Kimple

More possible causes of vibration:
- Warped hubs
- Out of adjustment or worn wheel bearings

I would check the bearings first. If that doesn't help dial gauge can be used to check wheel hub runout.

Kimmo

coupe

I'll let you all know what the outcome is. My rotors were skimmed recently and braking is very smooth. I think that if your rotors where warped, you would feel it when you brake, and it could even wear down one of the brake pads quickly.

Chris_924s

My vibration (59-67 MPH) was due to a combination of Wheel balance, slightly out of round LF, and a bent PD on the RF- rotate your tires and see what happens..

ACG

<strong>
I drove the car today, and the pulls to the right, and the steering wheel shakes violently from 60 mph to 90.</strong>[/QUOTE]

Hi Coupe, I encountered the same type of problem with my 84 944 last year

A re-alignment corrected the pulling to the right side.

Shaking from 60 - 90 mph definitely sounds like a problem with an unbalanced wheel. My problem was corrected when my wheels got re-weighted.

I don't think it's related to loose wheel bearings, steering rack or tie-rods cos you would have felt the pull to one side or a zig-zagging, or violent shaking from the moment the car starts moving.

coupe

Hello and thanks for all the replies. I have done a search on this forum, and the vibration seems to be a common problem, among these cars.
I'll have to keep looking.

Rod Thomson

Whoda thunk it. I too had the dreaded wobble @ 70 mph. I read the posts figured I would have to get started spending money. Yesterday I had the front wheels off to have a gawk at the struts (need new bumper rubber) and when I took them off i noticed that the locking lug was adjacent to the fill valve. So... I puts them back on with the lock opposite and viola no shake. The weight difference between a locking lug and a regular one must be less than a gram. But you cant argue with success.

85.5 NA
15inch Fuchs

coupe

Rod Thomson...Thanks for that info, I'll that right away and see if it makes any difference.

coupe

Crappola, that quick fix did nothing for me. I'll keep looking...

Mr. Avionics

Was having similar problem, shake from about 60 to 75 Mph. Have replaced both tie rods, one was bad for sure, got the alignment checked, still "shaky jake". This morning I got the tires balanced and swapped front to rear. Voilla! things have smothed right out. Only got to check it up to bout 60-65, rainy morning here, I95 was wet, some damn fool in fast lane slowed down to 50 when the rain started coming down a little faster. Didn't have their lights on and didn't move over. A good place for a wreck to start thats for sure. Well any way, things did get better with a good balance and rotation.
FWIW;
Bill.

Tom Carson

wrong type of locking nuts maybe? do the nuts weigh the same as the others? I had to replace mine with OEMs

I also had to replace 2 of the shops using the balance machines

3rd shop knew what they were doing, machine was calibrated and the car drives perfectly now

Type_LT

How much do you guys think a missing lug would cause a car to vibrate? I just had my tires replaced and I had to drill a lug out because the aluminum nut was on too tight. Upon driving home the shaking is horrible at 70mph, I am of course going to fix it before I drive much but I was amazed that one bolt missing caused that much of an inbalance.

944Play

I've read in more than one place that the early 944 front end "shimmy" is cured by maxing out the caster. I'm not sure how that applies to an '86 951.

mick944

I had a similar shimmy in my 83(non power steer no doubt) except it occured at the 68-69 mph.Before and after that speed were fine and you could drive through it but it would shake your teeth loose if you got stuck in that speed range(rush hr traffic).I went through all the usual suspects.Wheels/new tires balanced on car.New struts/shocks,and alignment.Wheel bearings and tie rod ends were fine.I think the combination of all those things contributed to the vibration and the elimination of it.Now it drives great.Good luck.

phantom309

I had the same problem with Pirelli p6000s. I went to 16" wheels and Dunlop sp8000s and it went away completely. I had the Pirellis balanced multiple times, rotated, etc., nothing helped. Now my car is smooth as glass at any speed.

MAS

This "70 mph shimmy" seems to be a common problem with many 944's. I had an 87 924S that did this, until I put new tires on all four wheels and had them balanced at the same time. The problem vanished for close to a year, when it slowly started to happen again. I had the tires rotated, and the problem got worse. (I've since sold the car)

So I think the 70mph shimmy is perhaps a design flaw that can possibly only be minimized. Poor wheel balancing and/or slighly uneven tire wear problems are probably the most likely causes (or at least make an almost undetactable problem worse).


Incidentally, if anyone's wondering why I think this problem may be a design flaw, it's because I've seen way too many references to the problem over the past decade... and with no one seeming to know the actual cause of the problem.

-MAS