1966 230SL Rear Suspension

[Harry]

So just curious, if I wanted to freshen up the rear suspension on this car what parts should be candidate?  I have replaced the center bushing that mounts to the cross member in the trunk.  What about trailing arms bushings/rubber?  Shock absorbers?  And what is the experience in terms of results and improvement in ride, etc.

The car actually seems to be OK except there is a rattle sometime on the left rear over bumps.  Not severe, just there.

[jameshoward]

First, you'd want to figure out what the rattle is. It shouldn't rattle! It could be a host of things. In my case, the rear compensating spring was rubbing against the cross-member to which the fuel tank is secured.

The big central bush is a good place to start if you want to refresh the rubbers and is the easiest job. You could look at the bushes at the rear of the trailing arms, but from my experience they don't wear hugely (there's also the doughnuts at the front of the arms). It's not a small job and so replacing them may not be worth the effort. Any decent garage will be able to test your shocks on the machine designed for that purpose. Not much point replacing shocks that are perfectly good. They should be Bilstein, but I prefer the firmer ride of Koni Classics. You might also look at your tyres. If they're a decent brand and in good condition, fine, but old, cheap tyres could make the ride less good. There are rubbers at each end of the springs. Again, provided they're correctly seated and look ok, there's probably little gain in replacing them but worth checking.

There is a lot of rubber at the rear end. If you're taking out the springs to replace those rubbers, you may as well do the lot.

Personally, I'd focus on the rattle.

JH

[Harry]

Thanks James.  Good point on the shocks.  I'll know a little more when I get under the car.

[ja17]

Never had to replace the trailing arm rubber bushings for years (where they mount to the chassis). Now that these cars are fifty years old, seems like they are all going bad. Look at the condition of these first, since you already replaced the trunk mount.  Shocks can make noise when bad also. 

[Bonnyboy]

Its unlikely but check that the brake calipers are solidly mounted.   I had a rattle that would come and go and it was one caliper - before I bent the tabs over the bolts with the retaining plate. 

Not on my car but I have seen a trailing arm loose where it connects to the floor.

[Benz Dr.]

Anything rubber, seals and axle bearings. Not everything will need replacement but everything should be treated as suspect.

[stickandrudderman]

My view is that you should replace ALL suspension rubbers at the same time otherwise you are combining new with old and never really getting the benefit.

[ja17]

Yes, I agree with Stick, if your time and budget can take the hit. Refreshing all the rubber, seals and bearings is a good investment. The solid axle boot, and the horizontal, cylindrical, rubber/steel bushing are somewhat complicated to change. The bushing is pricey these days also.