LeSabre V6-231 3.8L VIN A 2-bbl (1984)
Shift Modulator: All Technical Service Bulletins
A/T - Harsh Engagement Neutral to Reverse
Bulletin
87-7440-1
Date
Nov.1 '86
Ref. No.
87-018-7440
SUBJECT:
HARSH NEUTRAL TO REVERSE, NEUTRAL TO DRIVE PARK TO REVERSE, PARK TO DRIVE AND/OR TRANSMISSION SLIPPAGE
MODELS AFFECTED: 1984-87 CENTURYS, ELECTRAS, LESABRES AND RIVIERAS EQUIPPED WITH 3.8L V-6 ENGINES (VIN CODES B &
Some THM 440-T4 transaxles may exhibit harsh Neutral to Reverse, Neutral to Drive, Park to Reverse, Park to Drive, and/or transmission slippage.
These conditions may be caused by a plugged vacuum tube from the engine to the transmission modulator.
When servicing any THM 440-T4 for this condition, remove the vacuum tube and inspect for any obstructions. Especially check for a thin coat of paint
at the engine end of the pipe. Remove any foreign material so that the inner diameter of the pipe is completely open. This should be done prior to any
disassembly of the transmission for corrective repairs.
