A/T - THM 440-T4 Long/Delayed 2-3 Shift
87buick9Bulletin: 87-7440-5A
Date: Oct., 87
Ref. No. 87-072A-7440
Corp Ref. No. 777131R
SUBJECT: THM 440-T4 NEW 3RD CLUTCH INNER SEAL REPLACEMENT FOR A LONG AND/OR DELAYED 2-3 SHIFT CONDITION
MODELS AFFECTED: 1984-87 THM 440-T4 TRANSAXLES
FIGURE 1:
NOTICE: This bulletin contains updated Julian date breakpoints and supersedes Dealer Bulletin 87-7440-5 which should be discarded.
A long and/or delayed 2-3 shift on a THM 440-T4 transaxle may be caused by a leaking 3rd clutch inner seal (Figure 1, Item 635A). A new thicker seal is used in production and available for service replacement. The new seal can be recognized by a small group of hash marks on the inside diameter of the seal.
DATE OF PRODUCTION CHANGE
Between September 1, 1986 (Julian Date 244) and February 12, 1987 (Julian Date 043), a new 3rd clutch inner seal was phased into production. This change is also on all Service Replacement Transmission Assembly (SRTA) models, effective November 15, 1986 (Julian Date 319).
SERVICE ACTION IF THIS CONDITION IS ENCOUNTERED
Remove transaxle, disassemble, inspect and replace with parts in the following service package:
Package Number Description
8646991 - Housing and shaft assembly, input
- Seal, 3rd Clutch Inner
- 3rd Roller Clutch Assembly
To service 1987 models built with the new seal design, use seal kit only, (input and 3rd clutch, Part Number 8644919) which contains the new thicker seal.
The new thicker seal in the kit, Part Number 8644919, may also be used to service models built prior to the above Julian dates, provided a long or delayed 2-3 shift condition has not occurred and the third clutch inner seal is not found to be damaged upon unit assembly.
FIGURE 2:
SERVICE MANUAL REFERENCE
Refer to the THM 440-T4 (ME9) automatic transaxle section of contents for 3rd clutch service information.
Long And/Or Delayed 2-3 Shift