W111's slight inclination

[tempur]

Dear Forum members,

The following issue has me puzzled for quite a while now: I own a 1968 MB 280SEc (W111) which has so far done 30k miles. Since I've owned the car, the rear has been hanging, which I've been trying to correct by installing new rear springs, new bushings for the radius arms and, more recently, installing a new rubber mount for the rear axle carrier (the one in the trunk).
The car now sits at the correct height but only on one side. The driver's side is approximately one inch lower than the passenger's side.
Given the car's little use, I would not expect any excessive wear but rather suspect rubber mounts or bushings.
Any ideas from Forum members what could possibly cause this? The car looks great from one side but tired from the other!

Many thanks, as always,
Tempur

[sjefke]

Has the car had any damage on the driver side? Did you check the new springs to make sure they were equal length? I would have expected sagged spring(s) but you said you replaced them. How is the compensator doing?

Bert

[JMela]

There's rubber spring pads/ bushings (#15 in the image) in that may have gone south or disappeared altogether. They are available in different heights to fine-tune your ride height.

[Arthur Dalton]

Item 15 is for front spring mount.
The mount you want to be concerned with is #172. They come in different thickness and control the chassis heigth. However, if there is tweaking to be done from side to side on a Swing Axle set-up , then you turn the plate #180 to the next higher position. There are 3 different Index positions and that is the how you can balance both sides to equal. It is common to have the drivers side require a thicker pad or plate rotation to the next Index position b/c of constant driver weight. Specially in an single operator/ no passenger car.

[tempur]

Thanks for the advice. I'm going to see what can be done in terms of adjusting the ride. I take it that item #15 in Sjefke's reponse would do the same trick for raising the front part?
Tempur

[Arthur Dalton]

15 is front spring pad....the main difference from back/front is the front has seperate Camber ajusters at the kingpin upper joint...the rear camber is set by the combination of pad factors that determine the heigth , and then tweaked with spring plate rotational position.
So, the front camber can be set in situ, the rear can not as it has to be taken apart and measured. The rear axle should also be centralized as that also effects the difference of each side..that is done before other adjutments via the cross strut..the spec for that is Pivot pin is adjusted 36mm [ +/-2mm] to the right of the chassis C/L.

[tempur]

Dear Arthur,

When I replaced the central rubber mount (the one accessible from the trunk), the rear axle carrier was leaning heavily to the right after having removed the old mount. Only by re-adjusting to the right the jack holding up the axle was I able to center the carrier. From what you're telling me, I need to instruct my mechanic to make sure the rear axle is positioned in the center first?

Thanks for your helpful advice,
Tempur

[Arthur Dalton]

Well, a little more info.

That hanger has some adjusting cinch bolts at the pivot pin bushing/mount..this is at the BOTTOM of the hanger..what has to be done before anything is to make sure that the hanger is at a right angle [90 degrees] to the left axle tube before these cinch bolts are tightened at the hanger pivot bushing... The reason for this is b/c the left axle is part of the differential casing, whereas the right axle pivots. So this angle is critical to differential alignment.
So you want both axles level and the 90 degrees to the left axle tube before tightening. Also see if that bushing is centered with the pivot pin..if NO, then the rubber inside is shot and that effects both height and camber.

Here is a site that shows that 90 degree relationship. Click on the axle insert with the "I" code..that is for axle INFO.

http://www.sls-hh-shop.de/index.php/cat/c3_Mercedes-Benz-230-280SL--R113-.html/XTCsid/b3f70af9e9b9d139dd9d67059a7b436a#cat_121

Then you want to center the whole axle to the chassis Center Line..That is done by adjusting the cross strut. [ Axle Centralization / Pivot Bolt 36mm to the Right of chassis C/L]
I have a measure tool design in the archieves you can easily make to take the hassle of measuring from the Factory reference geometric chassis Bore Holes . All those measures are already calculated into my tools design.

If you can't find it , I will post it.

Here it is :

http://www.peachparts.com/shopforum/vintage-mercedes-forum/247534-what-control-repalce-4-5-rear-axle-post2140047.html?highlight=alignment+tool#post2140047

[tempur]

Thanks Arthur, this is beyond my capacities, I'm afraid, but will help me give proper instructions to the mechanic.
Tempur