Grand Prix V6-191 3.1L (1989)
Seals and Gaskets: By Symptom
Technical Service Bulletin # 8978
Date: 881101
A/T - Intermittent Slip In Forward/Reverse When Cold
Bulletin Number:
89-7-8
Reference Number:
877150
Publish Date:
11/88
Subject:
INTERMITTENT SLIP IN FORWARD AND/OR REVERSE WHEN COLD
Models
1989 6000, BONNEVILLE AND GRAND PRIX
Affected:
EQUIPPED WITH THM 440-T4/HMD 4T60
FIGURE 1 - THM 440-T4/THM F-7 TRANSAXLE IDENTIFICATION INFORMATION
BULLETIN COVERS:
An intermittent slip in forward and/or reverse when the transaxle is cold may be caused by leaking Input Shaft Oil Seal Ring(s) (624). This may be due to
one or more undersized Input Shaft Oil Seal Ring(s) that seal the Input Clutch and 3rd Clutch feed holes. The transaxle may slip less in Reverse or
Manual Lo (D1) ranges (due to boosted line pressure) than in Overdrive (D4), Drive (D3), or Manual Second (D2).
FIGURE 2 - INPUT SHAFT OIL SEAL RINGS
SERVICE ACTION: (Figure 2)
Disassemble the transaxle, remove the Shaft and Housing Assembly (626) and inspect the Input Shaft Oil Seal Rings (624) while in the grooves. The
rings should take up most of the groove width. If the ring (s) only takes up about half of the groove width then replace them with rings from the package
