Car shake wobble?

[srq]

I have this car wobble shake at about 52 mph. Took car to a shop for a visual inspection. The front looked OK. Rear had wobble at the ball joints (both sides).

Over last weekend, I replaced both ball joints, and all four control arms (2 on each side) and the two L shaped pieces. I have a separate thread for rear end project.

After redoing the every thing in the rear, I still have that same wobble. It is unlike any car shake I have ever experienced. It is very vicious shake that only exists at about 2 mile around the 52 mph speed. It feels like the whole car is shaking including steering wheel, but is not like a regular front end shake when you have unbalanced wheels. It is a more of a low frequency shake unlike what you get from an unbalanced wheels.

Please note that I have not yet had done alignment after doing the rear end work. Could that be the problem? Or maybe issue w/Drive shaft? Or a bad wheel? Or something else?

Also note that the shake still exists when car is in neutral while rolling at 52 mph. This eliminates issues w/transmission of engine or related mounts.

[shanecarmaster1]

Have you thrown a wheel weight? If not, I'm tuning in to see the solution because I have the same low frequency wobble that I can pretty much hear.

[Shnalla]

Checks the thrust arms.

[Timm]

Viscous wobble is nearly always a stuck caliper on one of the front brakes - more info here:

http://www.meeknet.co.uk/E38/E38_Shimmy.htm

[carnut1947]

Assuming all your wheels are the same offset, switch them front to back. If the wobble changes, worse or better, concentrate on a tire issue. If no change investigate front steering for wear.

[srq]

Viscous wobble is nearly always a stuck caliper on one of the front brakes - more info here:

http://www.meeknet.co.uk/E38/E38_Shimmy.htm

Thanks Timm for feedback. I was thinking about stuck caliper, but in that case, wouldn't tapping the brakes while wobbling would make the wobble go away? It does not.

I will check the front calipers. To test, would a laser thermometer temperature reading on the rotors show a possible fault with stuck calipers? I am guessing that rotor that is possibly stuck should read higher temperature. Yes?

What about wobble caused by the drive shaft. If it were the drive shaft, would putting the car in neutral and let car roll, should this stop the wobble? The drive shaft is still rotating but with no load on it.

[srq]

Checks the thrust arms.

I have replaced all arms in the back last week (including the ball joints). Traction control arms (the bigger ones closer to firewall) in the front were replaced about a year ago. The other two were replaced by PO about 3 years ago. A visual inspection about a week ago did not show any worn parts at the front control arms bushings.

[Timm]

One method of checking if a sticking caliper is the cause of vibration is to drag the brakes for 30 seconds or so (at around 50 MPH) to heat up the brakes - keep off the brakes for a minute or so and then drive through the problem speed. If the vibration has gone you can be sure the caliper is stuck to some extent.

[racer2086]

Definitely get an alignment. Check for a sticking caliper, but my guess is you have something wrong with a tire. How old are your tires? Check the DOT code. Maybe a separated belt in a tire. I hit a bump on an under-construction entrance ramp and immediately got a vicious shake in my car -- like the tire was no longer round. It was real bad between 68-74. Less bad below that and less bad above it.

I had my friend sit in the car and let the car roll in drive with foot off the brake and watched each wheel. Sure enough the left rear would show a hump to the wheel when it passed over the separated belt. I've had that in a couple tires on my car and one in my mom's F10. Those tires were nearly new and the car shook worse than my 7.

I just replaced my front 2 tires because they had flat spots on them which would shake my steering wheel bad at 50 mph. I could see them by jacking the car up and spinning the tire. It was obvious the tire was not round. When taking them off the rim, the dismounting machine went right through the side wall. Apparently because they are old. The new tires are perfectly smooth now.

[srq]

SOLVED Chased this problem for a while. Replaced all control arms,ball joints in the back, checked the front end, cleaned the calipars, ... w/no luck. I already had couple new tires in the back. Decided to also get new tires for the front.
today, the two Continental 235x50x18s came in from Tirerack. Had them mounted and balanced. No more wobble at 50 +-. Have not tested at highway speeds yet but am optimistic (never had noticeable vibration at high speed)

Couple things to note:
The old tires were Dunlop Direzza that were mounted by PO. There was quite a bit of lead weights to balance the old tires (the Dunlops). The new Conti's (both side) did not require any weights for balancing.

I always bought tires from TireRack online and had them mounted/balanced locally. I used my local Tire Kingdom for these jobs. Tire Kingdom no longer mounts tires unless purchased from them (they used to). Called my Sam's Club tire department. Same thing, Sams no longer mounts tires unless purchased from them. I had to find a small Mom & Pop tire place to get the tires mounted.

[jpilk99]

Interesting; glad you see to have figured it out. Only comment I was going to make was to second what TIMM said re a stuck caliper. I had pretty much the same issue. Actually found some play in the passenger front and it was the bushing of the idler arm. I swapped it and figured I was "good to go". I took it on a bigger back road and there was no wobble. YAY; I thought. Then I went up on the hiway and it was still there. My mechanic had an interesting test: After a decent drive, 10 - 15 minutes, hover you hand over the front wheels and make sure it's not cooking hot. As able, touch the wheel - feeling the temp with your hand. Then move to the otherside and do the same. I did this and found the driver's side was ...warm; a normal condition. On passenger's side, it was appreciably hotter (not burning) but hot. Sure enough, when I took the wheel off and removed the caliber, the rubber boot around the piston was shredded and the piston could not retreat.

New caliper, problem solved.

Hope the new tires did it - if not, try that test my mechanic suggested.

Jay