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

Bulletin No. T 87-88
File in Group 7
Number 159
Corp. Ref. No. 717104
Date April '87
SUBJECT: THM 440-T4 - SLIP OR NO DRIVE

MODELS AFFECTED: 1987 DE VILLE, ELDORADO AND SEVILLE

Some 1987 440-T4 transaxles built between November 26, 1986 (Julian Date 330) and January 12, 1987 (Julian Date 012), may exhibit a slip or no drive condition as a result of low line pressure.

This condition may be caused by the pump slide binding on excessive casting flash when the slide is in the low pressure position.

To verify the possibility of a binding pump slide, check line pressure while the vacuum signal line is removed and reinstalled on the modulator fitting. If normal (minimum/maximum) pressures are recorded, proceed with the usual diagnostic steps for the cause of low line pressure.

If pressures do not vary with vacuum signal changes, inspect for pump slide bind by removing the oil pump cover and rotating the slide by hand. If present, excessive flash will cause the slide to bind. If found, replace the oil pump assembly.

Refer to the appropriate Service Information Manual index for oil pump replacement procedures.

For warranty purposes, use K6570 for 3.3 hours on De Ville/Fleetwood and 3.8 hours on Eldorado and Seville.