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Clunk in front end, cannot seem to find source

KT1986

Member
Joined
Apr 28, 2018
Location
Sumter, SC
A month back i replaced everything in the front suspension with new parts from kaplhenke and for the life of me i cannot seem to get rid of this clunk in the front end. I replaced all bushings, new koni racing struts and all mounting hardware. Rechecked torque three times on all these parts, borrowed the koni gland nut tool from a friend and cranked those down tight.

I replaced the tie rods as well, along with ball joints with lemforder and meyle parts respectively. Also did the rear as well with new parts all round but no issues there. Also noticed that when backing out at times it makes a clunk noise and the vibration can be felt and when taking off from a light it feels like something heavy is sliding backwards (i suspect motor and/or transmission mounts).

The only parts i didnt change were the sway bar mounts to the body but i poked, prodded and re-torqued those and they dont move a millimeter. Im at a loss as to what it could be. It almost sounds like the upper strut mounts are knocking around in the towers but i dont see any evidence of that. Any ideas guys?
 
Is this a 240? Do you have adjustable upper strut mounts? If you have adjustable camber and still have stock diameter springs. You can adjust the upper mounts to far in and the top part of the spring and perch hit the body on the inside where it is hard to see.
 
Those strut top nuts will "torque" up to spec sometimes and be nowhere near actually tight. How much strut bolt is showing through the strut top nuts?
 
Is this a 240? Do you have adjustable upper strut mounts? If you have adjustable camber and still have stock diameter springs. You can adjust the upper mounts to far in and the top part of the spring and perch hit the body on the inside where it is hard to see.

No its a 740T and it has a full coilover kit from Kaplhenke with 2.5 in ID springs from eibach. Only thing stock about it now is the sway bar end links, sway bar mounts to the chassis and stock hubs and spindles

Those strut top nuts will "torque" up to spec sometimes and be nowhere near actually tight. How much strut bolt is showing through the strut top nuts?

Id have to measure, I dont know right off hand but when I assembled them before stuffing them into the car i made sure the threaded end of the strut was shoved all the way up into the mount. There was a little sleeve that went over the threads to make it fit the larger hole in the strut mounts and I made sure that was all the way on.

These are the mounts I have: https://www.bneshop.com/collections...cts/700-900-spherical-adjustable-strut-mounts
 
Blast... that would seem (at least) to indicate they're snugged up pretty good. Might be worth checking for any odd play there though...?
 
Sway bar bushings new? Old? They can go clunk.

The end links are brand new, the mounts on the chassis are stock but have no movement in any direction. When that was suggested to me by Ben, i got out the pry bar and tried to move them but they didnt budge. I also checked the tightness of the bolts as well
 
Does a 740 have the same style 4 bolt attachment of the subframe to the frame? If so, you might check those.

Yes it has the 4 bolts for the subframe and unfortunately its gonna require me pulling things apart in there to tighten those up. Its the only thing I have left to try. If that doesnt do it, im thinking the strut inserts might be no good.

I noticed that when i was assembling the coil overs, the weight of the mounts alone would cause the sliding part of the strut insert (the silver part) to be pushed down into the strut body and made assembly a little awkward.

In other words the new strut inserts kinda behaved like the old, blown out inserts where you can grab both ends of the thing and pull it in and out very easily.
 
In other words the new strut inserts kinda behaved like the old, blown out inserts where you can grab both ends of the thing and pull it in and out very easily.
You mean instead of like a new gas-charged strut insert or shock absorber that always wants to extend to full extension?

Are your new inserts gas-charged?
 
You mean instead of like a new gas-charged strut insert or shock absorber that always wants to extend to full extension?

Are your new inserts gas-charged?

I wish i could remember what model they were, but i dont think they are gas charged, i believe they are koni 30 series single adjust strut inserts.

if they arent gas charged that would explain the ability to pull them in and out.
 
Rechecked torque three times on all these parts, borrowed the koni gland nut tool from a friend and cranked those down tight.
It almost sounds like the upper strut mounts are knocking around in the towers but i dont see any evidence of that.
I assume any spacers (if needed) were put in the struts before the inserts, and that the gland nuts don't actually bottom out on the tubes, but stop short, indicating that the inserts are being squeezed, and not just rattling around in there?
 
Had this issue with my 240 before, and it ended up being the nut on top was bottoming out on the threads before actually clamping down on the strut mount.
 
I assume any spacers (if needed) were put in the struts before the inserts, and that the gland nuts don't actually bottom out on the tubes, but stop short, indicating that the inserts are being squeezed, and not just rattling around in there?

Yes they were installed since the strut wouldnt fit properly in the hole, the only question there was on top or bottom of the mount? I put the spacer on top as the nut would be "inside" the mount and rather hard to access with anything but a socket and impact. I have a feeling that the little spacer that was given to me with the kit was supposed to go on the bottom of the mount.


Had this issue with my 240 before, and it ended up being the nut on top was bottoming out on the threads before actually clamping down on the strut mount.

In a sense I think I have the nut bottoming out before any clamping goes on and is probably moving around in there as the spacer may not be in the right position. May have to yank it apart and swap it around to see if that helps at all.

But here's a twist guys, today driving into work the car was silent (suspension wise) the entire time coming to work, and I drove over rough pavement and railroad tracks. Not a peep from the front end. I had not done anything to the car since last week and it was making noise all that time.

I also noticed this before as well where in the morning it would be quiet and then in the afternoon, the clunk would start. Its probably just coincidence but still odd nonetheless.
 
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