A/T - New Servo Apply Pin

87chevy18
GMC NUMBER: 88-T-44

GROUP: 7A - Automatic Transmission

DATE: September, 1987

CORPORATE
NUMBER: 867105
SUBJECT: NEW SERVO APPLY PIN

MODELS: 1982 - 88 LIGHT DUTY MODELS EQUIPPED WITH THM 700-R4 AUTOMATIC

TRANSMISSIONS
BULLETIN COVERS:

This bulletin covers changes to the second servo apply pin that eliminated the two ring seals. This change reduces the potential for seal damage during assembly. Testing has shown that any potential leakage in this area with the new design pin will not affect transmission performance.

FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION:

FIGURE 2:

DATE OF PRODUCTION CHANGE:
(Figure No. 1)

Beginning January 5, 1987 (Julian date 005) THM 700-R4 transmissions were built with the new servo apply pin (Figure No. 2).

SERVICE ACTION:

The new second servo apply piston pin (Figure No. 2) can be used on all 1982-1988 THM 700-R4 transmissions.
NOTICE: If a past design second servo apply pin is used on a THM 700-R4 transmission, seal rings must be installed.

SERVICE PARTS INFORMATION:

SECOND SERVO APPLY PIN
PART
NUMBER DESCRIPTION PIN LENGTH

8667571 Pin Second Apply 66.37-66.67 mm (2.61" - 2.62")
(2 IDENTIFICATION RINGS)
8667572 Pin Second Apply 66.74-68.04 mm (2.67" - 2.68")
(3 IDENTIFICATION RINGS)
8667573 Pin Second Apply 69.11 -69.41 mm (2.72" - 2.73")
(WIDE BAND)