Hi, I have a 1968 220D (W115, OM615 me thinks) with automatic transmission and unknown mileage (broken odometer). Most of the rubber on the car has failed, so it really needs new motor mounts, new front subframe mounts, and new rear subframe mounts. Assuming your car is similar to mine, I am trying to decide which jobs to do myself, and which ones to have a garage do. My local indy merc garage wants ~$1000 total for each of these jobs, with about 1/3 of that parts and 2/3 labor. I cannot afford to pay them to do them all, nor do I have time to do them all myself. So which could a moderate DIY'er tackle and which would you recommend I pay an expert to do. Thanks for the advice.

So here are the jobs:
1) Left and right engine mounts and transmission mount
2) Front subframe mounts
3) Rear subframe mounts and differential mount

The motor mounts and trans mount can be changed with minimal tools. Just need a floor jack and some various wrenches and sockets, and could be done in a afternoon. The subframe bushings are a much more work, and require a few special tool such as spring compressor and a press of some sort.

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I would suggest replacing the motor and tranny mounts and see if that cures whatever you are chasing. The subframe mounts usually don't cause much trouble.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

My '71 220D had a buzzing noise at speed, about 50mph, that sounded like the exhaust system touching the frame, with power applied. Foot off accelerator and the noise stopped. I spent a lot of time looking at the exhaust system, but it turned out the sub frame rubber bushings were collapsed. Taking out the 4 bolts was not easy, one of the front ones was bent. I was able to get them out, lift the car enough off the sub frame to get the bushings out and replaced, and that did the trick - quiet.

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1971 220D, daily driver, new paint, 142K
1973 220D, low compression
1975 300D, back on the road! 166K
1971 220D, salvage, rear hit, engine excellent
1972 250, bad cam, but runs!
1971 230, engine stuck
1971 220D, low compression, rusty
1976 240D, salvage, engine excellent
1966 230SL, water in oil after rebuild

Engine and trans mounts are not very difficult, but suspension bushings are a whole different realm of difficult. I have done the rear ones, its not much fun.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)