JIC FLTA2 - who has clunking?

[ounkny]

This is an informal poll: does anyone experience clunking sounds from their JIC FLTA2 coilovers (not talking about swaybar or endlinks clunking)?

My rear coilovers clunk when hitting medium-to-large sized bumps. This persists even after we have corrected some problems with the installation (tightening nuts on the top, and adjusting the spring preload). They have clunked when set at 3F 5R, 5F 6R, and 6F 7R, so I haven't been able to make it go away by adjusting the damping.

 

[ARD MP5]

I think you might want to check that center nut I was indicating. I've tightened this often on vehicles that exhibit a pillowball "clunk" sound from the uppermount. I know you mentioned he must have checked it but double check it with a ratchet. You can do it yourself. Don't worry about how hard you try to tighten it. Do it with the wheels on the ground.

Rishie

 

[2K3 MSP]

Rishie, is it possible to pick up just a rear set of the full coilovers?? JIC, Tein, or anyone else that makes them for the MSP?? I'm tired of my rear being so much higher than the front(Spool springs), and I'm afraid there's no other way around it...Any ideas?? I was curious about the 5 way adjustables you have, but I'm not sure if that would solve the problem...

 

[soundbombing]

i have b&g's coilovers. i have the same clunking in the rear when going over bumps swiftly. it sucks. i also have a pop sometimes on the front when turning. that is usually after not driving for a little and only when taking off, not on the street. on uneven pavement and driveways i get noises but i don't hear them anymore b/c i'm use to it.

i know someone with jic on their 350z and they get "noises" also.

 

[BlueMP5Dave]

I know this may sound unusual but when I had my sedan I just put some 3 in 1 oil in my two front pillowball mounts and it took care of the clunking and poping. I live in sand hell here in Vegas and quite often road trash would get all over the dampner cyclinders and I had to wash those down also. Washing them down and keeping the pillow balls lubed keep my care pretty noise free. You have to remember also that this suspension is full on race gear and is not going to be quite as quiet as stock suspension. To add to what Rishie indicated also make sure you don't have them set to low. Three inches of travel is probally the minimum travel you will want to set these at and I recommend you give them more than that. Hope that helps

 

[ARD MP5]

I don't belive you can buy just a rear set and I wouldn't recommend it. I would buy different springs like Eibachs an sell the Spools.

Otherwise get a set of Ground Controls for the stock dampers. You can also get the illuminas from us and the Springs from Dave above. He's got a banging deal.

Rishie

 

[ounkny]

I tried to tighten the center nuts on both the LR and RR coilovers. Although I did feel that they were tightening, eventually the nuts kept turning, so either there was no more thread or not enough friction somewhere to get the nut any tighter.

I also reset my spring preload, and adjusted my damper settings to 7F 5R as suggested by a rep. from JIC.

The clunk is still there when going over bumps, from the rear, both sides. Whatever wheel hits the bump is where the sound comes from.

 

[ounkny]

update

I found that lowering the rear damper settings reduces the clunk but does not completely eliminate it. It's a shame to not be able to run the damper setting I want (somewhere between 5 and 7) and having to settle for a lower setting (3). I will continue the troubleshooting.

 

[melicha8]

Also try checking the sway bar. When I had a clunk when I first put them in. My rear passenger side was clunking and I found that it wasn't the coilovers at all but the link on the sway bar wasn't tightened all the way

 

[ounkny]

That is definitely a good suggestion that has solved many people's clunks. Unfortunately, I don't think that is the case with mine. The installer used air tools to tighten my swaybar endlinks, and there's no way I can tighten it anymore by hand. I feel it is very tight and it is not making any noise. The only swaybar issue I have had is a minor squeak from the bushings but I think that is pretty normal in the winter because there is more play (since the rubber is not expanded).

 

[ounkny]

i give up

After my 5th visit to the installer, I am out of ideas for how to solve the mysterious rear suspension clunk. This last time we made sure the center nut at the top of the strut was tight, using an impact gun, as recommended by JIC. No use, because the nut was already tight. The times before that we made sure the 3 nuts holding the strut to the tower were tight, made sure the spring preload was snug enough, and replaced the stock endlinks (because they broke during the coilover install).

I definitely feel like the clunk is coming from the top of the shock tower, and not from underneath, as would happen if there was a problem with one's rear swaybar or endlinks. I also believe that my clunk is probably the same clunk that soundbombing has with his B&G coilovers, and he doesn't even have pillowball mounts!!! Therefore I'm not sure I necessarily agree with the assumption that any noise the units make are coming from the pillowballs. Should they be noisier? Yes. Should they be making this loud clunking/thumping/metal banging sound when going over bumps? No.

I have done so much web research that I should have a degree in coilovers. There are some people on the WRX and Skyline forums that have been having the same problems, and they also call it a mysterious clunk. I've even heard one person go so far as to say that with JICs you get a clunk, but ignore it, that's how you know you have a kick-ass suspension!

I think this is clearly not the right approach, especially if we are not sure what the cause of the clunk is. Why don't the fronts clunk? They use pillowballs too! What is most troublesome is that some JIC owners do not experience the clunk. I've done all I can to troubleshoot this hands-on. I hope some others will be able to provide some insights on this problem. Thanks to all those that have tried to help.

 

[thewrench]

Man, I'm at a loss as to what to tell you. I've been trying to pay attention to what sounds I hear from the rear end, and I've determined that I have no clunk. Well, that's slightly untrue, when I have a paticularly hard hit I do get one, but I'm pretty sure it's coming from my swaybar One idea would be to get a dial guage and unweight and weight the suspension to see how much slop the pillow ball has. Try this on all 4 corners to see if there's a measurable difference. There maybe problems with machining tolerences, especially if the top of the shock shaft has a shoulder. The inside of the pillowball mount may be slightly machined too large. If I think of anything else I'll post it.

James T

 

[ounkny]

What do you think about this alternate hypothesis (to the common excuse that pillowballs are noisy) concerning the rear suspension clunk?

Most people seem to be getting clunks after installing stiffer springs in the rear, but hardly anyone gets clunks in the front. While I was watching my installer try an impact gun to the top center nuts on the coilovers, I noticed that the whole rear deck vibrated as he tried to tighten them (but in fact, the nuts did not move because they were already tight).

So I think one possibility is that the clunking sound when going over bumps is similar to the kind that you hear when riding a schoolbus and it goes over bumps. You hear banging sounds all over the place, presumable because the chassis isn't stiff enough to withstand the force. The chassis therefore flexes and makes a lot of metal-to-metal noise.

If I had to speculate, I would say the front shock towers are much beefier than the rears. Maybe that's why the fronts are silent and the rears make the clunking sound, but only when going over bumps large enough to have sufficient impact on the chassis.

Also, we know that there are slight differences in the design between the Pro sedan and the P5. If I understand correctly, there is nothing that connects the tops of the shock towers in the P5, maybe that's why the P5 owners don't get a clunk, because there is no metal piece there that's flexing.

 

[melicha8]

Are your top strut mounts slotted or are you having to use crash bolts to adjust the camber? The problem you may be running into is that you're struts are sliding around. Are you hearing the clunk on turns or on straights. Mine were sliding around for a while and were making a clunk because of it.

 

[melicha8]

Oh was just thinking of another thing. The bedliner in your trunk may also be bouncing up and down. This is a clunk I also often hear because the rear springs are so stiff

 

[ounkny]

melicha8,

1. i assume you meant LOWER strut mounts (the ones that attach to the knuckle). they did not come slotted from JIC (grumble) and I didn't have camber bolts so the alignment shop had to slot them. However, this should not be the primary cause because they were clunking even before i got the alignment (when the lower strut holes were NOT slotted).

2. i tried playing around with my bedliner and spare tire yesterday. I think the only way to know for sure is to remove both from the car and test drive it. i will try that this week.

 

[thewrench]

No, he's talking abou upper bolts. some people slot them to adjust camber for autox, or if the car was wrecked and is way out of alignment.


JT

 

[ounkny]

I see. The only bolts I had slotted were the lower bolt holes on the rears. However, I still think this is irrelevant to my particular problem because I had the clunk before anything was ever slotted.

Has anyone else had problems after slotting?

 

[ounkny]

I just tried 2/2 damper settings (i usually use 5/5). I think the ride is absolutely horrible when going over bumps (and it still clunks). This is probably what people mean when underdamped springs feel "bouncy." I think what's happening is when I hit a bump, the vertical acceleration caused by the spring is too fast (since the shock valving is low), and the car ends up feeling like a rollercoaster. I think I will go back to the 5/5 setting that has given me the best ride quality so far.

5/7 handles better than 5/6 or 5/5 but I found 5/5 to have the best ride.

melicha8: to answer one of your questions, turning has nothing to do with my clunk. The only thing that matters is that I hit a decent-sized bump. Over very small bumps (for example, potholes that have been filled in, but aren't quite even) the suspension is completely silent, so it is not a rattling sound or anything like that.

 

[duMb KeoLa]

clunk...could be your rims hitting the top of the wheel well??? i dont know if you covered this already but im just trying to think of something...i too just got my set of jic coilovers and LOVE IT!!! the only thing that i have wrong with mine are that the rear ones tow in A LOT, and the passenger front tire seems to hit the wheel well and shave some rim and tire off....OUCH!!! im gonna get it aligned hopefully this week..any one else had had the rear tow and passenger front problems???

thanks in advanced