What exactly constitutes the subframe components for the 83 300D Turbo?
Do you systematically replace them because of the age of the car?

id say its a good idea based on that it does affect alignment in the rear...
it is held in at three locations, the two main rear sub frame mounts two big bolts, and the rear yoke...at the diff mount - four little bolts...I did not catch where your are located before I started saying this...but the two mains can be aged in there and it is pretty hard to penetrate with oils...you have to soak and let capillary action do what it can...
hows the ride?
Jake

I just finished replacing some very tired rear subframe bushings on an '82 300td. The back end of the car was sagging slightly (half an inch) and the rear axle was clunky over potholes.

Raising each subframe arm with a jack, I saw significant movement of each arm before the body of the car began to rise. I also noticed that the center part of the bushing, which had seized to the mounting bolt, was stretching out from the part that is pressed into the subframe arm.

No amount of penetrating oil was going to budge the bolts from these bushings. On one of the bushings, I'd crank the bolt a quarter turn and the elasticity of the bushing would snap it back. The threads on the other bolt were also frozen to the chassis, but that's another issue.

After some intensive head-scratching, I dragged out some Bosch Roto-Zip Sabre-cut bits I had on hand. These are rotary tool bits that are made to cut through wood or drywall. I detatched the two small bolts on the spider covering and worked through it to carve through the rubber in the bushing. I turned the bushing bolt to rotate the spider, then carved some more, working around to all sides of the bushing. Eventually I cut the center of the bushing free so I could remove the big bolt.

With the spider, bolt and bushing hub on a bench, I soaked it with Kroil penetrating oil, heated it with a torch and pounded on the bolt with a 21/2-lb. masonry hammer to no avail. I eventually had to cut the bushing off the bolt with a cut-off tool so I could re-use the spider.

As for the diff mount, a bad one will produce enough negative rear wheel camber to produce wear on the inside edge of your tires.

HTH
Russ M

Hey,
This is very interesting. I was wondering the same thing. Nowhere in the Haynes or Chilton manuals does it ever mention "subframe". I always thought it was a difficult job from reading this tutorial:
http://business.baylor.edu/Richard_Easley//autofaqs/sframe.htm

I just now realized this is for the subframe mounts. Should the mounts be replaced with the bushings? How do you know if they are bad?

Now I'm thinking that the bushings themselves should be a fairly simple process.

Danny

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1984 300SD Turbo Diesel 150,000 miles

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Thanks for all the replies.
This car previously was in San Francisco and has been in Phoenix now for the last year.
I'm not sure I have all the equipment to do this, jack and all. How much do you guys think is should cost me at a shop?
Thanks.

Fro the subframe mounts this is more of a grunt type job not a special tool job.
You will need the normal jack stands and jack. socket wrenches and ratchet. A pry bar, any 18inch or longer will do. And some muscles.

Support the car on jackstands and unbolt the subframe bushings. Pry the subframe out from the mount area and I placed a old subframe bushing between the car body and subframe to keep it seperated. Pry the old bushing out and use silicone to install the new bushing. A longer bolt than Mercedes used and some spacers will help you reseat the new bushing. I welded a c channel to dothis but spacers will work. Get the bushing into position so that the mercedes bolt will get some threads. Torque it to specs and atttach the subframe components.
the manual shows quite a complicated aray of tools and methods. Its not this complicated. Just get the car on jacks and muscle the subframe out of the way. As always be safe when under a car. Proper jack stands are a must.

Noe the subfram mounts are not the complete erar suspension. Their are also the trailing arm bushings, A lot more work. And the differential mount, about like the subframe bushings. As I said the trailing arm bushings are the most difficult but doable.
So a search on rear suspension rebuild.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

http://www.mbnz.org/forums/forums/thread-view.asp?tid=1168796&posts=13&hl=rear+suspension

theres some pictures...it does show how hard it is to get oils up into the threads of the subframe bushing bolt....i think i was able to spray through to the bolt - or not...neverhteless it came free...not a bolt broke...

daves correct - its more muscle that anything...haviong some one help would be great...BE SAFE!

jake