Installed coilovers, now I have clunks. Help!

[TMF]

I installed MCS coilovers with Raceseng top mounts, front and rear, and I am getting this clunking noise from the rear...seems to be coming from both sides:

[ame]https://www.youtube.com/watch?v=YMeI3Yj7kEc[/ame]

I thought it was the rear Raceseng top mounts, but they've already sent me replacements, and the replacements make the same noise. I've double checked all of the strut mounting bolts, top strut nuts, LCA bolts, endlinks, exhaust, etc and I can't seem to find the source of the noise.

I can replicate the noise when the car is sitting by pushing down on the rear...I've noticed that it makes the noise when the suspension hits the top of the rebound stroke. It seems like it is coming from one side, but kind of hard to tell.

I think my remaining culprits are:
-blown coilover strut (the MCS were used but the previous owner said they were fine when removed)
-possible axle issue? Each axle has a slight of amount of in/out play (only a few millimeters), but I'm not sure if this is normal. I didn't have any noises or clunks prior to installing the coilovers. I'm also not sure that it is the axles because it seems to only make the noise on bumps.

Does anyone have any other ideas or troubleshooting steps? Otherwise I think I need to set the coilovers into MCS for inspection/rebuild...which will put me behind in preparation for the first event (Midwest 86 cup at Mid-Ohio on 4/6-4/7), so I'm trying to exhaust all possibilities before sending them off.

Thanks in advance!

[StraightOuttaCanadaEh]

Did you do an alignment following the install?

My fronts made a ticking sound for a couple of weeks until they broke in.

[TMF]

Originally Posted by StraightOuttaCanadaEh

Did you do an alignment following the install?

My fronts made a ticking sound for a couple of weeks until they broke in.

Not yet...I'm waiting to do the alignment and corner balance until this gets resolved. I've already had the rear end apart about 3 times lol. I'm pretty sure that this is beyond some sort of break-in noise.

[StraightOuttaCanadaEh]

Originally Posted by TMF

Not yet...I'm waiting to do the alignment and corner balance until this gets resolved. I've already had the rear end apart about 3 times lol. I'm pretty sure that this is beyond some sort of break-in noise.

Based on a few of these threads that I've seen before, one of the solutions that's suggested to get rid of the clunks is to get an alignment.

[Tristor]

I haven't installed my top plates yet, but in doing some research it seems like anything less than perfectly torquing the top nut will cause clunking, and it may not be visible. You should ensure you torqued your top nuts correctly and that you have had an alignment performed after install.

[FastWhite]

I feel your pain. I had pretty bad front clunking/banging in the front. That was the sway bar hitting the frame due end link adjustment. Needed to lengthen the end links.
The back has a clunk, but only when I hit a dip in the road that extends the damper fully then compresses it.
Still have it, so I avoid those roads. They are BAD roads but are “ the short cut”.
I’m running the 2WNR, 550 lbs square, with helper springs. My helper springs in front are pretty much compressed at full droop, so end links my still be too short.
Otherwise on normal roads it’s all good. Couldn’t ask for a better coilover. Barring Penskes of course.


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[Code Monkey]

Make sure to zap the top nut with an impact, a couple of quick bursts should do.

[TMF]

Originally Posted by Tristor

I haven't installed my top plates yet, but in doing some research it seems like anything less than perfectly torquing the top nut will cause clunking, and it may not be visible. You should ensure you torqued your top nuts correctly and that you have had an alignment performed after install.

Although I agree that an alignment is necessary after suspension changes, only toe is adjustable in the rear on mine...so I can't see how adjusting toe is going to get rid of the clunks.

I was careful to ensure that the shock bushing slide into the bottom of the bearing on the plate when I assembled, and also that the nut properly seated in the top of the mount bearing. I used a 19mm wrench to tighten and gave it a whack with a deadblow...and when I try to tighten the top nut with the strut installed in the car, it feels like I'm just spinning the shock shaft.

I was thinking I had the wrong shock bushing and/or top strut nut, but Raceseng says they are correct and seems to be what others are running.

Originally Posted by FastWhite

I feel your pain. I had pretty bad front clunking/banging in the front. That was the sway bar hitting the frame due end link adjustment. Needed to lengthen the end links.
The back has a clunk, but only when I hit a dip in the road that extends the damper fully then compresses it.
Still have it, so I avoid those roads. They are BAD roads but are “ the short cut”.
I’m running the 2WNR, 550 lbs square, with helper springs. My helper springs in front are pretty much compressed at full droop, so end links my still be too short.
Otherwise on normal roads it’s all good. Couldn’t ask for a better coilover. Barring Penskes of course.


Sent from my iPhone using Tapatalk

Yea, it makes the noise in the rear with even small compressions. I could try removing the sway bar.

I do agree...the MCS's have a great reputation and their support has been awesome.

Originally Posted by Code Monkey

Make sure to zap the top nut with an impact, a couple of quick bursts should do.

I typically avoid using an impact on struts if at all possible. When I assembled, I did whack the wrench with a dead blow, so I'm pretty sure it's tight.

I should also note, that when I put new springs on, I swapped the left and right rear struts...it's hard to tell, but it seems like the noise is only coming from one side, and the noise followed the strut when I swapped...which kind of supports the suspicion of the strut itself.

Just to confirm, is this all the hardware the everyone else is running with the Raceseng's and MCS?

[ka-t_240]

Originally Posted by Code Monkey

Make sure to zap the top nut with an impact, a couple of quick bursts should do.

Most manufactures specifically state to NOT use an impact on the top nut and state it can damage the internals of the strut.

[strat61caster]

Which lca do you have?

[ka-t_240]

Did you double check your pre-load on springs?

How do the bushings look bottom?

Try unbolting the sway bar and see what happens to the noise.

[TMF]

Originally Posted by strat61caster

Which lca do you have?

OEM. I had the SPC previously, but went back to OEM to save on points. The car has 25k miles, so I don't think that the bushings in the LCA's are toast.

Originally Posted by ka-t_240

Did you double check your pre-load on springs?

How do the bushings look bottom?

Try unbolting the sway bar and see what happens to the noise.

Pre-load: yep, checked it when I set the right height and made sure that the collars were locked.

Sway bar...will try that later today.

Bushings...I'm guessing you mean the bottom mount bushing/bearing on the strut itself? That is actually another potential culprit. There was some play, but it did not seems too significant. I might need to double check that as well.

[ka-t_240]

The next thought i have, is do you have a way to put the car in the air, with wheels loaded? Could get under car and have someone bounce suspension unless you can find chassis ears to borrow.

I have stands I made to put my car on with loaded suspension for tightening bolts etc on suspension. Made out of 2x4. I can get the car 12 inches off the ground.

[AFRichZC6]

It sounds a lot like rear top hats not fully torqued, or your top hat bearing has play and may need replacement if they are used units (but they're not). Just a tiny bit of looseness in torque or in the bearing will cause them to clunk like that over tiny bumps in the road.

I always torque mine by giving them a couple quicks zaps of the impact gun, otherwise, it's difficult to keep the shaft from rotating in the shock body. I installed them that way on a buddy's set of MCS, my ASTs during several spring swaps, Koni yellows, etc. It's fine.

Have you tried installing the stock top hats to see if the sound is still present?