83 cab - side to side shake

[SCWDP911]

Has anyone ever had this symptom before:

Sometimes when I drive the car up at 50+ mph, I will get this side to side shake that can be felt through the steering wheel. Last night I played around with it a little while driving - it seemed like it might diminish a little if I let up on the accelerator, but not much. Then, it will go away. I THINK I am noticing it start when I hit a bump in the road, then it tends to settle out a bit like I mentioned earlier.

I have had the car up on a rack twice with the front wheels off and cannot find anything loose in the rotors, shocks, or other obvious suspension equipment I can think of. It has to be something. My thought now has turned to maybe one (or more) bad engine/tranny mounts.

Anyone ever dealt with this. I hope someone can understand what I am feebly trying to describe - it is kind of tough to describe in words...

Thanks,
Shane

[kqw]

Is the "shaking" you describe somewhat violent or sort of a squishy type shake?

[toddu]

Visually, what shape are you ball joints in (rubber still intact, grease not comming out, etc)?

Have you had your tires balanced lately? I had my tires rebalanced at a very good shop, and it turns out my rear tires are not completely round. While driving, this translates into a rear end shimmy.

Todd

[SCWDP911]

The shake is more rough than squishy, but not sure I would call it violent. As I was checking things out yesterday, I noticed if I took my hands off the steering wheel for a few seconds during a time of shaking, the wheel was going back and forth with the shake (CW-CCW-CW-CCW, etc).

I have not looked at the ball joints yet. I just had the tires rebalanced, and thought that might be it when they told me they were off. However, it is still doing it.

[kplackmeyer]

Check your wheel bearings for any play. They can make the front end shake if they are bad. And make sure you didn't throw a weight after the new wheel balance job.

[sean m]

This may or may not be the cause...
I had a car that in an emergency I used "fix a flat" on a tire that took a nail. At 50 mph got the same shake you've got. I thought I just needed to get the tires balanced.

Boy was I wrong....that stuff ruins tires.

Sean

[SCWDP911]

Originally Posted by kplackmeyer

Check your wheel bearings for any play. They can make the front end shake if they are bad. And make sure you didn't throw a weight after the new wheel balance job.

Yeah, I wondered about that, but put it in the back of list because I watched the guy hammer them on. As far the wheels bearings, if I cannot move them by my own physical strength with the car in the air, wouldn't that qualify as OK?

[kplackmeyer]

Originally Posted by v8_ranch

Yeah, I wondered about that, but put it in the back of list because I watched the guy hammer them on. As far the wheels bearings, if I cannot move them by my own physical strength with the car in the air, wouldn't that qualify as OK?

Yeah, bearings prob ok. Make sure you grab the top & bottom of the wheel to check them..not sides.

As far as the weights are concerned, I always have shops use stick-on weights as not to damage the wheels. Clean surface with lacquer thinner or similar first to make sure they stick. Less likely to fly off, too. Not sure what wheels you are running, so maybe the hammer-ons are ok.

You can also find a shop that will balance the wheels ON the car. If you have locking lugs, they can weigh differently than the other lugs and that can throw it off, as can the rotor and hub.

Finally, you might have a bad tire. If the shop didn't look closely, you might have some lateral variations in the tire, which won't show up on the balance, but will at the steering wheel.

[toddu]

The shop I had my tires balanced at had a tire balance machine that I guess is not the norm. It is able to test the "roundness" of the tire by putting load on it and taking measurement. There is some exceptable range (15 sticks in my head, but not sure what that's measured in), and my Khumo's were like 50+. He said "the tires are balanced, but you might feel some movement in the back at speed"... I sure due. It's some what random, sort of varies in "strength".

If it were in the front, I would expect it to show up in the steering wheel.

My steering wheel did shimmy, but I replaced my whole front (tie rods, ball joints, bushings, etc), and then did the tire balance, so not sure what all fixed it. The ball joints were definetly shot though.

Todd

[450knotOffice]

alignment possibly.