MODELS: All Models Equipped With Borg-Warner 35 Transmission
SUBJECT: Thumping Noise

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:

1. Be sure that engine idling speed is correct and that the throttle is not sticking.

2. Check and adjust if necessary, downshift cable using a pressure gauge and tachometer. See WSM 139, Part 1, pages 8, 9 and 10.

3. Remove transmission pan and valve block. Be sure that the following valves are free to operate and are not sticking:
   • a. throttle valve

   • b. primary regulator valve

   • c. modulator valve

4. Fit replacement 1st/2nd shift valve spring, part number 5039919.

5. Re-fit valve block and pan. Re-fill with oil and road test as per WSM 139, Part 3, page 4.

T.H. Bullard
Manager - Service & Parts