Date of Production Change: (Figure 1)
January 6, 1986, Julian Date 006, A machined step in the oil pump body.
October 10, 1985, Julian Date 283, A new front pump seal assembly.
February 11, 1986 Julian Date 042, A new front pump seal retainer.
To service a 1982 through 1984 (before Julian Date 180) THM 700-R4 transmission, refer to the latest GM Parts Catalogue.
To service a 1984 (after Julian Date 180) through 1986 THM 700-R4 transmission use the pump body assembly. The new seal assembly and retainer are included with the pump body assembly or are available separately.
Service Parts Information: (Figure 2)
8649950 Pump Body Assembly
8648394 Seal Assembly
8654491 Seal Retainer
Service Manual Reference:
Refer to the THM 700-R4 Automatic Transmission Repair table of contents for Oil Pump Assembly.
Service Notes: (Figure 3)
Because of the stepped bore in the oil pump body, the installation procedure installation procedure use the new Kent-Moore tool J 34196-12. 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.