Cadillac CTS-V - Ground Control - Front lower spring mount (threaded collar) is loose and clunking

So I installed the ground control kit a couple weeks ago, and the front lower spring mounts (threaded collars) have become loose on the shocks and they have developed a significant clunk to them while driving. I tried raising the collar ring a couple threads because I thought maybe it was the spring that was loose, but that only seems to help for a day until they loosened up again.

This stuff all came to me assembled (the full front setup with FG2s, ground control and upper control arms) so I don't know what is supposed to attach the lower collar to the shock. They were definitely very tight when they were first installed, but over a couple weeks they loosened up to the point where I can spin and lift them slightly with ease when the suspension is not compressed. This is obviously what is causing a loose metal on metal clunking sound while driving, every time the suspension moves up.

Any tips for how I can tighten that up again?

I know other have had problems with the upper spring mounts and bump stops squeaking/clunking, but that is not my issue.

Are you saying that you've already tried tightening the fastening bolt (hex) on the gold rings and they're still loosening up?

I don't have GC these but found this statement and the whole link useful when I installed KW's

http://www.cadillacfaq.com/faq/answers/gcinstall/index.html

11. Install the GC front lower mount making sure the snap ring is captured inside the bottom of the threaded sleeve. Note, the setting you see in the picture is about where I have the collar set for my car.

Are you saying that you've already tried tightening the fastening bolt (hex) on the gold rings and they're still loosening up?

It's not the ring coming loose, it's the whole threaded collar that goes over the shock. That ring bolt is very tight and the ring doesn't move at all. Tightening that doesn't secure the threaded collar to the shock.

I don't have GC these but found this statement and the whole link useful when I installed KW's

http://www.cadillacfaq.com/faq/answers/gcinstall/index.html

11. Install the GC front lower mount making sure the snap ring is captured inside the bottom of the threaded sleeve. Note, the setting you see in the picture is about where I have the collar set for my car.

I looked at that, but I don't know what it means exactly. I bought this already assembled and it was all tight when I installed it. Maybe I need to hammer the sleeve back down again or something, but I don't want it to keep coming loose.

http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-performance/244944-ground-control-how-do-you-get.html

Sounds like it just presses on and stays by the weight of the car. Do you have the perch real low perhaps too low for the spring to stay compressed when the shock is at full travel.

Thanks, I had just found that thread and was just reading it. Sounds like I need to pound the collar back down and then maybe throw some tape or something around the top to prevent it from moving back up.

This is a strange situation. I wish I could take a peek at the shocks, towers, and listen to the sound. The threaded collar can move--I can rotate mine with the ring lowered and no spring tension applied, but it's not easy. I sprayed lithium grease between the shock and the collar beforehand, which may have helped.

I suspect that something else is wrong, like you're using short springs (less than 10") and not lowering the car enough to ensure that tension is always on the ring and threaded collar. When you jack up the car, you should have to really work to break the ring free (e.g. you should almost need spring compressors to take the load off before the ring will rotate).

Shorter springs would do it but I would think lowering the car too much could do it as well as the car could be sitting on the fully compressed shocks instead of the spring if you lowered the spring perch to far or lost spring tension during shock travel. I assume you could feel this driving if it was the case. I would try raising the spring perch so its higher on the threads to ensure it's riding on the springs and keeping compression even if just for testing. The kw set is similar except the shock has as threaded body and there is a helper spring under the main spring but I could see it easily lose tension if it was lowered past specs and weight was taken off the front end.

This is a strange situation. I wish I could take a peek at the shocks, towers, and listen to the sound. The threaded collar can move--I can rotate mine with the ring lowered and no spring tension applied, but it's not easy. I sprayed lithium grease between the shock and the collar beforehand, which may have helped.

I suspect that something else is wrong, like you're using short springs (less than 10") and not lowering the car enough to ensure that tension is always on the ring and threaded collar. When you jack up the car, you should have to really work to break the ring free (e.g. you should almost need spring compressors to take the load off before the ring will rotate).

I know, it was not easy to move before when I first installed everything. It was actually difficult to raise the rings a couple threads when I wanted to because the tires were tucked too much for my taste, I had the rings down to 14 threads from the bottom. When I tried to raise them it was so hard that I could only go up 1 1/2 threads.

When I went to check everything out last saturday and went to raise the rings again, it was so easy. I took them up to 18 threads from the bottom and could have gone further without issue. I'm anxious to get home and pull the wheels off again now.

Shorter springs would do it but I would think lowering the car too much could do it as well as the car could be sitting on the fully compressed shocks instead of the spring if you lowered the spring perch to far or loosing spring tension during shock travel. I assume you could feel this driving if it was the case. I would try raising the spring perch so its higher on the threads to ensure it's riding on the springs and keeping compression even if just for testing. The kw set is similar except the shock has as threaded body and there is a helper spring under the main spring but I could see it easily lose tension if it was lowered past specs and weight was taken of the front end.

I'm pretty sure the springs are correct. I don't think I need to raise the ring and tighten the spring, I would be going back to stock height to do that and plenty of people run ground control pretty low with no issues. Raising that ring is what I tried last weekend and it didn't solve the problem.

Something is definitely fishy though...

see if you can get some pictures. I'm trying to picture my GC kit in my head, but it's not working. And my car isnt here

see if you can get some pictures. I'm trying to picture my GC kit in my head, but it's not working. And my car isnt here

I will take pictures today when I get home and pull it apart. The part that is loose is the lower threaded red part of the lower spring mount. I don't remember exactly where mine are sitting at the moment but we'll see later on.

This is a pic from the FAQ, NOT from my car:

http://cadillacfaq.com/faq/answers/gcinstall/32.jpg

I doubt that the threaded collar is the cause of the clunking.

Please check the tightness of the upper shock towers--you may want to take the tower brace off before you tighten it down again to make sure that the upper shock nut (see FAQ picture 8) is on solid. Another possibility is that your control arm knuckle bolt isn't on tight enough (picture 14), allowing the vertical arm to pull out and bang around (although I can't imagine how you wouldn't have noticed that).

I'm pretty sure it's the collar, I checked everything else for tightness on Saturday. I'll report back in a few hours.

Well I pulled the wheels off and took a close look and though the collars are loose with the suspension down, I don't see how they could be moving with the wheels on and the car driving. I put everything back together without changing anything, went for a quick drive and it doesn't seem to be clunking.

Now I'm wondering if the (new) lug nuts are to blame since when I took the wheels off they seemed a little less than the 100 ft lbs I always torque them to. They weren't loose but they didn't take much to break them loose. I had drilled out the torx head screws on the front rotors when I changed them last year because they stripped, so only the wheel and the caliper hold the rotors on. It seems possible that the lug nuts coming just slightly loose could cause the rotors to be moving and making this noise. If this is the cause then I don't know what to say....kinda scary. If the noise comes back I will check the lug nuts first and see if they're still torqued and that will either rule them out or solve the mystery. I checked the rears and they are still torqued to 100.

Well its definitely not the lugs...still clunking. Must be something else..

I am kinda of surprised the collar would be loose with just weight off the spring with upper/lower control arms still connected. I wonder if that was designed that way or if the perch is lower than it was originally designed for even though the threads exist. The original post stated 0 -1.2" drop.

There shouldn't be any movement at all on the collars. It should be snug. Strange

Here is a picture of mine:

http://i305.photobucket.com/albums/nn240/ctsv510/IMG_20120510_182723.jpg.

and a video. The more I lower the suspension, the more movement I can get out of the collars

http://i305.photobucket.com/albums/nn240/ctsv510/th_VID_20120510_182753.jpg (http://s305.photobucket.com/albums/nn240/ctsv510/?action=view&current=VID_20120510_182753.mp4)

I think that most of that sound is coming from the top of the spring hitting the upper retaining ring. Again, there's nothing there to stop the collar from sliding up and down--only the force exerted by gravity (i.e. the weight of the car) prevents the springs from floating and slapping the upper and lower retainers.

As before, I suspect that these springs are 8" (normal is 10"), and you don't have adjustable or shortened end links (e.g. C5/C6 Corvette end links) that would prevent slack from opening up and causing that sound. Normally Eibach springs have white printing on the coil jackets that identify length, diameter, and spring rate. It almost looks like the guy you bought these from polished the lettering off.

Again, I would also check your upper shock retaining bolt, which will require removing the shock tower brace. Spraying some lithium grease between the shock and the collar might also prevent a good chunk of that float by adding a touch of friction.

Just to clarify: this "clunk" is happening on both sides, right?

I think that most of that sound is coming from the top of the spring hitting the upper retaining ring. Again, there's nothing there to stop the collar from sliding up and down--only the force exerted by gravity (i.e. the weight of the car) prevents the springs from floating and slapping the upper and lower retainers.

As before, I suspect that these springs are 8" (normal is 10"), and you don't have adjustable or shortened end links that would prevent slack from opening up and causing that sound. Again, I would also check your upper shock retaining bolt, which will require removing the shock tower brace. Spraying some lithium grease between the shock and the collar might also prevent a ood chunk of that float.

Just to clarify: this "clunk" is happening on both sides, right?

I didn't measure the length of the springs, but they are the ones that come with the ground control kit. I do have the shorter z06 endlinks installed.

I do believe it is happening on both sides, but I am going to have someone else drive the car around the bumpy parking lot here at my office while I can listen from outside the car and on each side.

Crank it up a few rings so it's slightly tight when it's unloaded.

Is it just me or shouldn't there be "cups" at the top of the shocks/spring? Like a rubber thing to keep the spring from moving around and making noise? Even my QA1's that I recall had them.
Throw a piece of garden hose on the top coil and see if the sound at least goes away

Crank it up a few rings so it's slightly tight when it's unloaded.

I may try that next, though it will put me back to stock ride height which I shouldn't have to do. If the clunking stops then it would however tell me something.

Is it just me or shouldn't there be "cups" at the top of the shocks/spring? Like a rubber thing to keep the spring from moving around and making noise? Even my QA1's that I recall had them.
Throw a piece of garden hose on the top coil and see if the sound at least goes away

The kit doesn't have any pieces like that but I have heard of the garden hose trick. Something else to try when I have time. You can see from this picture from the FAW install instructions that the top and bottom spring mount is spring on metal:

http://cadillacfaq.com/faq/answers/gcinstall/31.jpg

I did a quick search and found this guys album
http://www.submariner.org/thepno95/Pictures/CTS-V%20pics/Suspension%20and%20Chassis/KW%20coilovers/
His upper mount is more substantial than what yours appears to be. It's almost like you are missing a piece

http://www.submariner.org/thepno95/Pictures/CTS-V%20pics/Suspension%20and%20Chassis/KW%20coilovers/KW%20-%20front%20-%20labelled.jpg

That's because that KW kit is over $2000. It has more pieces.

Here is a picture of mine:

http://i305.photobucket.com/albums/nn240/ctsv510/IMG_20120510_182723.jpg.

and a video. The more I lower the suspension, the more movement I can get out of the collars

http://i305.photobucket.com/albums/nn240/ctsv510/th_VID_20120510_182753.jpg (http://s305.photobucket.com/albums/nn240/ctsv510/?action=view&current=VID_20120510_182753.mp4)

I flip open Grassroots Motorsports and page 151 ground control ad shows some coil over springs with the top piece inverted position compared to yours. The small part of the cone to the nut side and the wide part to the spring side yours looks opposite of that which would raise the spring in relations to the shock and lower the car further. I flip over to the faq and ground control page and the part there doesn't really look like your part.

http://www.ground-control-store.com/products/description.php/II=715

Grassroots Motorsports did a article on buying a used V1 in this issue.

That's because that KW kit is over $2000. It has more pieces.

Its right at 2k shipped and probably similar parts as the shock has the threaded body but an extra spring also the kw kit comes with no extra bushings as it retains all stock upper shock and strut mounts unlike the gc kit. I installed it this week and the feedback and control is awesome. I have never had a good kit like this on any car prior (closest was a ford performance handling kit for 1994 mustang gt)and this kw kit has most likely ruined the idea of stock suspension on future sports car purchase.

I flip open Grassroots Motorsports and page 151 ground control ad shows some coil over springs with the top piece inverted position compared to yours. The small part of the cone to the nut side and the wide part to the spring side yours looks opposite of that which would raise the spring in relations to the shock and lower the car further. I flip over to the faq and ground control page and the part there doesn't really look like your part.

http://www.ground-control-store.com/products/description.php/II=715

Grassroots Motorsports did a article on buying a used V1 in this issue.

I think those parts are installed correctly on mine. The part on the ground control website I think only shows the top of the upper spring mount, so you can't see the bottom part, which is what you do see in my pictures.

the nut on the top needs to be tightened more if I remember correctly

Try that and see what happens

orrrrrrr, tighten up the gold bracket a little more. See if that takes the slack outta the spring.

the nut on the top needs to be tightened more if I remember correctly

Try that and see what happens

I've told him that twice already and he hasn't responded.