Motor/Engine mounts

[Jazn]

Have a question about new motor/engine mounts.  The old mounts I took off the subframe (original) had a bolt coming through the bottom end and a plate that was underneath the motor mount.  The new one I received does not have this bolt or bottom plate, just two bolts to mount to subframe and a bushing to go underneath in between subframe and mount.  Should I try to take the old bolt off the old mount and put it on the new one?  I am not sure of it's function as it didn't secure the mount to the bottom of the subframe at all.
thanks
Jason

[George Davis]

Jason,

yes, remove the bolt and plate and install it on the new mounts.  Use some loctite, too, the bolts can loosen and fall out into the subframe.  The purpose of the bolt and plate is to resist pulling the mount apart when the engine torques.  As the engine twists, it compresses one mount but tries to pull the other one apart.  One of my old mounts came out in two pieces; the bolt and plate had fallen into the subframe.

George Davis
'69 280 SL Euro manual

[Jazn]

George
Thanks much for your reply.  I received a bushing with my new motor mounts, does this go between the motor mount and the bottom plate?  If so, that leaves a 4.6mm gap between the two.  Is this correct?
Thanks again for your input, really helps me a lot.
Jason

[George Davis]

Jason,

the SLS site shows how the mount is assembled (see http://www.sls-hh-catalogue.de/bin/dbframes.phtml?mid=IN02).

From top to bottom, you have the mount, the large metal plate, the rubber bushing, a washer, and the lower bolt.  No gaps anywhere.

George Davis
'69 280 SL Euro manual

[Jazn]

quote:Originally posted by George Davis

Jason,

the SLS site shows how the mount is assembled (see http://www.sls-hh-catalogue.de/bin/dbframes.phtml?mid=IN02).

From top to bottom, you have the mount, the large metal plate, the rubber bushing, a washer, and the lower bolt.  No gaps anywhere.

George Davis
'69 280 SL Euro manual

Ah, that clears it up quite a bit, I have the early style mount, little different set-up.  The mount I bought has the bushing for the late style mount, luckily I had the left-over bushing and bolt from my old mounts.
Thanks for all the help!
Jason

[merrill]

George,
I have 2 follow on questions.

1. according to the mb manual there is a distance between the stop plate and the front axle support.  in the chart the dimension for the 230 sl is 2. is this 2 mm?

" install the stop plate and the rubber spacer.  screw the collar nut down as far as it will go.  compress the rubber mountings in a press until there is sufficient distance between the stop plate and the rubber spacer.  then screw in the coll are nut 2 turns and lock by means of the hexagon nut.

note: this load on the rubber mounting is necessary to prevent torsional stress and damage to the rubber spacer when the collar nut is turned."

2. are the nuts for the 2 hex bolts welded to the subframe or will they drop when unbolted?

thanks
matt

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

[George Davis]

Matt,

on 1. I don't know.  From the directions you printed, it sounds like the rubber is compressed temporarily to allow tightening the collar nut without distorting the rubber - which suggests the nut would contact the rubber if it weren't compressed, so no gaps

On 2., yes, the nuts are welded in place (at least on the 280's, I assume they are on the earlier cars, too).

George Davis
'69 280 SL Euro manual

[merrill]

george,
well I thought I was going to be able to answer the questions regarding the motor mounts for a 66 230 today.

when I pulled the old mounts from my car, I did not have a rubber washer, lock nut or threaded bolt.  I did  have a metal plate, large rubber bushing and a bolt that was threaded on the end.

I installed the new mounts using the old hardware the way they came out and e-mailed gernold at sl tech to find out if I can leave it as is or not.

Pls see attached photos

Download Attachment: config as it came off the car.jpg
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Download Attachment: mountin hw.jpg
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Download Attachment: mt in car.jpg
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Download Attachment: old and new side by side.jpg
44.42 KB

Download Attachment: rubber bushing.jpg
31.45 KB

Download Attachment: top of old and new mount.jpg
44.87 KB

Download Attachment: under side of old and new mount, old still has hw.jpg
33.85 KB

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

[merrill]

Well, after skimming this post again, and going to the sls web site, I guess I have the late style mount.  

I will order a rubber bushing from k&K monday.

matt

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

[hands_aus]

hey Matt

What sort of digital camera are you using to take the pics?

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[merrill]

Bob,
actually it is an attachment for my pda.  there is no focus so I need to be careful to make sure I snap a good shot.  It has limited abilities.

matt

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

[George Davis]

Matt,

in your old and new pic, I think the new motor mount is incorrect.  It might be the rear motor mount that goes at the rear of the transmission?  When I replaced my motor mounts, the new ones looked much like your old one, not very tall.

George Davis
'69 280 SL Euro manual

[merrill]

George,
well, the old mount in the photo, was the bad one, the other one was just about the same height as the new one.  maybe half as short.

The mounts came in a MB kit in an mb box.  2 mounts, 2 rubber washers, 4 allen bolts and lock washers.

I thinks I just had one mount that was collapsed.

matt

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

[waqas]

While I'm doing some other work in the engine bay, I decided to replace my motor mounts. I thought I'd post some pictures comparing the old mounts to the new ones (since people are always wondering what to look for if their mounts need to be replaced).

http://www.sl113.org/forums/uploaded/Waqas/200742033631_engine-mounts-compared-1-small.jpg

http://www.sl113.org/forums/uploaded/Waqas/20074203375_engine-mounts-compared-2-small.jpg


WAQAS in Austin, Texas

[waqas]

Forgot to mention-- the stop-plates were missing when I removed the old mounts. It looks like there are many shops that simply throw away the attached plates/bolts along with the old mount, while replacing the mounts, not knowing their true purpose.

Incidentally, I was discussing the plates with a fellow car nut (from Munich no less), and he mentioned that these stop-plates may also have been placed there for preventing the engine from flying off during an accident. Ahhh... good old German engineering.... must protect precious engine... but seat-belts for the human... who needs 'em!

WAQAS in Austin, Texas

[merrill]

so, I think most of this confusion is due to the parts suppliers only selling the top mount rather than the mount kit.  FOR later models.

(Arizona autohauz sells the correct mount kit for the early set up.)

Gernold had told me the mb part number (which I forogt) for the correct mount kit.  The correct kit comes with the top mount and the lower rebound buffer. Ray at buds benz is looking up the new part number and I will post it later today.

we all know now that most part houses sell the upper mount separately and not the kit.  
The lower rebound buffer part number is 121 987 03 39.

I received one from cheryl at K&K and she hs one back ordered for me.
I also know that she has ordered 4 extra to put on the shelf.

get em while you can,  

matt

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

[merrill]

so,
per ray at buds benz the late mount kit part number is 110 220 02 17
this is 2 upper mounts and the 2 lower rubber buffers.

the attached photo (left side) shows the early and late mounts and their set up.

Download Attachment: mount,jpg.jpg
40.65 KB

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