Floobydust

Well, I'm at a turning point. I have been trying to exorcise the various vibrations from my Cab and I think I'm running out of ideas, patience, and money. I have/had the following bad vibs;

1. Engine vibration at idle - Solved with replacement engine mounts.

2. Under chassis "banging noise" - Seems to the the exhaust hitting somewhere. Not solved yet, but much better after straightening a few brackets.

3. Chassis flex (scuttle shake) over bumps. Still an issue, but somewhat better after the improvements below.

4. A come and go vibration at 60-65mph. I've done almost everything I can to try and get rid of this one. I have replaced the front lower control arms, the steering damper, the front struts & rear shocks (I'm back to the Bilstein comforts), the strut mounts (Meyle HD), checked on the tie rods, idler arm, and drag link (all good). I also replaced the motor mounts and checked the infamous "vibration absorber" which appears good. The tires are new Sumitomo HTR A/S P01's on 17" monoblocks. I have had them road force balanced twice to less 9 lbs on all four wheels. I have had the car 4 wheel aligned twice. Yet in spite of all of this, I still get vibration in the steering wheel and/or the rear at at 60-65mph. Some days it's worse than others, but always there to some extent. I spoke with TireRack and they are willing to work with me to change the tires if I want to go that direction (should I?).

I have inspected the bushing in the rear and the outer lower control arm bushings are so-so, but the rear camber is still spot on. One of the four subframe bushings has a slight crack in it, but overall they seem solid. The various rear links all appear okay. While I plan to get these, I'm not sure how much they are a factor in this problem.

I have enough money into the suspension & tires to have done the head gasket and wiring harness (which still need doing). I'm out of ideas (other than a good bottle of wine). This one issue is really keeping me from truly enjoying the car. Can anyone offer any other suggestions? If I can't get this resolved, the car will have to go which I really don't want, but this is one of those things I just can't live with.

Thanks everyone,

- FD

WDB124066

Is it a vibration or wobble ie a Hmmmmm or shake.

Floobydust

The vibration is a shake in the steering wheel mostly. If you let go of the wheel you can see it visibly rotate (shake) back and forth about 2 or 3 degrees each way. This is the typical front wheel out of balance or out of round type of vibrations (I know the wheels are good). Sometimes there can also be a vibration that you can feel in your seat too. Again, the typical wheel out of balance or out of round type of vibration one feels for the rear wheels. And again, I know they are good. After years of driving old British sports cars I know what drive line vibrations feel like and this is not that.

Thanks,

- FD

WDB124066

Couple of thoughts.....

Ball joints - need checking with a lever by someone who knows what they are doing. Did you replace the ball joints AND bushes when you did the LCA's Also the other steering joints should be checked with the car sitting as it does when it drives.

Brake disk run out, check with DTI.

Tyres, Wheel balance, you would be surprised how often the balancing people get this wrong. My guess it will be this. Look at the wheel as it rotates on the balancer. Go to the best balancer you can find, go where the new Porsche’s, Ferrari's and Aston's go. Get your wheels on a new balancing machine. Also check to make sure the balance weights do not get rubbed off by touching on suspension components. IT DOES HAPPEN!

Play in steering box. Check for correct friction torque can be done whilst it is in the car. Again this MUST be done by someone who knows exactly what they are doing and exactly as per the MB instruction.

RBYCC

I mentioned the brake rotors earlier on FD's "strut thread"...

Also mentioned the flex discs which may be the "banging" FD occasionally is hearing.....

I would check from the transmission tailshaft to the differential....

WDB124066

Yes!

Also, I have heard through other posters that the Sway Bar Bushes seem to have some effect on the symptoms you describe. I was surprised to hear this, I don't know from firsthand experience, but they are cheap as chips and easy to fit - on the front at least. Have you done these? Maybe put some fresh ones in up front and make sure the mounts for the SBB's are not cracked. This is a known problem with the 124. This could also be the source of the chassis banging you are hearing.

Check wheel bearings for play, although they have to be pretty bad for them to cause the wobble vibration.

Make sure ALL the vibration dampers are fitted to the car and are in good condition, the one on the windscreen and in the trunk.

Get your "Ball Point Position" checked between the pitman arm and the idler arm. There is a 2 mm tolerance on this and it just may contribute to the problem if it is out??


It is likely to be a combination of all these things to be honest.

Re the rear, these cars are known to be unstable when the rear bushes wear they twitch and wonder. They are past their best at 100,000 miles, at that point in time if you want the car spot on do them all, subframe, diff mounts and all 10 multilinks. It will make the car track straight and true instead of wondering a little when in a straight line, and twitching on cornering.


Have a close look at the mounting points for the front LCA bushes, I did hear they can crack here too, especially the trailing ones.....

spinlps

#2 did you replace exhaust hangers? Very quick and cheap, eliminated banging in my 4 w124s..

Steering wheel vibes, did you replace ca bushings? If so try installing at 90 degrees to normal position.

Or, steering gear frictional torque is off, set to 120 Ncm.


As you know I sold all 3 sets of my monoblocks (cinderblocks). I really liked the look but they are waaaaay too damn heavy and absolutely killed the ride of the w124s especially the wagon. I went with the lightest factory wheels I could find, 16" forged 99 clk's that weigh 13 lbs. instead of 28! A Freind has a tire shop and put on several sizes and brands of tires for me to try. I ended up with the Michelin Pilot Primacy 215/55/16 as best compromise of comfort, quietness, smoothness and handling to my surprise. Any wider or lower and the ride quality died.

I8NM5

Just ran through this with my S55 AMG. We did the motor mounts the tranny mount. Did many of the sma items you have (under warranty)
For me...Problem Solved. 20" staggered Vertini's with 0 Profile tires. Some freeways (Concrete with grooves) it just happens. The nice thing is it does finally go away...approaching 9D

WDB124066

Some reoccurring themes here FD. It will be sorted I am sure.

Floobydust

I agree about the cinderblocks although I see the effects mostly at the gas pump. The monoblocks have shaved at least 2 MPG off of my fuel mileage. This makes sense since it takes four times as much energy to accelerate a wheel that weighs twice as much. If I could solve the vibrations issues, the ride with the Sumitomo's and Bilstein Comforts would be ideal for me - just taught enough to have that precision Teutonic feel but not so rough as to be uncomfortable. I chose the Sumi's because of their very compliant sidewall - just the thing to counter the inertial effects of some rolling cinderblocks.

I did make some progress this weekend. I ordered some polyurethane bushings from energy suspensions and used them to replace the outer front swaybar bushings (I had to turn them down to fit). I did this because I noticed that the vibration would seem to come and go depending of the relative phase of each of the front wheels (e.g., go around a long sweeper on the freeway and feel the vibration slowly come and go as the relative position (phase) of the front wheels changes). Changing just the end bushings was my way of "connecting" the two front wheels (to cancel the vibration) without transferring extra suspension harshness to the car (the chassis mount bushings are stock). You can really notice the effect when you press down on the front fenders - the car moves up/down exactly level. And it really wakes up the steering response to boot.

This simple change has virtually eliminated the steering wheel shake although you can still feel the vibration in the "seat" of your pants, so there is still something amiss. I'm still working on it, but things are better.

- FD

WDB124066

Sounds very much like to me you have a wheel balance problem. Is there a top end wheel shop near where you live? Are your wheels round on the circumference. Do your side walls run true. Spin them on the car.

Floobydust

Well, that didn't last long. The vibration is back. Following up on the post by spinlps I located an MB document on "Programmed repairs" for the front axle. It seems that all the issues I have been experiencing were also complaints from others which resulted in changes.

First, I was experiencing the one-time "clunk" in the morning while backing out of the driveway. I thought it was the rear subframe, but it turns out that it was related to insufficient torque on the LCA eccentric bolts (see the PDF). I tightened my bolts, and viola, the clunck is gone. Interestingly, I noticed that the old left rear LCA bushing was loose when I changed the LCAs. Seems that what they say about the tolerance on the mounting bracket is true!

The other thing I noticed in the document is that MB had to change the design of the bushings to prevent exactly the problem I have been having! I found numerous posts about people chasing a "vibration" that turned out to be an issue with the LCA bushings (one person had to go to polyurethane in order to run 18" wheels). This prompted my to check my new LCA bushings and I discovered some interesting things.

First, according to MB, the rotational orientation is critical (again, spinslps noted that a change in orientation can make a difference). Second, the "hardness" or durometer of the bushings varies and is signified by the "bump" pattern on the bushings.

So I checked my old LCAs and found that both fronts bushings having a 1 bump/2 bump marking and the bumps are on axis with the LCA weld. The rear bushings have a 3 bump marking which is perpendicular to the weld, as would be expected from the MB bushing R&R procedure. I then checked the new LCAs on the car and found that things are really messed up! On the left side, the bushings seem to be rotated about 45 degrees from the originals (presumably, this means they are not seated correctly inside the LCA). On the right side, I found the the front and rear bushings are reversed!! Yes, they are backwards, as supplied, brand new. This means that the bushings are not located in the correct spot to provide the proper damping characteristics. Lastly, the new LCAs have a 1 bump bushing in the rear (if they were in the right spot).

So I suspect that the bushings are a major factor here. I had ruled them out because I had just replaced the entire LCA (because of the ball joint). Well, never, say never. The new parts are not correct. Gonna be having a little chat with Europartsdirect tomorrow.

- FD

BTW, does anyone have the submodel designation from the USA wagon (124.XXX)? I want to check if the LCA bushings are different versus the Cabriolet.

funkgab

oh god this sounds like my car
(my whole suspension is out)
not to threadjack but what kind of effect is there if your steering box is in play?
also how much did all the suspension parts with labor come up to about?

i may have an idea.. it can be a cracked rim perhaps? (curb damage, etc)
i know when i had a poorly repaired rim (still do but im using another rim for now)
after about 60mph it starts vibrating..

WDB124066

Well blow me down FD does it again. I am off to check mine!

Edit

Well, green car original front has 1 bump pointing down to the road and two bumps adjacent to the weld on both sides of the car
Rear bushes have three bumps pointing to the ground i.e. perpendicular to the weld.

Blue car has replacement arms and bushes and only the right hand side is incorrect. The bushes are the wrong way around i.e. fronts are on the back, and they assembled the front bush with the three bumps at 45 degrees to the road surface not pointing down to the road.

Seems you are not the only one to have suffered this FD, maybe why the blue car is less stable than the green, I thought it was my shocks!!

Ed, do you feel like having a check on yours? I'm guessing with such low mileage it is going to be a factory fit affair like my green car....

RBYCC

If it gets below a heat index of 100F, I may jack the car up and get my old bones under it....

WDB124066

I feel for you Ed, can't be nice in the heat. Get your bones down on that nice cool concrete, you can see them without jacking, a little mirror helps if you want to check them all........

Floobydust

spinlps -

Is there as easy way to do this? I looked at the location of the adjusting nut and the factory service procedure and they both point to a special set of wrenches to reach it. Any suggestions would be appreciated.

Thanks,

- FD

BTW - As an update, I finally re-bushed the right LCA which had the front/rear bushings reversed as purchased from Febi-Bilstein and I was able to rotate the left bushings into the correct orientation. I ended up re-bushing the right LCA because a check of other new LCAs found that they seemed to have the bushings in random places also (one was the same as mine, one had a front/read in each opening, etc.) The difference in feel and handling is nothing short of stunning. The car is back to that carved-of-an ingot-of-steel feel that the W124 chassis is famous for. Even the braking feels crisper. There is still a slight wobble in the steering wheel at speed (60 - 65 MPH), but you can't feel it if you have your hands on the wheel - you can only see it if you let get of the wheel. This makes me suspect that the steering gear center torque is too loose, allowing the wheel to move when it should otherwise be damped.

Floobydust

FYI, I took a couple of before and after pics of the right LCA compared with the old, but correct, left LCA which had the bushings incorrectly installed. I emailed these to Febi-Bilstein where I am sure they will just ignore it. But from my experience, W124 owners should not.

- FD