This bulletin is for GM Canada Only
This bulletin contains information on:
Preliminary diagnostic procedures for the optional 4-speed automatic transmission used in the 1988-92 W4 Forward Trucks.
Transmission exchange procedures which will go into effect in the event an internal transmission repair is required.
Until further notice, any W4 Automatic Transmission requiring internal repair, is to be replaced with an exchange unit.
The exchange program will be administered through the GM Technical Assistance Centre.
1. Preliminary diagnostic procedures are as follows: Prepare diagnostic form IST SVC 180 11-89 (Figure 1) by completing all required information.
2. All incidents must be documented using diagnostic form IST SVC 180 11-89 and a T.A.C. case must be opened.
3. Dealership repair authority is limited to labour operations listed at the end of this bulletin.
4. Refer to Service Manual for additional specifications and servicing information.
5. A diagnostic form is included in this bulletin.
a. Additional forms are available through your T.A.C. operator. They will be mailed to you when T.A.C. case is opened.
WARRANTY EXCHANGE PROCEDURES:
1. Contact GM Technical Assistance Centre (TAC) as soon as you have determined that the service required is beyond your authority level.
At the time of contact, you should have the completed diagnostic form in front of you with as much of the information completed as possible. This is necessary to permit order placement/ verification.
2. Following verification of information, the TAC operator will provide a TAC case number and arrange shipment of an exchange unit to your dealership.
3. The exchange unit will be shipped in a reusable container. Open a repair order to cover vehicle repairs and transmission shipping both ways.
4. Upon receipt of the exchange unit, the inoperative transmission must be properly tagged and repacked in the reusable container and shipped prepaid to: G.M.C. Truck Centre 1650 The Queensway TORONTO, Ontario M8Z 1X1
TO AVOID A DEBIT TO YOUR PARTS ACCOUNT FOR A COMPLETE ASSEMBLY, the removed transmission must be shipped within 7 working days following receipt of the exchange unit.
DIAGNOSTIC FORM AND REPAIR ORDER:
Attach a soil proof envelope and insert copy of diagnostic form and repair order.
RETURN SHIPMENT PREPARATION:
1. Drain the oil.
2. Remove the plastic shipping plugs, fixture tying torque converter to housing, and companion flange from the exchange unit and install into the removed unit.
3. Secure (tape) the electrical harness to the housing of the transmission to prevent packing damage.
4. Insert the diagnostic form into the soil-proof envelope and firmly wire to the removed unit.
5. Pack the removed transmission in the reusable container.
6. Place shipping label on container.
WARRANTY CLAIM PROCESS
Follow standard claim processing procedures.
LABOUR OPERATIONS - DEALER AUTHORITY LEVEL W4 WITH JATCO A/T
Cover and/or Gasket P.T.0 Seal, Extension Rear Housing Pan and/or Gasket, Transmission Oil Switch, Transmission Oil temp. Transmission Assembly - Replace Converter Assembly - Replace Seal, Transmission Oil Pump Replace Oil Pressure Test
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.