A/T - THM 200/200C Erratic Shift Patterns

Number 87-7-9 Date 1/87
ERRATIC SHIFT PATTERNS
Subject: DAMAGED/ROLLED GOVERNOR SEALS


ALL 1976-87 MODELS EQUIPPED WITH THM 200/200C TRANSMISSIONS

Figure 1 - THM 200C Transmission I..D. Nameplate:

A 1978 through 1987 vehicle equipped with a THM 200 or THM 200C transmission may have erratic shift patterns (such as late or no upshifts) due to an O-ring seal on the governor cover assembly causing incorrect governor pressure (refer to Figure 1).

NOTE: The erratic shift pattern may be more noticeable after trans reaches normal operating temp.

Figure 2 - Governor Cover Assembly:

Service Action (Refer To Figure 2)

Remove the cover (on car service) and inspect the internal governor cover seal (37). If damaged or rolled, replace the entire governor assembly (36). The seal is not available separately.

Important: Internal governor cover seals must be well lubricated with petrolatum (petroleum jelly) to prevent damage or rolling during installation.

Service Parts Information

8628933 THM 200C Governor Cover Assembly (with seals 35 and 37)

Service Manual Reference

Refer to the Automatic Transmission Unit repair section of the 1987 THM 200C Service Manual for proper installation procedures.