rear coil spring upper rubber pads

[rmmchl]

I have an early 250sl . I went to the mercedes dealer the other day to check on the rubber pads that are on the upper and lower rear coil springs. They had 3 different sizes for the rear upper pad. size 30, 24, and 18 millimeters. I don't know which one. Does anyone know the correct ones to use?  I DO NOT want to change the factory ride height settings.

[Tyler S]

If you can remove an old one, fairly easy, sometimes the part number is still visible which will tell you what mm size. Or you can measure with a caliper or micrometer and then round up to the nearest size.

[rmmchl]

I do not want to remove them, until the mechanic is ready to change them. That would cost shop-down-time that would not be helpful,

[Shvegel]

They should be able to find them by using your VIN number.  My 280(no trunk well for spare like the early 230's) came with 24mm and remembering that 6mm is less than a quarter of an inch I don't thing you would be too far off the just order the middle ones.

[Tyler S]

There is really no way around this except if the dealer has all 3 sizes in stock and would let you buy 6 and return the 4 unused ones. The upper rubber pads are also used for camber adjustment depending on the adjustment of the bottom spring perch.
If there are still visible color paint marks on your springs (highly unlikely they survived) then you can use the table in the BBB along with the current lower spring perch setting to determine which size pads to use. All of this was determined at the factory different for each car depending on what options were installed. Power steering, manual trans, calif coupe, heavy duty springs,  etc..
My 250sl has 20mm pads but yours may be different.

[perry113]

Has anyone documented the easiest process to replace them?

[Tyler S]

Replacing them is fairly simple. You dont even need a spring compressor.
Raise the side you are working on with a floor jack under the axle. Add a jack stand under the axle, lower onto the stand and remove the wheel. With the axle on the stand (suspension loaded), remove the lower shock bolt and move the shock eyelet away from the axle. Next place a jack on a body jacking point on the side you are working on. Raise it just enough to take some of the load. Remove the large plate on the front of the trailing arm. Now raise the body of the car untill the spring is loose and remove it. Pay attention to the spring position and clocking. You can now replace the upper and lower pads. Use masking tape wraped around the pads and spring to hold them in place while re-installing the spring.

[Raymond]

Regarding the upper rubber thickness.  If you are in doubt, you can order the thinnest one (18mm) and then when you get the old one out, you can use the part number to determine what it was before age crushed it.  Then you can use rubber flange gaskets from McMaster-Carr as shims to make up the difference.  They are 5-3/8 inch Outside diameter and 1/8-inch thick.
The Mcmaster-Carr part number when I bought them was 9774K48.   They come in a pack of 6 for about $5.  I used one on each side. 

[Cees Klumper]

Just yesterday I removed both rear springs, in order to be able to turn the bottom spring seat plates each by one 'hole', so the car would sit just a bit lower in the back. Many years ago, I did the opposite, turning the plates one hole so that the rear would sit higher, not realizing that this one hole (there are three in total, so I moved them from the middle setring to the lowest one) would change the rear wheel camber by quite a bit, causing the rear wheels to not sit quite vertical.
I did the job more or less as Tyler describes, but without removing the large plates in the front of the trailing arms. Re-installing one of the two shocks was a bit tough and I had to use a long bolt plus a lot of WD40 to press it back on. Now the car sits right again.

[Cees Klumper]

P.s. My pads I am pretty sure are the original ones, and they're still in good shape. Yours may not need to be replaced?

[450sl]

your springs are colorcoded : refer to the BBB for the correct pads for your car using this colorcode.