What has gone wrong with my rear suspension????
 

1989, 260E, W124
A few months ago I had my front/rear suspension/steering rebuilt at about 250K
Rear: All bushings, suspension arms, and shock
Front: shock, one tire-rod-end, one ball joint and the steering damper. There is no problem with the front suspension.
But the rear suspension is very high. There is a gap of almost 4inches between the tire and the fender. All parts came from a Benz dealer (no aftermarket)
All suspension arms/bushing bolts were tighten-up with the weight of the car on the suspension.
Today, I had all those suspension bolts/nut loosen again and re-thighten. No change.
Could it be the shocks?" They are original dealer item (Boge)
Any hints?
JackD

I don't know what it could be EXCEPT the shocks.

jackd, Did you or someone else do the rebuild?If someone else did the work they may have put the arms in the incorrect location. That may change the height. I rebuilt a 1987 300D Front and rear myself. I changed one part at a time. Norm in FL

I would pull the part #'s off the front and rear shocks and check them against known correct ones. Try a floor jack under the middle of the front crossmember. Does the rear drop as the front goes up? If so, the front struts may be too short (e.g. Sportline).

Steve

Hmmm.... I was perusing the latest Performance Parts catalog, and it appears some 2.6's have the auto-levelling rear suspension. Does yours? If so, sounds like a simple height sensor adjust.

Steve

My 260E does not have an auto-levelling rear suspension or any other special parts (sportline, lowered etc).
The job has been performed by a former Benz dealer mechanic with 30 years experience on Benz using only Benz parts. He has been working on my car for 12 years and always done everything perfectly. He personnaly owns 4 different W124.
Since the job was completed, he dismantles and reassembled the rear suspension twice (no charge) to try an locate the problem.
He agrees that something's wrong.
Is it possible that some suspensions parts have been installed at the wrong place ? (I doubt it as I can't see which one can be mixed-up and installed)

This is probably not it, but on the W124, you can have different spring pads to adjust the height of the rear suspension. But by the sounds of it, it is most likely not this. This is quite strange since you didnt replace the springs. I would point to the shocks BUT I HIGHLY doubt they have enough pressure to jack the rear end up like that. hmmmm.....

I replaced the front shocks on our '91 and the front end definitely sat higher afterwards.

From the pic, the rear wheel definitely looks forward of the centerline of the wheel well. This might occur if one of the rear links was the incorrect part. Also look for collapsed subframe mounts.

Steve

I had an other session with my mechanic this afternoon. We checked for misplaced suspension arm. There is apparently no possibilities of mix-up. One part can not be installed where it does not belong.
All springs (4) are original and no pads have been added/replaced/removed.
Shocks; We disconnected the 2 rear shock. The car came down by about 3/4in. (Shocks are original type Boge)
Sub frame bushings: Still in very good condition, not collapsed or any visible deformation.
Very strange. Any other idea? My mechanic told be he'd do everything required to fix it (no charge) but he simply can't find what's wrong with it.
jackD

I doubt if it would be possible to get links switched and have them fit. You mighty be able to substitute a track link from a 201 for the 124 item, though, for instance. This might cause the sort of problem you have. easy to compare the old links against the new for dimensional variance.

It's gotta be something, right, and if you discount the unlikely, you may waste a lot of time if you've skipped over the answer.

Steve

Thanks for your reply.. I will not be able to compare the new links to the old one as they have been discarded. I have discussed the subject again with my mechanic this morning and he offered to come with me to our local Benz dealer, put the car on a hoist and spend as much time and money necessary to find the cause of the problem (at his cost).
Any other idea. If larry read this, I'd appreciate his comments. Thanks
JackD

Very Strange.
 

Gas pressurized shocks have about 75 lbs of lift each so new shocks raised my car about 3/4" as the old ones were shot. The shocks sound right. The ride height is determined by the springs. On the 107s there are 3 spring pad heights. Did you replace spring pads? I might check the spring seats. Does the suspension operate normally?

i'd have the parts dept double check the part numbers.
just because you're using mb parts doesn't mean your "friendly" parts dept didn't screw anything up. wouldn't be the first time i'm sure lol.

The suspension works normally, although I feel it is very stiff as compared to how it felt before having the work done. But, having everything new, maybe that is how it should be. Switching old/deteriorated bushings and shock absorbers to all new parts certainly contributes to the stiffening of the suspension.
Spring pads: Nothing has been changed from the original set-up. The original springs have not been removed.
There must be a solution somewhere
JackD

All rear suspension link bolts must be tightened with the rear axle horizontal, i.e. the rear axle must not be hanging down when the suspension link bolts are tightened.

The bushings in the supension links act as torsional springs and they have to be unstressed at ride height i.e. when the vehicle is set down on its wheels.

If the suspension is at its lowermost position (also called full droop position) (for example when the vehicle is lifted off the ground and supported by the four jack points on the chassis and the wheels are hanging down unsupported) when you tighten the bolts on the links, then that becomes its neutral position and when you let the vehicle down on its wheels, the busings get wound up and you have basically loaded the torsion springs. Now the torsion springs (i.e. busings) will try to react the load and go back to their neutral position which would be the full droop condition thereby jacking the car up on the rear.

Also, if the rear suspension link bolts were tightened with the supension in full droop, then all the suspension link bushings will prematurely fail since they are loaded all the time.

If you do a search there are a few articles that discuss how to support the suspension to get the rear axle to be horizontal befor tightening the bolts.

Good luck and keep us posted.

hs-300e

It was posted "All suspension arms/bushing bolts were tighten-up with the weight of the car on the suspension."

This is the mystery as to why the rear is still too high.

BTW, Mercedes measures ride height by the suspension component angle in relation to the body. It may make sense to see if the angles are within spec.

Having seen several German cars produced on assembly lines, they do get bounced several times before the suspension arms are tightened. It could be the case with your car that it needs to have the compenents unbolted slightly, the car jounced up and down multiple times and then rebolted.

Anther thought- did the recommended amount of shock bumper stops get install into the rear shocks when installed. It is not uncommon to get too many rubber bumper stops installed.

Haasman

Jackd,

The only thing I can see is if the mechanic is lying to you about tighting everything with the weight of the wheels on the ground. My car was WAY too high after a mechanic did the suspension rebuild - just like you rear end, tires not centered in wheel well. I did it myself a few months later and it was restored to factory ride height. My dealer has a Beissbarth alignment rack as level meter and the ride height measurements are spot-on to the 124 service manual in the front and with 0.5 mm in the rear. I have factory shocks for the car. When I rebuilt mine, I did not have the subframe on the car. I had it out behind the car. I loaded the subframe with the differential and axles and per the shop manual "axles are horizontal" so I jacked up the wheel carriers and then tightened everything down.

By the way, my wheels appeared off center in the wells when the car was too high. I'd say it looked exactly like your picture!

UpDate:
I and my mechanic spent over an hour at the local Benz dealer, trying to find what was causing the back end to be so high.
FOUND IT.
The rear shock abosrber supplied by the dealer to my mechanic were not the proper part number required for my car. On the 260E, there are 2 different shock absorber no., depending on the manufacture date. The parts guy (a new guy on the job) took the first number in the catalog.
Without even asking, the dealer replaced the shock absorber on the car (no charge) and offered my mechanic $100. for lost time and trouble. The car is now back at the proper height.
Not all dealers are stealers.
JackD

Congratulations. Always feels good when you solve the problem.

And if I may quote myself from the very first response in this thread, "I don't know what it could be EXCEPT the shocks."

;)

Your cheque is in the mail. :D

manny, money!!

Jackd,

Glad your problem is gone. Question, earlier message had you saying disconnecting the rear shocks dropped it 3/4". How much drop have you noticed since you have the correct shocks in there?

brewtooL You now can seat at the front of the class.:)
When we first disconnect the rear shocks, the can went down by about 3/4in. But we should have moved the car forward/backward for the suspension to set down to its normal level....which we did not do.
With the new (corect) shocks, the car now sits about 3in. lower than it did with the wrong shocks on.
According the the Benz dealer, it now sits 1/2in lower than the original specs, most likely due to some coil sping sagging (after 14 years and 300K.) wich is totally normal.
It was nice to have a mechanic that really wanted to fix the problem and a dealer that recognized their error (and paid for it)without having to fight a 3rd world war.
JackD

Thanks. When you first said they were disconnected I was looking elsewhere for a problem... going from Bilstein Comforts to dealer shocks on my car dropped ride height about 1/4-3/4". Your're right... Sure it nice to deal with people who want to make things right. I had to deal with a mechanic that installed control arm bushings incorrectly and tightened all links with the wheels hanging... and he wasn't interested in making it right. :mad:

joel

Please don't use that phrase, sounds like someone demanding alimony payments. :D

jackd,
when the ride height was corrected, did that also cure the wheel being in the center again ? how was the centered position for the wheel fixed ?
thnx.