Front suspension clunk

[RichardH]

1989 Buick Regal

There's a clunking noise coming from the general area of the right front wheel when I drove over bumps. I can't reproduce this noise by, e.g., jacking it up and releasing the jack suddenly.

I replaced the front struts (shocks), but that didn't make any difference. One thing that was very obvious, however, was that the top of the right front strut tower moved forward as soon as I pulled the strut out of the tower. I had to forced the tower back into position to replace the strut. The left front strut tower, on the other hand, stayed centered above the wheel just like the manual said it would.

I'm thinking that the right front ball joint is bad, but I don't see anything abviously wrong with it. I can't rock the wheel back and forth, top to bottom, when it's jacked up, for example. The general disposition of the ball joints on each side look the same and the ball joint boot isn't split. There's nothing visibly wrong with the suspension. There's no irregular tire wear.

Has anyone encountered this before? Is it likely to be the ball joint even though there's nothing visibly wrong with it?

Thanks for any tips,

Richard

[Roadmonster]

There are only 2 things that come to mind. 1) The strut top may be bad. Between the plate where the 3 studs come up through the fender and the plate where the top of the coil rests. Thats the area that allows the strut to pivot when turning the steering wheel. If it becomes seporated the strut will knock up and down slightly when going over bumps. 2) would be bad struts (although already replaced) if they are not obviously leaking they may have lost their pressure. Only way to check for sure is to remove them, seporate them from the spring and try to push the piston down by hand. I have seen struts were only the top 1 or 2 inches of the piston stroke is dead with no pressure. The rest of the downward stroke had pressure. That would give you a clunking noise when going over bumps but not when bouncing the car to recreate the noise in park.
I have rarely seen a bad lower ball joint on a front wheel drive car.
Good Luck

[RichardH]

Thanks for your thoughts. I didn't notice anything wrong with the strut top when I replaced the strut, however, and the noise was also present with the old strut, although it wasn't as bad. I think it's getting worse with time though.

Why would the top of the strut tower on the bad (noisy) side be disposed to moving forward as soon as the top of the strut assembly is released? There's so much tension on the coil, with the car sitting on its wheels, that I had to use another car to pull the strut tower back so that I could drop the new strut in.

There seem to be only two things that could explain this. Either the coil is bad (but it looks okay), or the lower pivot point, the ball joint, is bad.

I think it's suprising that the coil should stay centered when you remove the top of the strut mount (which is the normal way to replace the strut). I'm guessing that the movement is somewhat constrained by the ball joint.

That's why I was thinking it must be the ball joint/control arm, even though I can't see anything obviously wrong with it.

[Roadmonster]

Well, if the lower control arm bushings and sway bar bushings are OK. Then change the ball joint.
Something else to try - try spraying the bushings with a heavy duty oil, like auto transmission fluid. Coat them up good and take it for a ride. See if the noise changes. Are there grease nipples on the ball joint and tie-rod end? If there are no grease nipples, put a small pin hole in the rubber boot on ball joint then fill the boot with trans fluid and drive it. If the noise is gone, at least you know it was the ball joint that is dried up. It's up to you if you still want to change it.

[RichardH]

That's a good idea -- thanks.

[Roadmonster]

How did you make out? Did you find the cause of the clunk?

[RichardH]

How did you make out? Did you find the cause of the clunk?

I haven't made any progress yet, although I did purchase a pair of replacement ball joints. Nevertheless I think I'll try the test you suggested before going to the trouble of swapping them.

I'll let you know what I find.

Thanks for checking in with me.

Richard

[RichardH]

Did you find the cause of the clunk?

I finally sussed it out. When I replaced the front struts the passenger side one was really a struggle since the coil didn't stay stright, but instead shot forwards as soon as I removed the strut. I had to use my 4x4, with a rope, to move the strut tower backwards while a friend used another rope to pull the strut towards the middle of the vehicle.

The upshot of all this struggling was that I was so happy even to be able to get the strut back that I didn't tighten it down all the way.

When I jacked up the passenger side of the vehicle and pulled up the concertina strut protective boot there were three threads exposed where the strut screws into the strut tower. Uaing a spanner wrench in between the coils on the spring I was able to use opposing holes on top of the strut (where you would normall engage the 4 pins of the GM strut tool) to screw the strut all the way in. This completely cured the clunking.

Does this make sense? It's much easier, and more effective, to use a spanner wrench in from the side to tighten the strut than it is to use the GM tool from the top.

[Roadmonster]

so they were replacement pistons, not the whole strut? If the the nut was not tightened down all the way that would do it. Another trick is to put alittle oil into the strut tube when replacing the piston. It helps to dampen any noise. Glad you found it. I'm still unsure why you had such a problem realigning the strut back into the wheel well. Something must be bent on that side. Screw it, drive till the wheels fall off!!!

[RichardH]

so they were replacement pistons, not the whole strut? If the the nut was not tightened down all the way that would do it. Another trick is to put alittle oil into the strut tube when replacing the piston. It helps to dampen any noise. Glad you found it. I'm still unsure why you had such a problem realigning the strut back into the wheel well. Something must be bent on that side. Screw it, drive till the wheels fall off!!!

Correct. The old pistons were bad and it was making the same clunking noise prior to replacement, although not as badly (when I look back on it). I did put the oil in there.

So long as the wheel doesn't fall off on the highway! Drive it until the engine or tranny fails, was more along the lines that I was thinking.

I replaced the head gasket a couple of years ago. This has a very thin spot in the front, driver-side corner that looks designed to fail. It's been running like a champ ever since. Excellent, consistent compression on all six cylinders and very good highway fuel economy. It's been in our family since new so it's been well cared for.

Thanks for your input/help!