SLIP/BUMP DURING 3-2 DOWNSHIFT VALVE AND PUMP P/N
MODELS AFFECTED: 1988 SKYLARKS EQUIPPED WITH 2.3L (VIN CODE D), OR 3.OL (VIN CODE L) ENGINES, AND THM 125C (MD9) TRANSAXLE MODELS BHC, BJC, KDC
BULLETIN COVERS
A Slip Bump condition during a part throttle 3-2 downshift (Forced Throttle) maneuver, may be caused by excess material left in the 3-2 control valve bore during machining of the Control Valve and Oil Pump Assembly.
DATE OF PRODUCTION CHANGE (Figure 1)
November 11, 1987 (Julian Date 315) corrected control valve assemblies went into production.
SERVICE ACTION
To repair this condition on a 1988 N Car with a 2.3L or 3.OL Engine and equipped with a THM 125C with a listed Julian Date lower than 315 install a new Control Valve and Oil Pump Assembly.
SERVICE PARTS INFORMATION (Refer to Figure 2)
When ordering a new Control Valve and Oil Pump Assembly refer to the following part list:
Part No. Package Description Models -------- ------------------- ------ 8664791 Control Valve and Oil Pump Assembly BHC 8664791 Control Valve and Oil Pump Assembly BJC 8664794 Control Valve and Oil Pump Assembly KDC
SERVICE MANUAL REFERENCE
When servicing a 125C transaxle for this condition replace the Control Valve and Oil Pump Assembly. Refer to the procedure given in 125/125C Unit Repair Section of your Service Manual.
WARRANTY INFORMATION
Labor Operation Number: K6570.
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.
