TRANSMISSION APPLICATION: 1991-92 HYDRA-MATIC 4L60 (MD8)
TRANSMISSION MODELS: All
B, F, Y - Cars C/K, S/T, R/V - Trucks G, L, M - Vans
In response to product changes made to the 1991 HYDRA-MATIC 4L60 stator shaft, a new essential tool has been released to remove the pump assembly. The groove under the stator shaft splines has been removed, so the previous tool cannot fit onto the new shaft. The new tool is an adapter for use with the current HYDRA-MATIC 4L80-E pump puller.
Tools necessary to remove the HYDRA-MATIC 4L60 pump assembly include:
HYDRA-MATIC 4L80-E Pump Puller HYDRA-MATIC 4L60 Adapter HYDRA-MATIC 4L60 Forcing Screw
Dealers already have the HYDRA-MATIC 4L80-E pump puller as an essential tool. These dealers will receive only the HYDRA-MATIC 4L60 adapter and forcing screw.
The HYDRA-MATIC 4L60 forcing screw is longer than the screw on the HYDRA-MATIC 4L80-E pump puller to accommodate the shorter splines on the stator shaft.
The previous pump puller is still needed, however, for end play measurement, and is used on several other transmissions for pump removal.
Tools have been shipped to dealers.
Dealers currently servicing the HYDRA-MATIC 4L80-E will receive:
J39119 - Oil Pump Remover and Installer Adapter (HYDRA-MATIC 4L60 Adapter)
J37789-4A - HYDRA-MATIC 4L60 Forcing Screw
For dealers currently servicing the HYDRA-MATIC 4L80-E:
When the new pump puller tools arrive at your dealership, unscrew the forcing screw from your HYDRA-MATIC 4L80-E pump puller and install the new forcing screw.
The following procedure should be used after the transmission has been removed from the vehicle, and is secured to the workbench in a holding fixture. The fluid filter assembly and TCC solenoid must be removed before removing the pump.
1. Rotate the transmission so the bell is facing up. 2. Remove the torque converter. 3. Remove the 0-ring seal on the turbine shaft. 4. Remove the pump bolts. 5. Install the HYDRA-MATIC 4L60 adapter by slipping it over the stator shaft. 6. Install the HYDRA-MATIC 4L80-E pump puller over the adapter. 7. Tighten the small screw to secure the pump puller to the adapter. 8. Turn the forcing screw to lift the pump out of the case.
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.