A/T - Harsh Engagement

87pontiac15
Bulletin Number: 88-7-7
Reference Number: 877108

Publish Date: 12/87
HARSH ENGAGEMENT CONDITIONS:
Subject: I. PARK OR NEUTRAL TO DRIVE OR REVERSE II. REVERSE TO DRIVE - VEHICLES WITH 2.8L ENGINES ONLY
Models 1987-88 6000, BONNEVILLE AND GRAND PRIX
Affected: EQUIPPED WITH THM 440-T4 (ME9)

BULLETIN COVERS:

Harsh engagement conditions and specific service information for 1987- 88 models equipped with a THM 440-T4 transaxle.. Other items which cause harsh engagement conditions are:

- vacuum leaks (low vacuum supply to the vacuum modulator) 33-46 Cm Hg (13-18 In Hg) required
- stuck modulator valve
- missing #9 checkball

Figure 1 - THM 440-T4 Transaxle Identification Information:

DATE OF PRODUCTION CHANGE: (Figure 1)

November 24, 1987 (Julian Date 328), all THM 440-T4 transaxles were built using a new 1-2 servo cushion spring, reverse servo cushion spring and reverse servo return spring.

Figure 2 - 1-2 Servo And Reverse Servo Assemblies:

SERVICE ACTION: (Figure 2)

I. Harsh Engagement From Park Or Neutral To Drive Or Reverse - 1988 Bonneville Models

1. Remove the 1-2 servo assembly and the reverse servo assembly from the transaxle.
2. Disassemble and replace the 1-2 servo cushion spring (559) and the reverse servo cushion spring (549) with the correct part listed in the Service Parts Information section.
3. Install the 1-2 servo assembly and reverse servo assembly in the transaxle.

II. Harsh Engagement From Reverse To Drive, Park Or Neutral To Drive
Or Reverse - 1987-88 6000 Models and 1988 Grand Prix Models With
2.8L Engines Only

1. Remove the 1-2 servo assembly and the reverse servo assembly from the transaxle.
2. Disassemble and replace the 1-2 servo cushion spring (559), the reverse servo cushion spring (549) and the reverse servo return spring (552) with the parts listed in the Service Parts Information section.
3. Install the 1-2 servo assembly and reverse servo assembly in the transaxle.
SERVICE PARTS INFORMATION:

Part No. Description Usage

8668121 Reverse Servo Cushion Spring (549) All 1987-88 Models

8668123 1-2 Servo Cushion Spring (559) All 1987-88 Models

8668127 Reverse Servo Return Spring (552) 1987-88 Vehicles W/
2.8L Engines Only

SERVICE MANUAL REFERENCE:

Refer to the THM 440-T4 (ME9) Automatic Transaxle On Car Service section for appropriate service information.

SERVICE NOTES:

For warranty purposes, use both Labor Operations described below:

Labor Operation K6623 for the reverse servo assembly:

1987-1988 6000 Models - .5 Hour 1987-1988 Bonneville Models - .8 Hour 1988 Grand Prix Models - .8 Hour

Labor Operation K6626 for the 1-2 servo assembly:

1987-1988 6000, Bonneville Models - .5 Hour 1988 Grand Prix Models - 2.1 Hours