Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
results in a higher push-out load.
DATE OF PRODUCTION CHANGE: (Figure No. 1)
Beginning August 1, 1988 (Julian Date 213) all 1989 THM 400/475 transmissions were built with the new pump bushing.
IMPORTANT:
When replacing the pump bushing
(003) it is required that the pump seal (002) also be changed at this time. (Figure No. 2)
SERVICE PARTS INFORMATION
Part No.
Description
8623940
THM 400/475 Bushing-Pump Body
8670283
Helixseal Assembly-Oil (optional
with 8670284)
Parts are currently available from GMSPO.
SERVICE MANUAL REFERENCE:
Refer to the Unit Repair section of the appropriate Service Manual for the proper pump bushing and seal replacement procedures.
