My '89 Formula feels like it is bottoming out in the rear when I hit a dip in the road. I have new Eibach Prokit springs all the way around. I was told by the previous owner that the Koni shocks are new (put on a few years ago, but not many miles on them). I took a quick look and didn't see any bump stops that I could be hitting.

Could the problem be that the previous owner put on the wrong shocks? Maybe they are too long? Maybe there is another reason this is happening?

I going to be pulling the rear end out due to a gas tank leak and would like to correct this issue at the same time if possible.

Your thoughts will be appreciated.

Thanks,

Chris

 

Is there an adjustment on the shocks? They could be adjustable. If not, they could have blown a seal and could be leaking. Is your car lowered?

 

Thanks for the reply Killer. There's no adjustment on the shocks and my car isn't lowered. The part number on the previous owner's receipts appears to be the correct #. I'm going to see if I can find a number on the actual shocks themselves.

I don't think the car has the original rear end in it. It's got a Borg Warner in it. Could that have something to do with it?

 

The car could have came with the factory borg-warner 9-bolt rear end. I don't think that would cause your problem.

were your new springs the same uncompressed length as your old ones? Does it sit the same now as it did before the install?

A few years on the shocks could still be enough to blow them out. I'd take one off and see how it behaves (if you can simply extend it and compress it then they're shot).

 

Thanks for the reply RedLeader. Car sits about the same height with the new springs as it did with the old ones. I may have to pull the gas tank out in a few weeks to fix a leak and I will check the shocks then.

 

Kxg3

Did you every find the solution to your problem?

 

If they are koni yellows they are adjustable. You have to unbolt the bottom end, fully compress them, and twist because the adjustment is internal. You can search this for better info. Although I don't think adjusting them will help your problem cause the adjustment is for rebound, not compression.

 

Is this right, guys? No bump stops? While having stops might cause things to touch a little sooner, it will be a WHOLE lot softer landing than with none at all. And could save you from some damage to your shocks.

If the car isn't lowered, there is no good reason not to run them, is there?

My all stock '88 T/A WS6 bottoms softly on some of Michigan's terrible roads with passengers in the back. I did not consider this to be abnormal behavior.

 

Hm, yeah there should be some bump stops on there. They may have dry rotted and been bashed away over the years.

 

Haven't gotten to it yet. The shocks are silver an I'm pretty sure they aren't adjustable. I'm hoping to spend some time on it Memorial Day weekend.

I would think if the shocks are bad the rear end would be kind of bouncy. It's not. The springs (Prokit) are new, just had them put in last fall. There is a noticeable thump when I hit a sharp dip in the road. I initially thought maybe it was hitting bump stops that might be to tall, but I don't see any.

 

My bad guys, I said I have Koni shocks when I actually have KYB shocks. I knew that all along. Don't know why I said Koni.

 

I have the pro-kit with Bilstien HD's, They can't control the bouncy, pogo of the pro-kit. The front is fine (linear rate) the rear is a variable rate and kinda light (107 inch-lbs I believe) I don't like how my car handles in the rear with the pro-kit. If you have KYB's that can only make the problem worse IMHO. No where near enough rebound control.

 

Took a quick look tonight. I do have bump stops. Pushed down on the bumper several times and there is no bounce as if the shocks weren't doing there job.