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I'm trying to track down and eliminate suspension noises that have grown more annoying over this last year. The car has 140k miles on it, all my doing, and the only suspension related thing I've ever done to it was change the shocks to DRM Bilsteins w/ poly bushings around the 75k mile mark. Additionally, one of the rear wheel bearing assemblies was replaced when it starting singing. Everything else is 100% original. Just to be clear, I'm not noticing any adverse issues with the handling of the car, just general creaks and groins.
I was able to get under the car yesterday and take a look around. Overall, the control arm bushings and ball joints visually look ok. The sway bar end links also look ok but I know those tend to make noises and I may not be able to see the problem with them. There is an obvious issue on one of rod ends where the boot is nearly gone. I also saw that the bushings on the rear leaf spring seemed to be very dry and cracked. Not sure how much of an issue that is.
Is there anything else I should be checking?
On an unrelated topic, I see some heat shielding between the torque tube and the body. Does anyone know if that is only towards the front or if it runs the full length? I'm the original owner so I know no one else added it.
Mine has groans and creaking also mostly when you back out of the drive and the first few blocks with 65k, I'm always surprised, I've had vehicles with 4 times the mileage that were quiet, I've greased under the spring pads and also the front sway bushings with no luck. Maybe it's endlinks or shocks even though they look fine??
At that many miles I'm not too surprised. All of that rubber is starting to dry-rot and it even looks like that steering arm bushing at the knuckle is pretty jacked.
But everything from your control arm bushings, top hats, sway bar end links, sway bar bracket bushings, all that rubber is a possible suspect.
The bushings in each of your photos look significantly worn or already torn up. My suggestion would be to start at the front suspension & work your way to the back replacing all the bushings. It will be a big job but a good winter project.....just do a few at a time.
You'll be surprised just how much those sway bar end links will groan, creak, and pop. They're a very common noise source on the C6. If it's all original, my money is on the end links. Mine looked perfectly fine and I was convinced that wasn't my problem. After having no luck tracking my issue down, I decided to change them since they're cheap and easy to replace, plus I didn't know if they were old. Sure enough it fixed all of my suspension noise. All four can be changed out in ~30 minutes for ~$100. I did it on my ramps with no trouble. I have 160K on my C6. I replaced mine with OEM at ~105K, then they started making the infamous clunk after about a year and a half. So at around ~120K I bought four of the Moog K750136s when I swapped sway bars. Smooth and quiet ever since
Sway bar end links last around 30K or hard driving before they need to be replaced (will become loose/worn and click).
Shocks last around 35K before it's really time to replace them as well.
As for at 100K (on at least your second set of the above), yes on just about every pivot point part linkage in the suspension not covered above should be replaced to tighten them back up, and stop the noise. Also, not a bad idea to change the trans springs as well, but you can get OEM type ride height adjusters on the cheap if you want to keep running the old trans leaf springs.
Sway bar end links last around 30K or hard driving before they need to be replaced (will become loose/worn and click).
Shocks last around 35K before it's really time to replace them as well.
As for at 100K (on at least your second set of the above), yes on just about every pivot point part linkage in the suspension not covered above should be replaced to tighten them back up, and stop the noise. Also, not a bad idea to change the trans springs as well, but you can get OEM type ride height adjusters on the cheap if you want to keep running the old trans leaf springs.
My ride height has never been touched and I have no issues with it. Could those be another noise maker? Do the ride height adjusters ever really wear out?.
I'm tempted just to replace all bushings and the ball joints while I'm at it. From what I've seen, there is no way to get OEM ball joints or control arm bushings and they only sell the arm and knuckles as complete assemblies.
I've seen aftermarket ball joints for significantly cheaper than the whole control arm, but I've not seen any replacement rubber control arm bushings available. Everything is either poly or delrin. This car is a 100% daily driver. I occasionally drive some back roads with some gusto, but I'm never really pushing it beyond my driving skill limits. The roads I drive are all relatively decent with the most harshness being on the elevated sections going over expansion joints and unions in the highway. I'm thinking I could live with poly or delrin bushings but have never been in a car with them on the control arms. At the price of the delrin bushings, it might make more sense to just buy replacement control arm assemblies. The poly bushings, reusing the original metal parts, are quite a bit cheaper and would lean towards keeping the arms and just changing the parts. Any thoughts?
If you have the upper A arms out to renew the bushes I would have the mounting holes slotted so that you can increase the caster to improve the straight line feel of the steering. You can’t get enough positive caster with shims alone.
I would spray all the rubber with at-205 and then start planning the replacements in a smart way to minimize labor and aligments. I do most of my own labor but taking it for an alignment every time i replace something really adds up. I am in a similar situation, car had 100k when I bought it in january and I'm trying to get it freshed up and tight.
Most of the big bushings were ok, but the endlinks were definitely toast and clicking. Replaced the links and new z51 sway bars first since they are easy. Then I did my outer tie rod ends which had torn boots, since I had to take them off when I did my harmonic balancer. Then I replaced the ride height adjuster which was sheared off and set them all even (lowest). Then I got an alignment.
I am not going to worry about creaky bushings until the next thing wears out or breaks, which I'm guessing will be the shocks. It has new mag rides up front and unknown mileage rears. The ball joints seem pretty stout on these cars as long the boots don't tear.
Just these new parts really tightened up the ride. Grips very hard with a new set of tires.
Since this thread was bumped, I thought I'd give an update. During the time between Christmas and New Years in 2021, I replaced all suspension components (upper/lower a-arms, knuckles, bearings, leaf springs, and tie rod ends with factory replacements except for the shocks which were Koni Special Actives. I had an issue with one of the Koni shocks about 6 months later where the double nut loosened and the shock fell out of the upper mount. Seems to be holding fine now for the last 2 years. I did have a lot of noise return about 8 months ago and tightening up everything seemed to have corrected everything, but I am hearing noise again that is likely the sway bar end links. I did torque everything to factory specifications too and had my alignment shop double check a few things.
Things I'd do differently? I'd get aftermarket sway bar end links. I'd go with a different shock than the Koni Special Actives. I like the slightly smoother ride, but hate the lower ride height. I've compensated with the spring adjusters, but still scrap more often than when I had the DRM Bilstein's on the car. I'd also bite the bullet and get either the racing SKF bearings or the normal SKF bearings at Napa that carry the lifetime warranty but still cost $300 a piece.
12-10-2018, 03:59 PM
Suspension noises @ 140k miles
So at around ~120K I bought four of the Moog K750136s when I swapped sway bars. Smooth and quiet ever since 
