The front suspension rides on the bump stops after driving 200ft, then slowly returns back to normal after 5 minutes...

Here is what I have done

I have successfully done alignments on 3 of my cars in the past, so I decided to get the rx7's alignment into spec. Noticed the driver side front wheel had 2 degrees negative camber but the other side was at 0, also it looked like the drivers side needed caster checked. Front end sat on jack stands for a couple of days as I played with the toe, camber and caster. When I sat the car back down everything looked good. Drove the car on the highway and it did not pull and the steering wheel was straight. "Great!" I thought, but then I pulled off the highway and onto the country road by my house. It was there that the car started bottoming out on the curvy, bumpy road. I got out and noticed that my wheels were completely tucked into the fenders! WTF!!

I drove the car back the short distance to my house in reverse. Sitting in the shop staring at the car, it slowly started to raise back up! After five minutes or so the front was at a normal looking height. I thought that maybe my toe was so out of whack that it was loading up the suspension, rechecked it, and it was less than a 16th of an inch off. I drove the car in reverse to see if it would raise up, but it still ended up bottoming back out.

Car: 102,000 miles, original suspension components, street car, noticed the drivers side is slightly lower than the passengers side I did purchase a lower control arm to try to remedy that.

I have searched, and pondered, but I have never seen anything like this. Can the shocks loose their ability to rebound from having the car jacked up?

Front
Toe: 0
camber: -.5 both sides
caster: ~6 degrees

 

It has already raised up an inch here.

 

You pull the front wheels off and check the springs?


As you alluded to, you may have a problem with one or both of your shocks. You may have to remove the springs and check the moveMent of the shocks.

But at 160,000 miles you may want to look into some updated shocks and springs.


That is definately a weird problem.





John

 

yes, I though that the rubber carrier might have crumbled off of one of the springs, but both look good, and when you set the car back down ride height looks great. If you roll it around ride height is ok, but when you hit a bump driving it does not raise back up! My wallet has a bad feeling about this one !

 

Sounds like your shocks may be locking up.

 

Hmm wonder if it could have been something I did? I removed the lower shock mount on the lower side and nothing was binding with the lower control arm.

 

Yep, something is binding, either the shocks or something in the moving part of the suspension. Shouldn't be too hard to find.

Dale

 

Here is my plan:
1. Remove spindles and shocks
2. Check for binding in control arms
3. Remove springs and test shock absorbers

It just seems strange that this happened after my alignment, but I have redone it, rechecked it, and slept on it many times...

 

Time to get those coil-overs you always wanted.

 

You read my mind

 

From what I understand, this will occasionally happen when an old suspension has been left on a lift for a few days. Crud within the (don't remember the right term but..) valve/sieve within the absorber is blocking free flow. The crud passed through due to full extension and slows down the response until it slowly migrates and settles back to the bottom again.

While the boys over at rx7.com rebuilt my engine they told me that this is a somewhat common problem with older suspensions left on the lift for a few days and something I might prepare for/be aware of. Mine, luckily, was not affected and that I didn't have to worry about it. If I remember correctly, they said it would return to normalcy within a few days, but will be an exceedingly bumpy ride for awhile.

Might not be the same thing, but just passing on what I heard.

 

Thanks for that information, I will drive it around before I tear into it.

 

Update: Pulled the shock out and removed the spring. The shock bounds like you would expect, but no matter what I tried I could not get it to rebound. Even when I hung on it would not budge!

 

my guess is when you adjusted the camber, tightening the cam bolts put tension on the front lower control arm bushings. this would in essence make the suspension very tight and difficult to rebound from bottoming out. try loosening the cams and spray down the bushings with some sort of rubber lubricant like white lithium grease and don't crank them down so tight afterwards.

the rubber bushings do not turn in the control arms, there is a spacer through the center of the bushings that allows them to twist, they could also be very dry.

edit: nevermind, sounds like the shocks are done.

 

When I have the time I might cut into it and see what happened. The piston is still shiny chrome and the car has been in a dry environment.