Fluid leaks from the oil pump body seal may be created by movement of the pump body bushing. If this condition is experienced, a new oil pump body should be installed.
To service a 1984 (after Julian date 180) through 1986 (Julian date 006) THM 700-R4 transmission, use a new pump body assembly, part number 8649950. The new pump body has a stepped bore incorporated to assist in retention of the pump body bushing. It also is supplied with a new seal, part number 8648394 and a Helix seal retainer, part number 8654491 for improved sealing. The seal and retainer are available separately.
For identification of the transmission and Julian date, refer to Figure 1.
Because of the stepped bore in the new oil pump body, the installation procedure and tool for the pump body bushing have been changed. Installation of a bushing in a stepped bore body requires use of the new Kent-Moore tool J 34196-12, refer to Figures 2 and 3. The removal procedure is the same as outlined in the service manual.
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.