So a couple weekends ago I installed some custom springs. Afterwards I noticed that anytime I am in 2nd or 3rd gear I feel a shaking sensation that seems to come from the rear end, and only in the 2-3k rpm range. I have had tires balanced and new tires installed and this didn't fix the problem. It seems to be coming from the rear end, and as anyone that has installed springs in the rear, it's pretty easy and idiot proof. I still have the stock shocks and they are in good shape still. I could always swap the stock ones back in, but I'm wondering if this could be something else since it's only happening in a certain gear and RPM range? Maybe it's not related to my install -- maybe tranny mount? I've upgraded engine tranny mounts a while back though.

Thoughts?

 

You did get an alignment after putting the springs on, right?

 

Of course....alignment was in spec. Caster was a little off -- and I found out there really is no way of adjusting caster on our cars. Nice.

 

So bump back to this since it's still happening -- I'm wondering if this could be a bad wheel bearing in the rear? Maybe I did something installing the springs? It's still only happing at certain RPM's....whether turning or not doesn't matter. I checked my upgraded engine mount and transmission bushing.....they are fine. I'm kind of stumped even after upgrading rotors/pads/shocks/springs over the past month getting this thing track ready. My only thought is it's either my springs or the bearings. I jacked the car up and no movement, but that doesn't necessarily mean anything.

 

Spring brand? How big of a drop? Are the upgraded tranny mounts just inserts only? Are the top hats misaligned?

 

Custom springs (based off of Progressive's springs) my shop made. 1.9" in front, 1.6 in rear. Tranny inserts only. Top hats on the front are algined (although I don't think this would cause the rear end vibration if they weren't) -- the rear I didn't believe had any? The rears seemed pretty simple....take them out and put them in. He has another set that I may swap the rears out with and see if it helps. It only happens when the rear springs are under load (acceleration).

Would the drop and higher spring rate cause an issue with the transmission bushings to fail? I do intend to upgrade to the OTTP mount after talking to Josh about them. Right now I'm just trying to setup for e85 and a test date out at Putnam Park to see if I'll like having a FWD car as a full track car or not.

 

Could be, sounds like what my car was doing before I got the wheel hub assembly replaced.

 

Was it only happening when accelerating? It's odd...but then again, I've never had rear bearings go out on me. I've had to replace the front passenger side bearing, and the car has 78k miles on it.....so it's about that time things like that start to show wear.

 

Yea and on the highway. Mine was the rear driver's side. Made the steering wheel shake pretty bad.

You could also possibly have a bent rim.

 

I don't feel it in the steering wheel too much, but I do in the seat. I ruled out tires and rims already so I'm good there. I got the car in the air and did the old tire shake test for bearing problems, but no movement. I know this doesn't mean anything though as my front one didn't move either and the bearing was still bad.

Either way, it can't hurt to replace the hub assembly(s) on the rear. I don't need anything breaking in the middle of a high speed turn. Plus it's just fun to tear **** apart.

 

have someone check if both the rear tires are balanced. then again i once saw a guy on the highway with a sedan and the driver side spring seat was bouncing for no reason on flat road. i know its hard for SS's to see that when driving but make sure both springs are seated and the wheels are balanced.

 

Wheels and tires are ok....checked those first. Checked all things rotational but the physical bearings.

I could find some muppet and talk him into being pulled behind my car on a skateboard to watch the suspension Somehow, I don't think he'd make it very far though.

I would be very interestd to see what it looks like when it's vibrating though. You may be on to something....I'm going to see if I can borrow my buddy's GOPRO cam and mount it under the car.

 

yeah the guy drove past me and the suspension was bouncing like a **** over flat ground. maybe his spring fell out and was just bouncing on the strut? idk but that **** was weird. lol

 

Video or ban, and it has to be a midget not a muppet

 

Paging s1lver --- I got $10, you want to go for a ride and help me figure out my suspension???? Bring your helmet.

 

ha. thanks.

 

Im interested as well my car is on ssc springs bmy car does the same thing