rear subframe bushings

[erubin]

Here is a picture of the part in question. I think it is called the rear subframe bushing. There is one on each side. I have several more photos in following posts.

1972 450SL

[erubin]

Here is the side view with the car on the ground.

[erubin]

Finally here is the side view with the car lifted and the rear wheels unsupported. There gap between the steel plate and the rubber is now 1/4". Does this mean the bushings are shot and should be replaced?

I have not experienced any clunking when going over bumps in the road and the car seems to handle OK although I have nothing to benchmark against. I don't want to perform unnecessary repairs

I imagine the bushings are hard to extract.

[300SDog]

Yep, pics #2 and 3 tell the story...... a verrry common problem. The worst I've ever seen amounted to metal/metal contact. New bushings will result in zero play.

Bushings are not expensive and replacement is an easy DIY project. Oughta start marinating frozen bolts today with penetrating oil. Soapy water will help seat new bushings, then you've got to retorque them after they settle. Rewards of replacement will be lessened road noise, smoother ride and zero pot-hole clunk.

[erubin]

Dieseldog,

Thanks for the tip. I just bought a set of mounts and spayed Kroil penetrating oil on the bolts. I hope its's not too tough pulling out the 32 year old bushings. MB shop manual recommends using a 10mm x 160mm mandrel to insert in the large bolt hole and then bearing against this with a 2 arm puller. The mandrel is not needed for 123 cars (I'm working on my 107).

[erubin]

I have a puller and a long steel 10mm dia shaft (mandrel) to pull out the bushing as recommended by MB shop manual. Unfortuanately i don't have a tool that will instal the bearing per MB diagram of the tool. Maybe if I just put soapy water on them (per 240dieseldog) they will slide in far enough so they can be pulled in with the bolt and some tempoarry installation washers. If the bolt is too short I hope I won't have to resort to pounding them in far enough until the bolt engages. Maybe a bottle jack can press them in?

I have to plan my job because it's my daily driver.

[Mark V]

when I did mine on my 114, I used 1/2-NC threaded rod and a big (like 2-1/2") black pipe cap. Drilled a hole in it for the rod to go through and pulled the bushing in. Make sure you pull the bushing in by the outer metal sleeve of the bushing and check the orientation of the bushing. I used glycerin to lube mine on the advice of someone here.

[JMela]

If the new bearings are too tight, you might throw them in the freezer for a couple of hours. Metal contracts when cold, so this might get you a little breathing room.

Anybody know the rear subframe mount pn# for 108's??

[erubin]

MarkV,

But 1/2"NC thread wont engage with the metric thread in the car. Did i misunderstand something?
The bushing installation rod you described must be screwed into the threaded hole that exists when you remove the bolt that normally holds the bushing in the frame.

Jmela,
Thanks for reminding me about using the freezer.

[rgnprof]

I need to replace these on my 114 - could someone tell me exactly what part (bushing) I'm looking for here? Thanks.

Ryan

Do the SLs have a different suspension than the SELs?
Thanks
Tim

[Tomguy]

Tim: Yes.
However, the 108's do have a rubber bushing between the frame piece and the arm piece - very similar in location and appearance to the attatched images.

However, I know not where to buy this (perhaps because I don't know its name?) I would like to - mine are SHOT!

[JMela]

Tomguy:

I'm assuming my 35-year old 108 rear mounts are shot as well. I'll let you know if and when I can come up with a p/ n for the 108 mounts. My dealership's been pretty good with bits I can't find online.

[JMela]

The corresponding part (#299 on this diagram) for 108 vehicles is 110 352 10 65 and lists at about $10.

Looks as though there's other rubber bits in the same vicinity to be replaced as well.

[Tomguy]

What about 252?
I should get under my car and look at it, it looks like a front subframe mount... I'm guessing this piece holds the center of the rear axle to the frame/body?

I'm guessing mine is flat, at best (torn at worst!)