A/T - Updated Oil Pump Assemblies
87chevy20Number: 88-56
Section: 7A
Date: Sept., 1987
Subject: NEW PUMP ASSEMBLY VANE RINGS
THM 700-R4 THM 200-4R
Model and Year: 1981-88 PASSENGER CARS AND L.D.
TRUCKS EQUIPPED WITH EITHER THM 700-R4 OR THM 200-4R TRANSMISSIONS
TO: ALL CHEVROLET DEALERS
New transmission oil pump assemblies with Nodular Iron Vane Rings entered production April 28, 1987 (Julian date 118) on THM 700-R4 transmissions. This change also applies to SRTA.
FIGURE 1 - THM 200-4R AND THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION:
Beginning June 17, 1987 (Julian date 168) all THM 200-4R began production with the new rings. (Refer to Figure 1)
FIGURE 2 - 200-4R PUMP BODY ASSEMBLY:
FIGURE 3 - 700-R4 PUMP BODY ASSEMBLY:
The new design vane rings (item 212, Figures 2 and 3) will reduce the possibility of vane ring distress and can be used on any 1982 through 1987 THM 700-R4 transmission or any 1981 through 1987 THM 200-4R transmission, and it is recommended that the new iron pump vane rings be used when replacement of the vane rings becomes necessary.
PARTS INFORMATION:
THM 700-R4 transmission only:
8657531 Pump Vane Ring (2 required)
THM 200-4R transmission only:
8657692 Pump Vane Ring (2 required)