help me track down a suspension rattle - Page 5

CLS70 · #1 02-29-2020, 12:12 AM

I went through a similar nightmarish front clunk chase ...... thought it was the radiator (clunk was replicable just with tap-braking), checked brakes/pads, radiator, engine mounts, etc etc etc

https://xoutpost.com/bmw-sav-forums/...tor-loose.html

After weeks of chasing the culprit, replaced lower control arms -helped but did not completely removed the clunk- I believe the issue is still the #8 part in the diagram which plan to address soon.

Baby Unicorn Taco · #2 02-29-2020, 08:15 AM

Quote:

Originally Posted by CLS70

I went through a similar nightmarish front clunk chase ...... thought it was the radiator (clunk was replicable just with tap-braking), checked brakes/pads, radiator, engine mounts, etc etc etc

https://xoutpost.com/bmw-sav-forums/...tor-loose.html

After weeks of chasing the culprit, replaced lower control arms -helped but did not completely removed the clunk- I believe the issue is still the #8 part in the diagram which plan to address soon.

#8 and #10 can create noises when they deteriorate. One thing I didn’t see mentioned yet is engine mounts. Worn engine mounts can creak and clunk.

Sent from my iPhone using Xoutpost.com

LightlyToasted · #3 02-29-2020, 08:41 AM

Would worn engine mounts clunk when tap braking, and over stutter bumps? My clunk is definitely coming from the driver's side. I'll see if I can get an inspection camera in there to take a look at it. I may also hook up a remote microphone to it.

In the meantime, I'm going to replace the hub/bearing assembly this weekend. I can make a fainter version of the clunk happen by quickly rotating the wheel back and forth, similar to tap braking. Previous microphone tests with a mic near the hub were very loud, but I've also learned that vibrations and sound travels through related parts.

CLS70 · #4 02-29-2020, 05:20 PM

I believe you replaced a number of items already but below are some posts with similar 'clunking' issues that I researched when I was troubleshooting mine.....there is great material here - just read through those.....

https://xoutpost.com/bmw-sav-forums/...left-side.html

https://xoutpost.com/bmw-sav-forums/...ks-x5-e70.html

https://xoutpost.com/bmw-sav-forums/...-hit-bump.html

https://xoutpost.com/bmw-sav-forums/...ssemblies.html

https://xoutpost.com/bmw-sav-forums/...end-clunk.html

https://xoutpost.com/bmw-sav-forums/...build-diy.html

https://xoutpost.com/bmw-sav-forums/...ive-drive.html

Several threads pointed to the #8 and #10 as primary culprits as well as sway bar links and the lower control arm - engine mounts was my "last" item to test (less likely to be the cause)

1. #8 and #10
2. Sway Bar Links (and Sway Bar Supports)
3. Lower Control Arms
4. Loose Brake Pads
5. Front Axle / Bearing / Diff.
6. Loose radiator
7. Engine Mounts

.....

ard · #5 03-08-2020, 07:42 PM

Did someone hear or BF drop a front driveshaft looking for a noise? Just for a few hundred yards, to diagnosis. deroy? Im thinking it was someone in the Netherlands....

LightlyToasted · #6 03-08-2020, 08:33 PM

The TIS seems to suggest that any play at all is bad. Mine has significant play, especially laterally and radially.

I wonder if I can rig up a GoPro in that area...

Badsmerf · #7 03-09-2020, 12:37 PM

Would that make noise when tapping the brakes though? All the U joints I've replaced were identified by vibrating or a single clunk, not from small bumps.

We might not have the same problem, but it sounds very similar. I haven't replaced all the bump stop in the strut/shock assembly, but have replaced the tension arm, end links and both doughnut bump stops. The sound started on the drivers side only, but it is now very much on both sides. I ignored it for a while, but I will be actively chasing it this spring. Hopefully you can find the answer before I have to go through a bunch of parts lol.

LightlyToasted · #8 03-09-2020, 01:04 PM

Quote:

Originally Posted by Badsmerf

Would that make noise when tapping the brakes though? All the U joints I've replaced were identified by vibrating or a single clunk, not from small bumps.

I can recreate the clunk by hand by rotating the front drive shaft through its radial play, so I'm confident that loading and unloading the drive train (via tapping the brakes) would do the same. As for the clunks caused by bumps, it clunks quite a bit by pushing it up and down (lateral play). I'll see about taking some video of this play.

At any rate, I'll know soon enough. In an effort to continue to throw money at this problem and single-handedly stimulate the economy, I'm picking up a front drive shaft today which by some miracle is in stock at a local parts store. The diagnosis procedure in the TIS is pretty clear about the u-joints not having play, so may as well replace this thing to see if it helps.

Ohsoslow · #9 03-09-2020, 05:08 PM

Would be great if you could put up some videos of the driveshaft play, ideally before and after.. I’ve got what I think it massive driveshaft play, so would be good to know if it is normal or not.. and If its the potential cause of a clunk I’ve got going on.

LightlyToasted · #10 03-09-2020, 06:51 PM

Quote:

Originally Posted by Ohsoslow

Would be great if you could put up some videos of the driveshaft play, ideally before and after.. I’ve got what I think it massive driveshaft play, so would be good to know if it is normal or not.. and If its the potential cause of a clunk I’ve got going on.

Got the part today. Hope to be able to install it tomorrow. Will take some videos along the way.