A/T - THM 440-T4 Slip or No Drive
Bulletin 87-7440-6Date Apr. '87
Ref. No. 87-102-7440
Corp. Ref. No. 717104R
SUBJECT: SLIP OR NO DRIVE, THM 440-T4 (ME9)
MODELS AFFECTED: 1987 CENTURYS, ELECTRAS, LESABRES AND RIVIERAS
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.
FIGURE 1 - THM 440-T4 TRANSAXLE IDENTIFICATION INFORMATION:
DATE OF PRODUCTION - (Figure 1)
THM 440-T4 transaxles 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. Replace the oil pump assembly to repair this condition.
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 Buick Chassis Service Manual.