pHEnomIC

iTrader: (14)

My car is clunking like crazy when going over bumps. I havent had a chance to get underneath and check but it sounds as though my sfc is banging against the body. It doesnt sound like exhaust or anything like that.

I got bolt on sfcs so it is possible they came loose. Is there anything else to check for down there that might be clunking hard on bumps?

Is it common for these things to come loose?

02TransAm/Batmobile

iTrader: (32)

I'm having the same problem on the left side rear tire area. I've noticed the clunking after I put on the Subframe Connectors. Bump for an answer.

ls1adamls1

iTrader: (9)

weld the subfrme connectors......its way stronger and your frame will stay where it needs to be.....u dont want those things loosening up

02Z28LS1

iTrader: (2)

well, first tighten up the bolts holding them on to see if that is the cause.....if so, use some threadlocker on the bolts to keep them from backing out again.

then when you get a chance (unless you don't want to permanently modify the car), get those puppies welded in, and you should never have that problem again.

if it's not those bolts that are causing the problem, start tightening other stuff a thing or two at a time until the clunking stops....when it stops, you know the last thing you did was the cause, so take steps to keep it from happening again, if possible.

chupr0kabra

iTrader: (10)

I'm betting your lower control arm bolts just need to be torqued (80 ft-lbs).


-Mike

DrkPhynx

Sounds like the noise I have. It's coming from the rear, not under my seat, so I don't think it's the SFCs themselves (especially since they are SLPs and were welded in by a chassis shop). It really only started (that I can recall), after I swapped the shocks to Konis and replaced the PHB and did the heater hose mod.

When I pop the hatch and push down on the car, it moves nice and smoothly, no clunking at all. When I go over shallow rises, or into slight dips, again, smooth as glass and no clunking. It's when I hit a seam in the pavement, or a recessed manhole cover (which are all over the place around here), or any other similar sort of bump that sends a shock through the chassis - even one barely large enough to feel in the seat.

It's driving me nuts. I have had the back of the car up a few times, re-checked the torque on the PHB, and banged and pushed on everything and I just can't find the noise.

The Jack and Spare are removed. That didn't make any difference at all.

pHEnomIC

iTrader: (14)

Well I took a peak underneath and OMG!!!!

Missing my lca nut. The bolt was still through the hole surprisingly. Im surprised it still was in there. I double checked torque on my suspension twice so i am really surprised. In fact, ive been driving like this for a week. I happened to have a nut that was non-metric but close so i have that on there temporarily.

Whats a good place to get a new bolt and nut for this the same size as stock?

Roadhouse

iTrader: (8)

Hardware store Bro. Bump up about the mystery clunk. I've been chasin' this for a while now and coming up with nothing.

99'CajunFirehawk157

iTrader: (57)

Sounds like you'll need a bolt too then if you forced it....?

pHEnomIC

iTrader: (14)

The hardware store never has the right bolt i need. I am very unsuccessful in finding hardware i need.

Ericbigmac83

iTrader: (19)

Mine clunks, cant figure it out for the life of me

DrkPhynx

Everyone who has the clunking noises, what parts do you have on the car?

I have :
- a UMI double adjustable (rod ended) PHB
- 4/3 Koni's with the front lower perch and rear heater hose mod
- welded SLP SFCs (and an SLP STB).

The jack and spare are out of the car (and pulling them out made no difference).

The car is stock, and empty otherwise.


I'm curious if there's a pattern to who has the clunk and what parts they have.

koolaid_kid

iTrader: (21)

Try Ace Hardware. You would be surprised at their collection of both American and Metric bolts and nuts. Much better than Lowes, much to my surprise.

nicks2ndz

iTrader: (13)

when i had my clunk it was the clamshell was loose on the torque arm

Ericbigmac83

iTrader: (19)

I had thought it might have been that, but mine seems to be tight.

When i welded up mine i used a jack to hold up the sfc flush to the car so i could weld it. What if i accidentally supported the car some and thats what is causing my clunking

02TransAm/Batmobile

iTrader: (32)

I noticed the clunking after installing my bolt-on subframe connectors and adjustable panhard bar both by UMI. Don't know which one it is since I put them both on at the same time.

DrkPhynx

If you don't mind me asking, how did you track it down to that and determine that was the cause?

DrkPhynx

My SFCs are SLP. I had a chassis shop (that built race cars as their primary bread and butter) install mine. I asked that they first bolt the SFCs in to spec, then weld them. (I stressed repeatedly that they load the suspension during the installation. I have confidence in their work, I've seen no gap or door fittment issues after the install, and I saw the other work they do there)

So, I have a different brand, design, and installation type than you, but we share the PHB. That makes me think that might be the culprit.

Do you still have your factory PHB? If so, try re-installing it and see if the noise goes away. I keep meaning to do that but just don't have the time right now (unfortunately).

pHEnomIC

iTrader: (14)

Alright well my clunking was solved by the lca bolt, i am amazed the screw stayed in there for a week without a bolt on the end, wouldve been bad news if it made it's way out.

Btw, i stopped at a new ace's today, wow! They do have a good selection there. Im gonna be going there more often. Lowes and home depot suck, they never ever have the stuff i need. I assumed that ace was the same as aco hardware so i didnt think about going in there (aco is decent but they still don't have the selection ace has)

02TransAm/Batmobile

iTrader: (32)

Yea, I still have the stock Panhard Bar somewhere. Don't think I'd actually reinstall it though.