I have a 1993 940 Turbo, automatic, with about 125,000 miles on it. It's been running great...no problems most of the time. However, whenever I have a lot of people in my car (4 or 5 including myself), the whole car shakes when accelerating from rest. Once it gets past about 15 miles an hour, it's fine, but when I'm accelerating from a stop the car shakes as it gets going. If I accelerate very slowly, it seems to help. My transmission fluid seems to be okay.

Any ideas?

Sounds like the known problem of drive shaft shudder. Here's a link to the TSB and more information.

Good luck.

Robert

Awesome. Thanks so much.

Dave

Robert,

What does one use to shim the center support bearing?

Thanks in advance.

Jeff Pierce
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

I experimented and shimmed mine both up and down looking for the "sweet spot" where the drive shaft shudder stopped. As I recall, the support bearing is mounted to a bracket that in turn is mounted to another bracket in such a way that they can be shimmed either up or down depending on where you put the washers. Once you get access to the underside of the car, it's pretty easy to do.

I went to the local hardware store and bought a handful of washers. It seems like they were around three eights or seven sixteenths in size to allow the bolts to fit, but it's been awhile. When you look at the mounting, you'll be able to tell the size pretty easily.

Robert

Great, thanks.

Jeff
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

A washer.
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90 744ti, Airbox, K/N, Cold air, G-Valve, Dual boost control, VDO, Modified exhaust. 88 745 gle, 99 Camry

Has the transmission tailshaft bushing been replaced? Seems a bit early for it to fail, but it's possible. If there's any play at the output flange of the transmission then it's time. More likely it's a driveshaft issue - center bearing support, u-joint, or center bearing alignment - I recall there being a Volvo TSB about shimming the center bearing support crossmember, though I think it was for 960s. Also check for a weak/failed motor mount. At one time or another I've had each of these cause shuddering or vibration at slow speed in my 240/740s.
-Chris