Rear suspension issue...

[Reaper1]

Today I discovered I have an interesting rear suspension issue. Now, keep in mind that I haven't had a chance to really take a good look at it yet, but I can describe the issue and I'd like some feedback on where to look for potential problems.

First, my rear suspensionset-up: Koni shocks, Eibach springs, stock '88 Shelby Z axle, CS Racer panhard bar with heim joint ends, 11" brakes.

The issue is that if you push the car from the side fairly harshly(like what would be happening in a fast transition ala slalom or emergency lane change) you can hear a "clunk"(almost sounds like the exhaust is hitting, but it's definatly NOT) and also watch the camber of the tires move slightly, much like if the preload on the wheel bearings in the hubs were not set propperly(which I DID check and they are fine). This is while the car is sitting on its own weight on the ground.

My first suspect is that possibly the heim joints on my panhard bar have taken a crap. Now, they are less than a year old, so I HOPE this is not the case. With the car sitting on the ground I can get under there and grab the bar and try to move it, but the only thing it does is turn. I can't get it to move like if the joints were bad. Now, I haven't tried this with the suspension unloaded yet.

So, I'm kind of at a loss as to what could be causing this problem. The only things that control the latteral movement of the rear axle is the panhard bar, and the mount for it on the driver's sid eof the car that bolts to the body. The trailing arms "do" provide some control, but the bushings allow some slop. I wonder if I destroyed one of those due to my recent track outings? Could that cause this issue even if the panhard rod is doing its job correctly?

Thanks for any suggestions that anybody may have. I'd like to get this thing taken care of before it causes a real problem!

[BadAssPerformance]

Yep, wheel bearings and/or panhard rod ends sounds like it, but since you said the camber appears to change, also check the bolts holding the spindle assemblies to the axle.

[turbovanman²]

I would check the wheel bearings, heim joints-if you drive in the winter etc, they could be worn out, and the driver side mount for the panhard bar, it could be cracked or come loose.

[BadAssPerformance]

Yeah, I thought winter till I remembered that Reaper1 is is FL!

Always good to re-check wheel bearings.. and by re-check, I mean re-grease and re-set bearing preload!

[turbovanman²]

Yeah, I thought winter till I remembered that Reaper1 is is FL!

Always good to re-check wheel bearings.. and by re-check, I mean re-grease and re-set bearing preload!

Nice catch, damn Floridians,

[BadAssPerformance]

Yeah, unless he lives on the coast, or drove it on the beach, its prolly clean....

[Reaper1]

I have driven *next* to the beach(kinda hard to NOT do that around Daytona Beach, LOL), but the car has NEVER been on the actual beach, at least not in my ownership, and certainly not since I've had the panhard bar on it.

I'll definatly check the bolts for the panhard mount as I did have them loose when I installed the bar, and I *think* I had them loose when I did the exhaust.

I'll probably repack the wheel bearings as they are more than likely due and while I have the hubs off I can check the spindle bolts.

I will say that I can try to shake the individual tires to check the bearing preload, and that is fine. It seems like it is the entire axle shifting....

I suppose I have some work ahead of me. It's a never ending story....lol

[Vigo]

honestly.. all my k-cars have done this. It was a pain to get my cars through tech at AutoX because of it. Not saying it cant be fixed tho..

[Johnny]

honestly.. all my k-cars have done this

They should never do this!!

Check what they said above!

Johnny

[Reaper1]

Johnny, do you have any more ideas of things that could cause this?

[Johnny]

I'd just check the obvious :
bad bushings in track bar and where the axle arms connect to the body bracket
The heim joint ends in place of bushings could go bad
loose bolts/broken welds on track bar or mounting points/brackets
I have see track bars bent, could be bending
and as above...
wheel bearings, hub bolts.

You need to have someone with good eyes looking while someone else
produces the movement you say you are having.
Johnny

[Reaper1]

I'd just check the obvious :
bad bushings in track bar and where the axle arms connect to the body bracket
The heim joint ends in place of bushings could go bad
loose bolts/broken welds on track bar or mounting points/brackets
I have see track bars bent, could be bending
and as above...
wheel bearings, hub bolts.

You need to have someone with good eyes looking while someone else
produces the movement you say you are having.
Johnny

Yeah, I was wanting to get my room mate to push on the car while I looked under it.

The track bar is a CS Racer tubular unit with heim joints. If that thing bent...just wow . I keep leaning toward the heims going bad or the bolts that hold the track bar mount on the driver's side being loose. I've had a rattle coming from over there for a bit, but I never thought of that as being the source.... Time to really check it out now!

[Vigo]

ok well i guess i'll actually contribute.

put on the parking brake. if it doesnt make the noise, its in the brakes/bearings.

mine would stop making the noise if the parking brake was on, but as you said the bearings always looked/felt fine when checking the wheel for play and i never got it to stop making the noise even though i repacked / preloaded the bearings a few times for various reasons.

of course you cant go through tech with your parking brake on.. i tried. several times. lol Never once had a bearing problem in the rear, either. Just a noise that only tech inspectors care about.

[Johnny]

If the wheel bearings make noise when the push in and out on the tire, like they do in tech, they are too loose. I have had that happen to me before also.

Johnny

[black86glhs]

Double check the shocks and all that hardware.

[Reaper1]

I can grab the rear wheels with the brake off and try to shake it in and out(like trying to change the camber), and there is no significant movement(like something being extremely loose), and there is no noise that sounds like what happens if you shake the entire car.

Odd thing, the tech inspectors never checked my wheel bearings(which I have had them do before), and I even got an anual tech pass the other day! LOL

I'm going to jack the rear of the car up with the tires off, set it on jack stands, take the springs out, put the shocks back on, then use my jack to put the axle at "ride height" so I can look at stuff as it sits in the car without the springs preloading it. That should make it easier to find the issue....I think...

[Murphy]

my car did this - stock 91 spirit rear axle, daytona shelby springs, KYB Gas-A-Just, CS racer panhard bar. I drove with that noise for about 2 years

[Reaper1]

Well, I dont' like noises from my suspension, track inspectors don't like them either. Plus, if it IS changing my suspension geometry while I'm trying to do extreme manuvers with the car, it is making it unpredictable and not helping me learn how to drive the car effectively at all!

In other words...I HAVE to fix this!! LOL

[Vigo]

Plus, if it IS changing my suspension geometry while I'm trying to do extreme manuvers with the car, it is making it unpredictable and not helping me learn how to drive the car effectively at all!

Best ad for an upgraded track bar ever written.

[Reaper1]

That's the thing, I've GOT one on there! LOL

I'm just hoping the heim joints haven't gone out on me. The car is 90% street car, and heims aren't the best thing in that application. I had planned to get the dust covers for them before I installed the bar, but the installation happened sure-of-the-moment, and I simply "forgot" about it...