I went over a really bumpy road the other day, and now I the rumbling going over bumpy roads - the sway bar links seem tight and I can't feel any play. Anyone make a bet which one it is below so I can start with the most likely stuff first. Seems like it would be a blown rubber bushing?...do these actually 'leak'?

Anyways, all guidance appreciated! Many thanks.

From the TSB - my comments in bold

Model 203.040/061/064/065/261/264/740/764

Rumbling Noises While Driving Over Bumps or On Bad Roads

If you receive customer reports in the above model vehicles of rumbling noises while driving over bumps or on bad roads, please refer to the below possible causes / remedies. Experience has shown that knocking or thumping noises from the front axle has nothing to do with the lower cross strut or the suspension strut.


Cause 1:
The rubber mount on the torque strut is cracked and losing fluid. Affected vehicles are up to VIN A436252 and F339810. - what is a torque strut?

Remedy:
Replace the rubber bushing only. Refer to WIS document AF33.15-P-1120BG. - how big a job is this?

Cause 2:
The drop links of the torsion bar may have too much play due to corrosion. Affected vehicles are up to VIN A449884 and F352398 - will they be easy to wiggle if they are shot? - what part fails on this?

Remedy:
Replace the torsion bar drop links. Refer to WIS Document AF32.20-P-1105AG.

Cause 3:
The rubber mount of the torsion bar has too much play and is worn out. Affected vehicles are up to VIN A407163 and F311913 - this is the sway-bar where it lays in the rubber that is held against the sub-frame by c-shaped shackles?

Remedy:
Replace the rubber mount of the torsion bar. Refer to WIS Document AF32.20-P-1001AG. - or get an H&R sway bar

Cause 4:
Excessive play in the torque strut joint, which may cause knocking noises. Affected vehicles are up to VIN A098943 and F070099

Remedy:
Inspect the torque strut joint by raising the vehicle on a chassis lift so that the wheels are not under tension. Manually move the torque strut in a vertical direction up and down in the vicinity of the ball joint while looking for play. If play is present, replace the torque strut. Refer to WIS Document AR33.15-P-0160P.

Cause 5:
The distance between the rebound stop and the rubber mount for the shock absorber strut is too small. Affected vehicles are up to VIN A072536 and F049970.

Remedy:
Check the clearance between the rebound stop and rubber mount on the shock absorber strut.

The clearance must be between 1-2 mm. If there is not enough clearance, replace the rebound stop. - I don't think this is me as I just put in lowering springs and this distance when up I think

Refer to WIS Document BA32.25-P-1006-01B.

 

It is understandably difficult to diagnose untoward noises on the forum.

I’ve suffered some distressing noises from up front. Each solution to date has restored and improved upon its as-delivered driving experience.

* Tie rod ends replaced.

* Anti-roll bar to frame bushings. Replaced when H&R bars installed.

* Bar-to-strut links replaced when they failed from the additional loads.

* Spring hats and bump stops replaced when H&R springs installed.

It’s quiet for now, but I’ve thrown some parts at it to get it that way. When most recently under the front end, during my bi-xenon installation, I noticed the torque arm bushings were losing their jelly filling. Evidence of their leakage is patently obvious. Yes, they are liquid filled. I’m fixing to replace them soon. I’ll post a DIY. Alas, that will be of no help to you today. This link – https://mbworld.org/forums/c-class-w203/186284-tie-rods-worn-out.html may prove helpful. For a track aficionado such as yourself, take note of smgC32’s threads. He replaced his with K-Mac (solid) bushings, at the expense of NVH.

Another MBWorld member has my service DVD. When it’s back in my possession, I’ll PM you the relevant torque arm information. Regretfully, its contents cannot be posted here due to copyright issues.

*off topic*

BTW Bif, I wore a tidy Reyn Spooner for last Sunday's MBWorld meet. https://mbworld.org/forums/c-class-w203/199172-mbworld-meet-crashers-updated-more-pics.html

 

Oooh, that is tidy

Good link - more or less confirms the TSB information. Thanks!

 

Remedy:
Replace the rubber bushing only. Refer to WIS document AF33.15-P-1120BG. - how big a job is this?

a 2 hour maximum job. not a big deal..however. have you checked your wheels to make sure they aren't bent? just a simple fix maybe.

bah n/m u said it was on bumpy roads..