not interchange parts between the two different 3-2 line control systems located in the channel plate assembly or the following two misbuilds could occur:
1) All upshifts at the minimum shift speed (early) for any throttle position. This would be caused by the 3-2 line control valves (both primary (431) and secondary (436) being used with the spacer plate assembly for the plug line control valve (430); the valves will not work correctly because there are no fluid passage holes in the spacer plate assembly designed to function with the plug valve.
2) All 2-3 upshifts at minimum shift speed (early) for any throttle position. This would be caused by using the 3-2 line control plug (430) with the new spacer plate assembly designed to function with the 3-2 line control valves (both primary (431) and secondary (436)).
DATE OF PRODUCTION CHANGE:
The new 3-2 line control system and spacer plate were implemented into production starting December 13, 1990 (Julian Date 347).
3-2 Tip-In Flare/Slip-Bump At 18-24 MPH,
- Install New Parts
SERVICE PARTS INFORMATION:
IMPORTANT
If servicing a CHH, CJH, YKH or YLH model built before March 27, 1989 (Julian Date 086), order and install package 8662992 for CHH or YKH and 8662993 for CJH or YLH models. Do not use the valve body spacer plate assembly from these packages; use the appropriate spacer plate from the packages listed below, along with all the components included in the package.
Part numbers 8662992 and 8662993 are currently available from GMSPO.
Part numbers 8675992 and 8675993 are expected to be available on 01-28-91. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.
SERVICE NOTES:
Use applicable labor operations and times.
The 3.1L (VIN V) turbo W-car models 0LAH and 0YRH will be addressed in a later bulletin for the 3-2 tip-in flare/slip-bump concern.
3-2 Tip-In Flare/Slip-Bump At 18-24 MPH,
- Install New Parts