rear swinging

[mickeypowa]

Hi guys !!

I have a little problem with my gbody. When I drive at low speed (under 20mph), I can feel the rear of the car swinging left-right.
When I drive on a pothole (there are a lot here !), the rear swings left-right too and It doesn't feel really safe..

I was thinking that it could be the shock absorbers ? I have a pair of brand new rear air shock absorber, maybe I should try them.

What could it be ?

thanks !

 

[lilbowtie]

First thing I would do is check all the swing arm bushings.

 

[L92 OLDS]

Sometimes cheap radial tires with broken bands will cause it. It's only noticeable at low speeds.

 

[lilbowtie]

It would be nice to experience some of these described problems and we would probably put our finger on them.

 

[ck80]

In addition to the above, especially checking all your bushings, what are you running for wheels and tires?

A very narrow rim with a very wide tire, or a very underinflated tire with the sidewall bulging outwards might give somewhat of a sensation like that.

Might be helpful to have someone drive off your rear quarter such as the lane next to you on a 4 lane road and describe what they see while you're feeling the sensation.

Another worst case, but highly unlikely scenario, (also not knowing where you live) I recall in a rust belt state (back when rust issues weren't an inspection criteria) seeing a case where a car was very rusty at the body mount areas... the actual passenger cabin was moving around on the frame, and eventually completely shifted after going around an aggressive corner...

Now, having said all that plus the above, does the location and road surface youre driving on have an effect? Is your low speed driving on rough or unpaved dirt/gravel when you notice it, and higher speed driving on smooth paved when you dont? If you haven't had and/or are a newer owner that's more unfamiliar with these cars, there is a condition called wheelhop that you wouldn't really get driving some Fwd newer car, assuming that is where most of your familiarity is... road surface, particularly potholes, make the rear jump a bit and the rear of the car feels like it's swaying as it relocates

 

[78chevolds]

I am experiencing the same issue and I suspect in my case its the rear control arm bushings are shot. I also get a clunk, not a U joint clunk, from the rear axle when I turn a corner and there is a slight incline.

 

[Bar50]

Also check the front sway bar and end links.

 

[TURNA]

Are your lug nuts loose?

 

[mickeypowa]

First thing I would do is check all the swing arm bushings.

What do you mean by swing arm bushings ? You mean the bushings of the upper and lower control arm ?
Like on this photo : my upper control arm (I guess)


When I bought my car, I had some parts given and I have some bushings from energy suspensions. But I have only 6, how many do I need for upper and lower control arm ?


I have also air shock absorbers like that that maybe I should put on :

Sometimes cheap radial tires with broken bands will cause it. It's only noticeable at low speeds.

A very narrow rim with a very wide tire, or a very underinflated tire with the sidewall bulging outwards might give somewhat of a sensation like that.


Another worst case, but highly unlikely scenario, (also not knowing where you live) I recall in a rust belt state (back when rust issues weren't an inspection criteria) seeing a case where a car was very rusty at the body mount areas... the actual passenger cabin was moving around on the frame, and eventually completely shifted after going around an aggressive corner...

Now, having said all that plus the above, does the location and road surface youre driving on have an effect? Is your low speed driving on rough or unpaved dirt/gravel when you notice it, and higher speed driving on smooth paved when you dont? If you haven't had and/or are a newer owner that's more unfamiliar with these cars, there is a condition called wheelhop that you wouldn't really get driving some Fwd newer car, assuming that is where most of your familiarity is... road surface, particularly potholes, make the rear jump a bit and the rear of the car feels like it's swaying as it relocates

I have mickey thompson sportsman tires, well inflated, with 16" rims, they seem to be in good shape.

https://www.summitracing.com/int/search/product-line/mickey-thompson-sportsman-s-r-tires

Here is a video of the tires rolling, they seem to be OK, no ?

I don't have rust on my car. (almost!)
The problem of swinging happens on a flat road, even with not potholes.

Also check the front sway bar and end links.

What do you mean ? The front stabiliser bar, ball joints and tie rod ends ?

Are your lug nuts loose?

I checked all lug nuts are tight.

 

[TURNA]

The lugs are tight but are the correctly seated all the way down.

You say you have the issue at low speeds. Most issues listed above should be worse at high speeds