MI-Z/28

Installed SFC's, LCA's, PHB, and sway bars. Didn't realize they needed to be preloaded until a friend told me. Went back and preloaded them after about 1000 miles of driving. Everything seemed fine. I have since put a few thousand miles on the car and notice a clunk/rattle coming from the back of the car when going down bumpy roads. I've checked for loose bolts on the parts I've installed and they all seem fine to me. All bushings have been greased. I can't seem to isolate the problem. Any ideas as to what might be causing this? Is this a normal occurrence after switching to poly bushings?

98pontiac

I went to all poly, and the ride is harder, and little more bump noise, but I dont hear clunks or anything out of the ordinary. clunks can even occur if you have any garbage in the trunk moving around. I would double check everything for tightness. If you touched any part of the exhaust the exhaust could be banging. Otherwise check the shocks even. Try bouncing the car up and down to get it to make noise. other than that, check sway bar and links, and sway bar bushings. Get under there and basically wiggle everything around and see if there is play in anything. It has to be one of the above... panhard rod and trailing arms are the only other things back there.

jsteele90

iTrader: (13)

i would put a load on the suspension and retorque everything. more than likely its the lower control arms

jeepers_88

iTrader: (13)

anytime you remove the factory rubber for poly or solid mounts, youll pick up noise. after I did my LCA reloc brackets, eibach drop, and panhard bar, I picked up a clunk in the rear, usually when backing out of my driveway and hitting the drainage ditch (load change/reversal) I think I have it narrowed down to the one solid bushing on my panhard bar. Its just the nature of the parts. My friend put solid lower control arms on his 07 gt, the first time I took a ride in it I thought the rear end was going to fall out of the car thats how loud they were, you could litteraly hear every bump in the road. If you know everything is tight, I wouldnt worry about it.

MI-Z/28

I've checked the jack and spare tire, both are tight and not moving around. Nothing in the trunk either. Exhaust has plenty of clearance. I've tried bouncing the car and cannot get it to replicate the noise. It does it only when I'm driving and hit bumps and cracks in the road. I changed the oil the other day and while I was under the car I checked all the bushings and endlinks, double checked bolts on all the parts I installed, and made sure everything had grease. Initially I was confident that I had a loose bolt on the PHB or LCAs, but it's not the case and is why I'm more confused now.

I thought LCAs too, but I did this and still have the clunk/rattle while driving over bumps/cracks in the road.

That's what my car sounds like going over larger bumps. Sounds like I busted the rear end. I expected a little more noise from poly bushings, but this just doesn't seem normal to me. But I've never rode in another fbody with poly bushings on the LCA, PHB, etc. Maybe it is just the nature of the bushings.



Anyone have the torque specs on the LCAs, PHB, and sway bars? I misplaced the instructions UMI sent with them.

jsteele90

iTrader: (13)

i have all the same aftermarket suspension as you. sfcs,lcas,reloc brackets,panhard, and sways. and have none of this extra noise everyone is talking about. maybe check your hardware for your shocks. there has to be something loose down there. do you have access to a drive on lift? that would be one of the easiest ways to check. check all your exhaust as well for excess play or rubbing