Author Topic: Replacing Engine and Subframe Mounts  (Read 5267 times)

Valvechatter

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Replacing Engine and Subframe Mounts
« on: April 11, 2017, 15:32:20 »
I bought our 1969 280 SL in 2012 with the sole idea of keeping it for just a few years and then selling it. However, I find that I REALLY ENJOY this car and think that I will now keep it. I am just beginning research on replacing both the subframe mounts and the motor mounts. I have read the notes in the technical manual. I am sure that I will have many questions, but my first one is this: Is there a preferred (easier) sequence to doing these two jobs? Thanks very much!

Lin

Tyler S

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Re: Replacing Engine and Subframe Mounts
« Reply #1 on: April 11, 2017, 22:15:19 »
Doing them at the same time does make it much easier.
With the car off the ground supported by the body, Support the engine with a floor jack and block of wood. Remove the 2 large motor mount (17mm?) bolts. Raise the engine slightly being carefull of the cooling fan. This gives you a bit more access to the right side subframe bolts under the intake manifold. Next support the subframe with a jack. Mark the position and remove the 4 front leaf spring bolts. Next remove the 4 bolts at each subframe plate. Remove the plates and then remove the large subframe bolts. Slowly lower the subframe just enough to remove the subframe mounts. Be mindfull of the brake hoses, dont stress them. You may need to wack the subframe mounts with a hammer to break them loose. Remove and replace the subframe and motor mounts. Reverse order for assembly.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

Shvegel

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Re: Replacing Engine and Subframe Mounts
« Reply #2 on: April 12, 2017, 02:19:08 »
Buy the subframe mounts for the same year sedan (280 SE).  You won't get the little black bump plates that you see from the engine compartment (Yours are fine) but you will save hundreds of dollars.

Valvechatter

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Re: Replacing Engine and Subframe Mounts
« Reply #3 on: April 12, 2017, 11:34:33 »
Thank you Shvegel. I will look into that. Tyler S. Thank you as well. Me thinks that you have somewhat oversimplified this job with your explanation :-). I think I recall reading someplace that one should do one side and then the other, rather than dropping the entire unit. Is that correct? I would love some more details about the process and photos would be wonderful. Anyone have any? Or can you give me a reference to a previous thread? Thank you!

I have brand new Bilsteins so the problem isn't the shocks, but when I apply brakes the front of the car kind of "nose dives" suggesting to me that either the motor mounts or subframe mounts are shot. Any opinions?

Thanks.

Lin

UJJ

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Re: Replacing Engine and Subframe Mounts
« Reply #4 on: April 12, 2017, 12:23:04 »
Don't buy after marked mounts, or you have to do it again in a couple of years. MB Parts only!
Urban
Urban Janssen
Grass Valley, CA
1968 280 SL - 4speed manual
173 anthracite grey

Shvegel

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Re: Replacing Engine and Subframe Mounts
« Reply #5 on: April 13, 2017, 10:13:56 »
You might be trying to fix something that is inherent to the car.  The "nose dive'" you mentioned is something that gets talked about here quite a bit.  Search here for "nose dive" and also do a Google search.  Accepted wisdom is that the solution is to install springs sold by John Olson.  He sells both progressive rate and sport springs.  Recently he recommended sport front and progressive rear to someone here.  If you search "John Olson" here I am sure there is a bunch of stuff on him as well.

http://www.slmarket.com/custom-springs-for-your-mercedes-benz/

Tyler S

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Re: Replacing Engine and Subframe Mounts
« Reply #6 on: April 13, 2017, 14:19:21 »
You can try doing one side at a time but because your doing the motor mounts at the same time, you really need the extra room having the subframe lowered down a bit.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)