Subframe Mounts

[bpossel]

[:0]OK, finally got the nerve up to tackle replacing the subframe mounts.  It was a bit difficult, but was needed.

Plan on an entire day.  You will need the help of another person.  You will need all of the standard tools plus a couple of very large crowbars.  I ended up using a 30+ inch bar on the right side.

Attached are a few pics.  The pic below shows the old subframe mounts removed.  Sorry, didn’t take a side by side with old and new mounts on the bench.  If you have ever seen new mounts, you can see right away that mine had collapsed.

Below are 2 pics comparing the old and new mounts installed.  If you look closely, you can see a difference in height between the old and new.  The new mount has some very thin loose rubber...  looks like its peeling, but really no problem.  Looks like the entire mount was dipped in a thin rubber coat for storage.  This simply peels off.

I replaced one mount at a time.  Since I am in the process of also replacing the rubber on the top of my front springs, my front springs are removed.  Here is a summary: have both front wheels off; car sitting on two (2) floor stands at point of front jack points; one hydraulic jack under side of suspension that I am not working on; another hydraulic jack under the center of the subframe itself; disconnected the battery; removed the horns; removed the shocks; removed the CSV for easier access to the plate and bolts on right side; disconnected the brake lines at the calipers; loosened the leaf spring on the side I am working on; loosened engine mount main bolt of side I am working on; jacked up center of subframe, ensuring that tension is off; removed 4 bolts and cover plate; I did notice the mount shifting when I removed the last of the 4 bolts; removed large main bolt holding the subframe mount.  Now I carefully lowered the hydraulic jack that was under the center subframe.  Lowered a bit, stopped and checked that I wasn’t binding on anything.  Looked for tight wires, pinched hoses, checked that fan wasn’t getting caught in the fan shroud…  

Now the fun part.  Even with the subframe lowered as far as it would go, there still wasn’t enough room to simply remove the old mount.  I had to use a crowbar between the body and the subframe.  With a lot of prying and a few prayers in between a few other words…  I was able to squeeze out the mount from the left, drivers side.  The right pass side required the help of my son and a 30+ inch crowbar.  He ended up putting all his weight and muscle into pushing down on the subrame on that side in order to get the old mount out and the new mount in.   This side was more difficult due to the exhaust manifold and air-conditioning stuff.  I know that I was pinching the air conditioning hose and hope all is ok when I start and run it…

Once the new mount was squeezed into the mounting area, to reinstall each mount, I partially screwed in the main center bolt, again not all the way.  You need some play in the mount in order to be able to line up the 4 smaller bolts.  I then used a few screw drivers, punch, etc, to line up the 4 smaller holes.  I did raise the subframe at this point to get the mount to seat in a bit.  Then I screwed in the 4 bolts some more.  Then raised the frame all the way, as far as it would go.  Then finished by tightening the main center bolt, then the 4 smaller bolts.

A tough job, but I am sure that I will notice a difference in ride.  Wont know until next week.  Still waiting on the rubber for my front springs, so wont have the car on the road for another week.

Another note…  While raising the control arms without a spring, I noticed 2 small rubber bumpers located under each of the upper front control arms.  Mine are basically in pieces and not sure how what’s there is still hanging on.  I have ordered new ones from Millers.  Not sure what these do except maybe buffer the upper control arm when hitting some big pot holes?

If you are going to replace you subframe mounts and need some advice, just let me know…

Bob


Download Attachment: Old Subframe Mounts 1.jpg
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Download Attachment: Old1.jpg
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Download Attachment: New1.jpg
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bpossel
Memphis, TN.
1971 280SL
1997 E320

[Douglas]

Bob,

So I take it your front subframe mounts were original? What made you renew them? Were there any particular characteristics to how it was driving that called attention to them?

Also, could you summarize the rubber you've ended up replacing for the front end along with the part numbers and approx prices?

I think a lot of people, including myself, would benefit from renewing the rubber in the front suspension.

Douglas Kim
New York, NY
280 SL #016220

[bpossel]

Hi Douglas!

The reason I started working on the front end was that the previous owner had installed 2 spring nuts (cheater nuts) into the front drivers side spring.  When I removed the spring nuts, the front drivers side was approx 1 inch lower than the passenger side (as measured from the center of the wheel cover star to the top of the outer wheel well fender).   These nuts simply screw into the sides of the spring to keep the spring from compressing down under load.

When I drove the car after removing the spring nuts, I was amazed how much better the car seemed to drive.  Going over road bumpers was much smoother and car didn’t seem to wander on the highway.  I had an alignment done before going up to Joe’s this summer and will obviously have to have this done again.

In summary, I am hoping that with the new subframe mounts and new front spring rubber, my front end will be even on both sides and the car will handle as it did 34 years ago.  Hopefully...  it's not the springs. I really dont want to have to do this job over again...

I’ll keep you posted…
Bob

Here are the part numbers:
O-Ring Bushings for Inner Control Arms (Qty. MB PN 120-333-01-80 $33.00
Small Rubber Bumpers under Upper Control Arms (Qty. 4) Miller’s PN ? (on order)$?
Front Spring Rubber Seat (Qty. 2) Miller’s PN 220-200 (32-2002 number on invoice) $96.00
Subframe Mounts (Kit=Qty. 2) Miller’s PN 33-2001 $95.00
Rubber Bumper for Lower Control Arm (I had one missing) Miller’s PN 33-2107
Sway Bar Bushings (Kit=Qty. 2) MB PN 110-320-00-47 $106.00
Note: Already replaced rear rubber spring pads; trailing arm to body donuts...

bpossel
Memphis, TN.
1971 280SL
1997 E320

[rwmastel]

quote:Originally posted by bpossel

Since I am in the process of also replacing the rubber on the top of my front springs, my front springs are removed.

Bob,
You say that you hope the uneven height of the car is not due to the springs.  Since they're out of the car, can you have them tested anywhere?  I would think that someone would be able to put them under pressure and let you know if they both compress at the same rate.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[ted280sl]

Douglas,
  I had my sub frame mounts replaced last year. When my car was put up on a lift the from end just hung. Additional symptons include uneven front tire wear, a hard ride and noise transmitted through the worn out bushing. I suspect my bushing were exceptionally worn. The new bushing have made a major difference.
Regards,
Ted
1969 280SL

[bpossel]

Hi All!

Finished with the front suspension work today...

Recap:
Replaced all inner control arm bushings
Replaced subframe mounts
Replaced front spring rubber
Replaced rubber bumpers under upper control arms
While springs out, replaced left king pin & all bushings
Note: Replaced right king pin earlier this year; also replaced rear spring rubber and front trailing arm donuts

My front now sits perfectly even.  Here are the measurements (top of outer fender well to center to wheel cover star) and full tank of gas.
Before:
Front Left = 14 2/16
Front Right = 15 5/16
Rear Left = 14 8/16
Rear Right = 14 15/16
After:
Front Left = 15 9/16
Front Right = 15 9/16
Rear Left = 14 12/16
Rear Right = 14 1/16

Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[erickmarciano]

if the price fot the mounts are to cheap then you don't have the good one <like K-K > they do not sell the good ones they sell the 108 ones that are I think 1/4 to high. I put those on my car and it went ok but a little higher , they also don't come with the top metal plate



1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[A Dalton]

quote:Originally posted by erickmarciano

if the price fot the mounts are to cheap then you don't have the good one <like K-K > they do not sell the good ones they sell the 108 ones that are I think 1/4 to high. I put those on my car and it went ok but a little higher , they also don't come with the top metal plate



1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

 Yes... the 113 chassis takes the 111 330 14 75 , the 108 is
15-75.
 There is a set on ebay right now that implies for 113 , but they are 108.

[Douglas]

Bob,

So is the subframe mount identical when you look at it installed from the engine bay? I saw one in a Pagoda recently and remember noting that it looked slightly different. I don't recall the difference, but I think it was the black metal plate on top that was slightly smaller.

Douglas Kim
New York, NY
280 SL #016220

[erickmarciano]

the 108 does not give you the rectangle metal plate and the bolts that come with it are to short so I has to use the old ones

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[bpossel]

Hi Douglas,

The old and new sub frame mounts were identical.  Top metal plate, etc.. looked the same. The kit from Millers came with both mounts, 2 large center bolts and 8 new smaller bolts and lock washers.

Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[bjudd]

a pagoda companion pointed me to this link which has a few pictures and description  that I find helpful in contemplating the subframe mount project.

http://www.mercedesshop.com/Wikka/W108Subframe

thanks J.saylor!

bjudd
1969 280 SL 5 sp

[TheEngineer]

bpossel: Thank you for bringing the subframe mounts to my attention. I inspected them and found that any water which seeps down there cannot escape and I found rust. I also found that some P.O. had installed M8 bolts x 20 mm long, which engaged the thread only halfways. I cleaned things up and installed 25mm long bolts and the rubber pad which is called for to limit excessive travel. I found some threads a little damaged because the bolts were too short.

[jameshoward]

Hi Bob,

I'm about to launch myself at the engine and subframe mounts as mine are utterly shot. I have read your posts with interest and find them very helpful (if you've got any more info lurking out there, please do send it to me!! I have been waiting for a BBB and parts list I purchased off Ebay in the US to come for almost 2 months and still nothing; I don't suppose you still have your list of parts you used to replace all your rubber bushings and mounts?!!)

Anyway, as I'm putting the tools and parts list together, I was wondering if you used, or decided against using a spring compressor to assist you with this job? I don't think you make mention of one and I've seen them in the stores and on the net at affordable prices. Do you think they may have helped you when you were trying to lever in the various mounts you describe in the above post?

Any advice gratefully received!

James

[merrill]

A Dalton,
I ordered a sub frame set from az autohauz and received 113 586 00 33 in mm box .  I have a 66 230 sl.

could this be a new partnumber for the 111 330 14 75

thanks
matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[bpossel]

Hi James,

I didnt use a spring compressor.  I used 2 hydraulic jacks.  If I ever do any spring work again, I will purchase a spring compressor.  It would make the job a lot easier and safer!

Part numbers for all the various rubbers would take some time to put together.  Even then, it would not really be a good list of numbers because I ordered from various different suppliers, each with their own unique numbers.

Email me your e-address and I will send you some info that I complied from this site...
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[merrill]

so, heard back from gernold,
 113 586 00 33  is the correct part number for the 230 sl front sub frame mounts.

matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[blue230sl]

i have a '64 230sl chassis with a 250se engine.
to replace the sub-frame mounts , would i use the 230sl or the 250se mounts?

[waqas]

quote:Originally posted by blue230sl

i have a '64 230sl chassis with a 250se engine.
to replace the sub-frame mounts , would i use the 230sl or the 250se mounts?

You would use the 230SL subframe mounts.