GROUP: Automatic Transmission
SUBJECT: Thumping Noise
MODELS: All Models Equipped With Borg-Warner 35 Transmission
Some cases of a thumping noise from the transmission have been reported when shifting into ‘D’ or ‘D1’. If you should encounter this, the following action is recommended:
- Be sure that engine idling speed is correct and that the throttle is not sticking.
- Check and adjust if necessary, downshift cable using a pressure gauge and tachometer. See WSM 139, Part 1, pages 8, 9 and 10.
- Remove transmission pan and valve block. Be sure that the following valves are free to operate and are not sticking:
- throttle valve
- primary regulator valve
- modulator valve
- Fit replacement 1st/2nd shift valve spring, part number 5039919.
- Re-fit valve block and pan. Re-fill with oil and road test as per WSM 139, Part 3, page 4.
Manager – Service & Parts