Rear Suspension Bumper

[Harry]

That’s probably not the correct name but I’m referring to the rubber stop mount to the frame above each rear wheel.  When removing the old ones, three out of the four bolts snapped (arghh).

But interestingly, I find that there appears to be metallic “spacer” between the steel base of the bumper and the frame?  I swear it looks like it’s aluminum.  And, there is a gasket between the bumper and that spacer!  Can someone speak to what I’m seeing?

Harry

[Benz Dr.]

I believe you're referring to the zinc anode that's also a spacer. It's supposed to slow down rusting but I think it failed on most cars.

[stickandrudderman]

Known in sailing as a sacrificial anode.

[Harry]

Well, that's interesting!  Never would have even considered that.  So that explains why there is a paper (?) gasket between the anode and the steel bumper base?

[Ed Riefstahl]

Hi Harry,
I just had the same thing happen a week ago when getting the car ready to reinstall my axle.

I finally had to take an air cut off tool and cut the corner next to the bolt enough to pry under the alloy spacer which was very corroded as you indicate. After removing the spacer, the bolts almost came out with my fingers.

I have no idea where to get replacement spacers. This was one of those times I decided after some thought and research for parts, to clean them up and reinstall them. There is no real structural stress on them and Now that they're back in place, you can't tell, even if you were to crawl under the car and I showed you.

BTW, strapping a 2x4 to bottom side of the axle with tie down straps before lifting back into place was one of the best ideas I came up with. Not sure if anyone else has done this or not, but it made the reinstall a snap with one floor jack. A 2x6 would be even better.

The other thing I did after fighting with my store bought spring compressors, was to put hand made retainers on the coil springs while they were still on the car and under full car load, then removing shock and lowering the axle. Picture spring compressor clamps that are one pc. and don't have adjustment screws made from 1/4 inch stock. it took 30 minutes to make 4 of them. This allowed the springs to remain in their compressed state and easy to remove and put back in with new rubber.

I used two of the same retainers on the compensation spring. However I used my press to compress the spring about 2 inches from 14 to 12, which made all the difference to reinstall. This is a job that you need to know what you are doing for safety reasons. BTW, my press has a 1-1/2 inch vertical shaft to keep the spring from kicking out.

Good luck,

Ed Riefstahl
Erie, PA

1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1989 300SE (Majestic)
1999 BMW Z3 5 speed
1991 BMW 318I 5 Speed
1997 Toyota Paseo Convertible - Red 5 speed (have you ever seen one?)
1997 Ford Ranger (Step Side 54K)
2023 Mazda CX 5

[Harry]

Thanks Ed.

Very good information on the spacers!  I made a fixture that I had read about on the forum using a piece of 1" tubular steel to support the axles.  It fits across the shock mounts on the axle.  The big springs weren't a particular problem but that compensating spring is a bear.  I've removed it before and it was tough then as well.  I'd like to find one of the lower profile spring compressors that essentially consists of a hook welded to a long threaded nut on the threaded bar but I don't readily find those.  So I use a fixture that I put together, but it's still a pain.

Thank you again,
Harry