One Piece Channel Plate Gasket

FIGURE 11 - MODULATOR PORT AND CHANNEL PLATE (UPPER) GASKET:

TRANSAXLE APPLICATIONS: SUBJECT:

1989 THM 440-T4 (ME9)
1989 THM F-7 (ME9) One Piece channel Plate Gasket

TRANSAXLE MODELS: VEHICLE APPLICATIONS:
All THM 440-T4
THM F-7 - AXH A, C, H, E, K, W, Z Cars
V Cars

CHANGE TO ASSEMBLY COMPONENTS: (Figure 11)

A new one piece channel plate (upper) gasket (801) is used to replace the channel plate plate (upper) gasket (409) and modulator port gasket (415). The one piece design ensures that the gasket does not become mispositioned upon assembly of the channel plate.

SERVICE ACTION:

When servicing a past model (built after 1985-1/2) use the new one piece channel plate (upper) gasket. The one piece channel plate (upper) gasket will service all past models back to 1985-1/2. Transaxles built before 1985-1/2 must still use the two piece channel plate gasket.

IMPORTANT:

The new one piece channel plate gasket cannot be used to service transaxles built before Julian Date 011 for 1985 models. If the new gasket is used on a previous channel plate, park, reverse and neutral (PRN) fluid may enter the reverse servo feed circuit and apply the reverse band. Since the input clutch is applied in Park, the transaxle may be in Park and Reverse at the same time when Park is selected.

SERVICE PARTS INFORMATION:

Part No. Description Model Year - Model Usage

8646945 Gasket, Channel Plate 1985-1/2-89 - All
(one piece upper/lower)
8646908 Gasket, Channel Plate 1984-85-1/2 - All
(two piece upper/lower)

Parts are currently available from GMSPO.

SERVICE MANUAL REFERENCE:

This product change information is shown in the THM 440-T4 and THM F-7 Automatic Transaxle Unit Repair section of the 1989 Service Manual.

SERVICE NOTES:

This change was implemented into some models late in the 1988 model year.