Warning!!! contact between front springs and strut tower is possible

[grey fist]

Didn't see another post on this so thought I would give a heads up.

My setup is B8s and Swift springs but don't think this is necessarily unique to this combo.

When I did the install pushed top hats as far inboard as they would go before tightening the nuts to maximize static negative camber, no modifications, just used up all the tolerance in the factory holes.

Over time noticed a resonance or vibration at suspension frequency on certain road surfaces. Put a wrench on everything suspension related and didn't find any thing loose. Chalked it up to the fact that I had deleted the factory damper weights.

Drove it like this 2 years until one day it started making a groaning noise at full steering lock. Back under the car to investigate. Turned out it was the spring making contact with the strut tower. Fix was loosening nuts and allowing top hat to center before tightening. Groan gone, vibration gone.

Verdict: there is minimal clearance between spring and strut tower, a couple mm at best, and it is possible within factory tolerance for there to be contact. Add this to items to check if any suspension noises.

 

[DaleFredriks]

So as one not super mechanically knowledgeable on suspension, how likely is this to happen to me on Mountune springs and stock shocks, if at all? Or if I went with Mountune and B8, how does that work?

Sent from my IN2025 using Tapatalk

 

[grey fist]

...how likely is this to happen to me on Mountune springs and stock shocks, if at all? Or if I went with Mountune and B8, how does that work?

Probably OK if you don't push the top hat all the way inboard like I did. Easy to check by pulling a wheel.

 

[kevinatfms]

Tolerances.

I pushed mine all the way in and have the same B8/Swift combo without a single issue.

 

[grey fist]

I pushed mine all the way in and have the same B8/Swift combo without a single issue.

Yeah, contact only happened on one side on mine. I can guarantee you're close though.

I'm pissed that I probably have bare metal because it took so long to figure out. Never occurred to me that it would be this close to check.

 

[mosephuss]

Resurrecting this thread, by the top nuts, are you speaking of the three that mount the strut to the chassis on top? Your issues sound a bit like what I've been dealing with.

Been having issues since the day I installed my struts and before then, I've replaced a ton of parts and would hate for that to be it. I kinda doubt it and just think there's something loose somewhere, but I'm beginning to wonder if something suspension or steering related has come loose or isn't installed properly.

 

[grey fist]

...by the top nuts, are you speaking of the three that mount the strut to the chassis on top? Your issues sound a bit like what I've been dealing with.

Yeah, simple to troubleshoot by loosening the nuts and pulling strut top outboard, if noise goes goes away you found the problem.

 

[mosephuss]

Yeah, simple to troubleshoot by loosening the nuts and pulling strut top outboard, if noise goes goes away you found the problem.

Welp I'll have to give this a go. I don't have any noise but at this point am gonna have to try everything. I'm guessing you have to do this with the car jacked up?

 

[MauiRoads]

I installed Swift springs and had no clearance problems. Looking for more camber, I installed CompBrake adjustable top hats and got about 2 degrees negative camber. I have some rattling or knocking noises over small bumps. I raised the front end, and turned the wheels lock-to-lock. Turning to the right, I heard binding. I pulled the right wheel and saw that at least two of the coils were contacting the inner side of the strut tower, and the undercoat was worn off the tower at the points of contact. No similar problem on the left side. I used a hard dowel and deadblow hammer and pushed the sheet metal slightly away and the binding is gone. A slight reduction in camber (moving the three top studs outward) would likely have the same effect. Unfortunately, the knocking sound continues and I'm looking into that.

 

[M-Sport fan]

^^^Are you still on factory style dampers with rubber bushings on the actual mounting points?

Or did you install something with spherical bearings/bushings on those mounting points??

(I know about that CompBrake top mount's bushing setup, but the same on the bolt through actual damper mounting points will cause even more knocking, even on relatively smooth roads. )

 

[MauiRoads]

^^^Are you still on factory style dampers with rubber bushings on the actual mounting points?

Or did you install something with spherical bearings/bushings on those mounting points??

(I know about that CompBrake top mount's bushing setup, but the same on the bolt through actual damper mounting points will cause even more knocking, even on relatively smooth roads. )

On the stock struts, I replaced the stock springs with Swift springs and the stock top hat (dished triangular plate with rubber center mount and three studs) with the CompBrake top hat with and adjustable/sliding spherical bushing, mounted to the chassis strut tower with three bolts from above, through the tower holes into the CompBrake top hat.

I've adjusted the negative camber from 2.25 degrees down to 1 degree, but the knocking over speed bumps and some smaller bumps continues. I've detached both sway bar end links, but those were not the problem.

I've noticed that the stock top hat, with its dished shape puts the large rod nut lower than the CompBrake nut/bushing. That might add more preload to the spring, but I don't know if that could cause the knocking.

 

[M-Sport fan]

^^^OK, yes, I was speaking to the lower damper mounting points, front and rear, which are (higher durometer on the aftermarket ones) rubber on all of the factory style struts/damper setups.

I had a set of LG Motorsports Bilstein fully threaded, alloy body coil overs with Hyperco springs over them, on my 2000 Z28, which had spherical through bolt mounts at all four corners, top and bottom.

They knocked sooooo horribly even over decent roads that they set off that LS1's under the intake manifold mounted knock sensors!!

 

[MauiRoads]

^^^OK, yes, I was speaking to the lower damper mounting points, front and rear, which are (higher durometer on the aftermarket ones) rubber on all of the factory style struts/damper setups.

I had a set of LG Motorsports Bilstein fully threaded, alloy body coil overs with Hyperco springs over them, on my 2000 Z28, which had spherical through bolt mounts at all four corners, top and bottom.

They knocked sooooo horribly even over decent roads that they set off that LS1's under the intake manifold mounted knock sensors!!

Sorry...wasn't following your question, but it makes sense now. I have factory lower strut mounting: just the two lower bolts per strut.
As a last resort, I'm going to adjust to 0 camber. If the knocking is still there, I'll be 100% sure it's not a clearance problem. Unfortunately, since I'm just working on jack stands, I may have to pay a shop to get it on a lift and really pry and wiggle things around.

I had no noises before installing the adjustable top hats; the sliding part of the top hat is locked tight to the hat, and the hat is bolted solidly to the strut shaft below and the strut tower above. I'm baffled.

 

[MauiRoads]

Given how close the stock springs are to the inward part of the strut tower, it seems to make more sense to get negative camber by moving the lower control arm's ball joint outward, rather than moving the upper strut mount inward. I'll be looking into adjustable-length control arms, or eccentric control arm bushings.

 

[M-Sport fan]

It is hard to tell from that pic, but are those CompBrake top mount's spherical bearings lined (between the damper shaft contact part and the outer mounting casing) in any type of Delrin, or other hard plastic liner material??

If not, and purely ALL metal, I would expect them to make a bit of noise over any (even tiny) bumps in the road.

 

[MauiRoads]

It is hard to tell from that pic, but are those CompBrake top mount's spherical bearings lined (between the damper shaft contact part and the outer mounting casing) in any type of Delrin, or other hard plastic liner material??

If not, and purely ALL metal, I would expect them to make a bit of noise over any (even tiny) bumps in the road.

Thanks M-Sport Fan. Yes, the bearing is all metal. I understand in general why an all-metal bearing would transmit more road noise (NVH), and I understand that as bearings wear, tolerances will increase and the bearing will make noise as the center closes a gap and contacts the shell. But I don't understand why a brand-new bearing that has no free-play and is difficult to rotate in its shell, could move enough to make a metal-on-metal clacking or banging sound.

Today, I adjusted the top hats to have zero camber, just to eliminate possible spring/tower or other clearance issues. This is less camber than before I installed the solid top hats. I previously had about 1 degree negative, with the stock struts, Swift springs and camber bolts. From below, now I can see the clearance between the springs and towers, but the noise continues. Of course, that is with the suspension in "full droop" on jackstands. I can't see into the tower with the car on the ground and the suspension partially compressed. I've tried a jack under a control arm, but I can only compress the suspension so far before that corner starts to lift, instead of compressing the spring more.

 

[Dialcaliper]

Thanks M-Sport Fan. Yes, the bearing is all metal. I understand in general why an all-metal bearing would transmit more road noise (NVH), and I understand that as bearings wear, tolerances will increase and the bearing will make noise as the center closes a gap and contacts the shell. But I don't understand why a brand-new bearing that has no free-play and is difficult to rotate in its shell, could move enough to make a metal-on-metal clacking or banging sound.

Today, I adjusted the top hats to have zero camber, just to eliminate possible spring/tower or other clearance issues. This is less camber than before I installed the solid top hats. I previously had about 1 degree negative, with the stock struts, Swift springs and camber bolts. From below, now I can see the clearance between the springs and towers, but the noise continues. Of course, that is with the suspension in "full droop" on jackstands. I can't see into the tower with the car on the ground and the suspension partially compressed. I've tried a jack under a control arm, but I can only compress the suspension so far before that corner starts to lift, instead of compressing the spring more.

As you’ve picked up, it’s probably not the bearing making noise, but it is transmitting more shock through the interface. A lot of the NVH it comes from road contact, but also stuff like the sway bar/end links and control arm vibrating.

However, what you’re hearing or feeling could just as easily be something on the car body side between driver and the shock hat that is now rattling because of the increased vibration transmitted into the engine bay. So if nothing on the suspension assembly seems to be the direct cause, start looking around

 

[MauiRoads]

Thanks so much, Dialcaliper. That makes much more sense to me. Given the checks and re-checks I've done, it seems very unlikely at this point that it is the strut unit (including solid top hat) that's making the noise. I've spent some time tightening engine mounts, subframes, cross-braces, sway bar mounts, etc., and will focus more on the rest of the front chassis. I'll check the control arm ball joint and inner-end bushing; inner and outer tie rod ends; rack mount bolts; and remove both sway bar end links completely, rather than just disconnecting one end and zip-tying it in place.

 

[TyphoonFiST]

Thanks so much, Dialcaliper. That makes much more sense to me. Given the checks and re-checks I've done, it seems very unlikely at this point that it is the strut unit (including solid top hat) that's making the noise. I've spent some time tightening engine mounts, subframes, cross-braces, sway bar mounts, etc., and will focus more on the rest of the front chassis. I'll check the control arm ball joint and inner-end bushing; inner and outer tie rod ends; rack mount bolts; and remove both sway bar end links completely, rather than just disconnecting one end and zip-tying it in place.

I am now dealing with clunking. NOS OEM with Swifts. New end links and Sway bar bushings. Still clunking. Re-torqued Swave 4 point brace also. Still Clunks. Was fine for like a year after install. Now I get this filth.FML. i think it might be Strut mounts. Any Ideas?

 

[MauiRoads]

The sound I was hearing was more of a clack or tap than a clunk, and it went away when I reverted to stock top hats. I'm convinced that the adjustable, spherical top hats themselves were fine, its just that they increased NVH enough to amplify regular chassis sounds, or maybe introduce a new one that was laready on the threshold.

However, when I first installed the Swift springs with my oem struts and top hats, the springs were contacting the inside of the strut towers. That was a different sound, more like a bang, on compression. As mentioned above, I massaged the inside of the strut towers and took care of it. There's plenty of room for that mod.