Help!
If I come to a hard stop and then try to normally accelerate I get a vicious shuttering coming from under the hump (shift selector). If I then back off the accelerator it seems to pop back to normal. This doesn't happen if I come to a softer stop. I have a '87 740 (non-turbo) ZF trans. I had my mechanic look at the U-joints, center-support, etc with no luck. This doesn't happen every time but has been going on for a very long time and is beginning to frustrate me. The car is in fabulous shape otherwise. Any suggestions?

I agree with JS about the tranny mount. Sounds like your hard stop "sets" the running gear in a precarious position. If it was the center bearing needing shimming, I would THINK your symptoms would be more consistant, no matter what the stop was like.

This problem is addressed in the FAQ, reprinted below for your enjoyment. I was having the exact same problem. I shimmed it up 1/4" and that cured it. Note: I had to use longer bolts to get proper thread engagement.

"Driveline Take-Off Vibration: Shimming May Be Required. From Volvo Technical Service Bulletin 45/102 Jan '91. [Symptom:] Take-off vibrations at low speed, especially with high acceleration and/or heavy load, can occur in some cases. [Solution:] The level of vibration can be reduced by changing the vertical position of the center support bearing. Best results differ from car to car. Start with a change of 6mm (1/4") upwards. If results are not acceptable, try positions from 5mm (3/16") downwards to 12mm (1/2") upwards from the original position. Note that clearance between drive shaft and fuel lines must be at least 20mm, and between drive shaft and the fuel tank at least 16mm. Shimming upwards should not exceed 12mm (1/2") and after re-positioning the center support bearing housing should not contact the floor pan."


bagle 745t, aw71

Check the tranny mount. This among many other weird things were happening on my 740. Took the tranny mount off and it literally fell apart. Fixed numerous problems and the drive totally different.

Thanks all you guys for the info. I remember reading about the shimming but did not think it would apply to me. The mount looked ok, but now I'll take it off just to be sure. If that doesn't work I'll try the shimming.
PS: This board is GREAT.