strange shimmy

[jg09]

I've noticed a strange shimmy in my car. It doesn't really do it under suspension compression, but when the struts extend, the rear of the car pitches (quite noticeably) to the right. I went to a big high speed dip and hit it at 60 and let me tell you, it was SCARY! I'm thinking bent rear control arm, though I haven't been able to really get under the car and inspect. Remember, this car has been hit and has a rebuilt title, and has a lot of body damage, so I know there's something up with the suspension. It also has all the signs of excessive outer tire wear from bad camber angle. After the accident, the previous owner never bothered to take it into an alignment shop.

[charliekuney]

take it into an alignment shop.

[Sh4d0w]

take it to an alignment shop

+1

[Oldblueaccord]

CHeck your rear upper link for slop at the ball joint or just plain bent. This is what sets your rear camber for most part. Its a high wear item on these cars.

Jack up there car and move the tire at the 12 and 6 o clock posistion.


wp

[markmdz89hatch]

CHeck your rear upper link for slop at the ball joint or just plain bent. This is what sets your rear camber for most part. Its a high wear item on these cars.

Jack up there car and move the tire at the 12 and 6 o clock posistion.


wp

I COMPLETELY agree with this. I'm putting money on the fact your rear upper balljoint is shot. Trust me, of all the rear suspension parts to fail, this is not the one you want. Mine separated on me while going through some downhill twisties (and WAY too fast at that) and hold on because you're in for a ride. ...then a tow. They're cheap and extremely easy to swap. A no-brainer IMO, even if your problem happens not to be this upper rear, I'd still replace it if I were you. Good luck, and please let us know what you find out. ...but please for your own safety and other drivers around you, please correct this. If it's been hit, check out the lower control arm and trailing arm to see if they're bent. If either are bent, they'll cause that shimmy due to the toe being out of whack, and will also eat your tire in no-time.

[jg09]

i'm gonna take it into my suspension mechanic early next week and i'll check out what i can by myself, too. I'll keep everyone updated with how it goes.

[charliekuney]

If I can get the main relay out in under a minute and change the idle control valve by myself, you can probably change part that if Mark says it's easy.

[w261w261]

From my personal history of rear suspension failures:

1. Merritt Parkway (CT) about 1982. Lincoln Continental convertible (a big mutha), going around 65 when a strange but definitely urgent rubbing sound came from the right rear wheel well. Turns out there had been a bearing failure sometime in the car's past, and a new bearing was pressed onto a scored driveshaft. The noise I heard was the wheel rubbing against the fender, as the driveshaft was pulling out of the differential and moving through the bearing. Only the fender being kind of low prevented the entire wheel from coming out and away.

2. Twisty suburban road in CT circa 1986: BMW 3.0CS (coupe). Prev owner had put in Webers, Eibachs, Bilsteins and those very pretty gold wheels favored by 80's BMW owners. A sweet car, and one that would comfortably fly down the Merritt and it's curves at 100. It was only the grace of god that kept me off the Merritt when my rear shock tower's top blew right off. It was bad enough at 35.

Yes, do get that suspension looked at.

[jg09]

fortunately, I sold my Subaru last night for a whopping $300 (not bad for a vehicle that needs a whole new tranny), so I have the money to get it thoroughly inspected. As I mentioned earlier, though, I'm gonna have to wait until next monday or so because the only mechanic in the area that I trust is booked up until then. Hopefully it'll be ok, considering that I'm gonna try and take a mini-road trip in it this weekend.

[jg09]

After checking the car, I really don't think there's any play in any bushings

[markmdz89hatch]

what about the ball-joints?

Have you had a front end alignment done? Are you on stock suspension, or do you have anything aftermarket there (wheels, shocks, springs, etc)?

[Oldblueaccord]

With the tire off the ground your looking for play at the ball joint. The end closest to the tire. Stock its non greaseable and they seem to wear quickly on our cars. Another thing to look at is the wear pattern on the tire itself. Any cupping of the tread esp on the inner edge means there something amiss. Also like you said suspension damage from a crash could cause your rear alignment to be outta spec.

http://img211.imageshack.us/img211/4093/rearlinkwithoutfittinguk0.th.jpg

Other things to check is the condition of the strut and spirng. Broken spring or an oil leak on the strut shaft means its shot.

Sway bar link ends missing or broken, even the front ones, could effect handling and give you oversteer condition.



wp

[cubert]

By shimmy im assuming you mean the car feels like its going left to right, and not hopping up and down?


What sort of shape are the tires in? Bad tires will make the car ride like garbage. How about the axles?

[jg09]

hey, left to right. Right under suspension extension, and it goes left back to center when the suspension levels out. The tires are now newer, and that helped other weird issues on the car, but not this one. The axles are in good shape. The more I think about it, the more it makes sense for it to be a bent control arm

[jg09]

i hate to bump such an old thread, but i finally looked closely at my car. the passenger side rear strut is completely blown, and there's no dampening action at all with it, so that's why the car is pitching strangely.