Suspension/Steering Knock...driving me crazy.

Spent all morning working with the Chassis Ears. Definitely needs some patience to use it...

First, I attached to tie rods, the body of the steering rack:
> you could hear it in the background, but the "sensitivity bars" on the device did not reflect any noise.

Second I attached to the front driveshaft case
> Louder, but the sensitivity bars did not reflect much.

Third worked with the lower ball joints on both sides.
> Even louder, but still felt like it wasn't the part.

Fourth attached to the front subframe (near where the subframe bolts are).
> Definitely louder! Thought I had found it and was possibly front subframe mounts...

Fifth, I wanted to be 100% sure I attached on the subframe next to the rear-most lower control arm mount
> VERY Loud!!
Went back and this time attached the probe directly to the lower control arm bolt.
> Same volume, but the noise was much clearer and more precise sounding.

Got under, and the rearmost passenger lower control arm bolt was not fully tight. I went under and retightened to 110nm. Essentially 90% solved!! Still a noise small knock though...

I say 90% because after I rechecked all lower control arm bolts and torqued to 110nm, there is still a knock, but its very slight. Now that I am no longer getting an overpowered creaking noise, I can focus in on this. The knock, now seperated from the LCA bushing noise, sounds to me like it could be the sway bar bushings. That will be easy to isolate.

I can probably be very clear that the WIRELESS version is superior to the WIRED, solely because of the sensitivity bars. It picks up background noises, but unless the vibration is on the clamp, the sensivity reader won't spike, so you know the noise is not very close. I think that made a big difference figuring it out.

Well I’ve spent a good number of hours with the chassis ear...I believe the noise is still coming from the lower arms. At first I thought it could have been the steering rack, but the probes attached to different parts of the rack yielded no clunk, although the noise was still audible in the background.

I need to build a wheel platform out of 2x4’s to gain some more ground clearance since I’m unable to get my big torque wrench in on the lower arms with my regular ramps since the weight needs to be on the ground when tightened.

The LCA’s are 110nm torque...

My car came with ONE single adjustable control arm bolt and I ordered the stock unadjustable bolt since I’d like to return back to factory now. I will keep the old one but with the camber on both sides looking good now it’s not needed.

The chassis ear has been a great tool to eliminate parts.

It’s frustrating to me the noise is STILL seemingly coming from the LCA’s (both sides...). The arms were both new 15k ago and noise started 5k after I installed them. I find it incredibly unlikely both arms failed. The rubber visually looks new still.
Makes me feel like somehow it’s not torqued even though it feels like it’s tight enough. But can’t be 100% until I can get the torque wrench on it. I tried to hand tighten to match the lug nuts, but who knows.

Continued saga....

Decided to get a better look at the lower control arm bushings again. I think another silly mistake due to originally torqueing the LCA bolts while in the air...



The GOOD thing is that I already have the Genuine MB lower arm/transverse bushing kit in my parts box! I bought it originally 3 years ago, then when I realized it didn't come with the bushing where the strut attaches, I bought the entire A-arm instead and figured I could resell the kit (which never got any luck!).

This is on the passenger side, which according to my ear, is the quietest side. I'm betting the driver side bushing is even worse and hopefully this is the noise!

Going to get both arms removed and see if I can get the bushings out and new ones pressed in with adapters I have in the garage, otherwise I'll have to buy a tool.

Ok update!

Driver side bushings were OK, passenger was pretty worn. Replaced both.
I ended up buying the KTC tool to press the bushings back in, which worked great...one caveat though is that the tool is really designed for the W210. I also used an adapter from the Astro Master Ball Joint kit (the black adapter used in press photo).

https://www.amazon.com/gp/product/B00061SGPO/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1


Removal of the two smaller bushings is best done using a punch on the edges. Work it around until it comes out, or work around enough that it has come out a little, then a few big whacks from the back and it comes out.






Installation orientation is important!! The longest side of the bushing must be 90 degree's with the LCA. In addition, there is a gap in the bushing that must face the chassis...In all there is only ONE correct position, don't get it upside down. I took photos of the bushings before removal to be sure I put it back the same way it came out.





Got it all tightened back up (tightened bolts after backing the car off the driveway, and back up to be sure the bushings settled in their driving position) and so far no noises, however I said that last time and then after a few more miles it came right back. Will update in a few days!

Well you can't say I didn't nail it!! Prior to going to the local shop /w a hunter alignment machine, I fully filled up the gas tank and pressurized all tires to spec.
Dead perfect up front! I think that probably wraps up this saga now

Prior alignment (last time aligned in 2016) when I realized something was off:


Alignment this morning:


Can't really know for sure if the rear camber change if related to gas tank fill (no idea if it was full or not in 2016) and how it was loaded, or if a sign of minor wear, but not concerned since no odd tire wear patterns.