A/T - THM 440-T4 Slips or No Drive

87olds3

SUBJECT 1987 THM 440-T4 SLIP OR NO DRIVE NUMBER: 87-T-19


DATE: April 30, 1987


MODELS/YEARS 1987 CUTLASS CIERA, DELTA 88,
SECTION: 7A
NINETY-EIGHT AND TORONADO MODELS
BULLETIN COVERS:

A slip or no drive condition on a THM 440-T4 transaxle may be caused by low line pressure due to the pump slide binding on excessive casting flash when the slide is in the low pressure position. Modulator vacuum will not affect line pressures if this condition is present. This condition can be repaired by replacing the oil pump assembly.

FIGURE 1 - THM 440-T4 TRANSAXLE IDENTIFICATION INFORMATION:

DATE OF PRODUCTION: (FIGURE 1)

A THM 440-T4 transaxle built between November 26, 1986 (Julian Date 330) and January 12, 1987 (Julian Date 012) may exhibit this condition.

FIGURE 2:

SERVICE ACTION: (FIGURE 2)

Remove oil pump cover and pump priming springs and move the slide by hand. If excessive flash is present, the slide will bind in the area indicated in Figure 2.
SERVICE PARTS INFORMATION:

Refer to GMSPO catalog for part number information.

SERVICE MANUAL REFERENCE:

Refer to THM 440-T4 (ME9) Automatic Transaxle Unit Repair for oil pump service information in the 1987 Chassis Service Manual.