Transmission Mount Installation

[col320ce]

I've just installed the transmission mount on my manual 230SL ... but the only thing I was not sure about was how much to tighten the bolt that comes from above and screws through the transmission mount.  On the engine mount, from memory, it needed to be finger tight then tightened another 2 turns. This one needed 4 turns to get enough bolt thread through the mount. My setup was similar to that of the exploded diagram attached but I'm not sure if this is correct for the W113??
Any thoughts?

[450sl]

You might want to outline your transmission drive , this can be done with shims.

[ja17]

These early cars are the only ones with the long through bolt. Care must be taken so as not to over-tighten and collapse the mount. Carefully watch to see when the mount just starts to compress, then lock it down. I cannot find an actual "turn spec" in my Early BBB.

[Charles 230SL]

hello ja17, thought I'd revive this thread because I still don't understand how the capture nut I refer to in a later string (https://www.sl113.org/forums/index.php?topic=23157.0) locks the through bolt.

I've got an early 230sl (long through bolt) and I don't see where there's room for a capture nut between the mount and the bottom plate. Would you happen to have a picture showing where the capture nut is placed? Can a regular threaded nut be used instead of the capture nut? many thanks, Charles

[wwheeler]

Since this mount is very similar to the 220SE W128 rear engine mount, I just recently replaced that and have a recollection in regards to the long bolt adjustment. In the "starting 1959" service manual, it goes over the "A" dimension. A similar "A" dimension is on the diagram for the trans mount that is found on the link that Charles provided. Again it is similar to my rear engine mount adjustment.

The long bolt has a rubber washer under its head. In theory, that rubber washer should not contact the mount and should have roughly a 1mm gap. You cannot see that gap because of the rubber cover. That is why they give the A dimension below and when set to that, provides the correct gap between the rubber washer on the long bolt and the mount. This mount is normally in compression, so the long bolt is there just to restrict movement if the mount is in extension so the mount does not pull itself apart. Shouldn't happen often, but that is what it is there for. If the mount does become in extension, the rubber washer cushions the contact between the mount and the long bolt head. 

[Charles 230SL]

Thanks Wallace,, I think I'm finally starting to get it.  In his post further below, when Joe says "..watch to see when the mount just starts to compress, then lock it down", he means to lock it down with the bottom hexagon nut (#19).

I'm still not certain what item #20 is and I notice it’s not labeled in the diagram.  If it were a spacer it would need an elongated center to accommodate the bottom of the rubber mount (see pic). If it's used on a W113 I'll add it to my MB parts order. 

[wwheeler]

Yes, #19 is a lock nut because of the metal insert in the mount is also threaded. So the bolt threads down into the mount's metal insert and when it is adjusted at the correct height, lock it down with #19.

I am not sure if the bolt should be adjusted far enough down so it actually compresses the mount or not. Considering its function, I would think that the bolt should be adjusted to the compression point, and then backed off maybe a 1/2 turn. That would allow the rubber mount to remain flexible to absorb vibrations. Compressing it even slightly would seem to reduce its ability to dampen vibrations. I don't think it is a critical adjustment though and Joe has more experience with this than I will ever dream to have.

[mBdrvr]

I just replaced this on my W111. The W111 is different but the point is to turn down the large bolt until distance "a" is achieved. This puts the proper pressure and leeway on the top of the mount. Distance "a" can be found a page or two before the mount instructions in the BBB.

[Charles 230SL]

Wallace/Paul, thanks I really appreciate your help.

I hate to belabor this topic but I'm still trying to figure out what item #20 is.  I can’t find a picture of it anywhere but in the diagram it appears to be a spacer that's ‘keyed’ into the elongated base of the trans mount.  Does a W111 or W128 have such a spacer?

I'm trying to put together a comprehensive list of all the hardware/rubber parts that comprise a transmission mount for an early 230SL (my 230SL is missing them all) and I only lack the part number for item #20. If I had a MB part number for #20 I could go ahead and order all the parts. I hate to get halfway through a job only to find I'm missing a part - and have to the wait a week for it to arrive. we've all been there...
 

[66andBlue]

Charles,
here is picture of the parts listed in the spare parts list for early 230SL.
If you can figure out which part it is that puzzles you then I can look up the part number.

[mBdrvr]

It appears to be the "spacer ring". This allows the adjustment of the height of the transmission above the support. I used some washers. There is another thread about the relationship of the trans output, the donut between the drive shafts and the rear end. This is supposed to be a straight line, adjusted by the spacer.

[Charles 230SL]

yes, it makes sense that it would be a 'spacer ring' so it looks like it would be item #38 in Alfred's post.
 
I knew spacers with varied thickness were used to align the drivetrain, but I never realized they were so large in diameter. Alfred, if you could find the part number for #38, I'll go ahead and order a couple. If there's an MB part number for the hex nut #40 would you mind providing it too? i owe you guys, thanks,,charles   

[66andBlue]

Here you go: #38 = washer p/n 186 990 46 40; #40 = p/n 000936 012006 = translated: hexnut M12 DIN 936
 

[wwheeler]

Charles,

I just looked at the EPC for 230SL and under engine suspension. It is very confusing. It is possible that MB has decided to make the original set up obsolete? Niemoeller has some parts on their list and some look like different thickness washer. Maybe that is what you are after.
https://www.niemoeller.de/en/w113/w113/B042/220/

SLS seems to have the thick washer as well but indicate the 230 SL has two different mounts. https://www.sls-hh-shop.de/main/en/mercedes-230-280sl-w113-/22-enginemounts

See what you think.


 

[66andBlue]

Wallace,
indeed there were differences between the early and the late 230SL mounts. But SLS got it wrong.
Charles has a 1964 230SL and for that car the mount picture from the Edition B of the spare parts list that I posted earlier is the correct one.
In Edition C that picture changes and now one can see 3 washers. However, the spare parts list also shows that this modification started with VIN 012865 and did not end with VIN 012864 as SLS indicates.

Charles,
if you want to order the additional washers for good measure then you can see the part numbers for them in the picture. I'll also attach a PDF because of the size limit on photos.

[wwheeler]

Well that settles that. My only question is what EPC currently shows. Attached is the page for 230SL. What do you make of that? I don't even see the earlier version with the long bolt.

[Charles 230SL]

Alfred, thanks for clearing this up.  I've got chassis #003548 so I'll consider the Edition B picture as 'gospel'. I'll go ahead and order the additional washers in Edition C (chassis #012865 and later) for good measure. they'll likely come in handy when I align the trans/drivetrain.

I'll add these items to my order from MB:
Edition B
#38 = washer p/n 186 990 46 40
#40 = hexnut p/n 000936 012006
Edition C
#45 washer 136 224 03 66
#46 washer 136 224 05 66
#47 washer 127 990 04 40

Wallace, that SLS picture is somewhat confusing for someone with an early 230sl - it sent me down a rabbit trail searching for part numbers for those "threaded washers".  thanks again guys for all your help with this,, charles

[66andBlue]

Well that settles that. My only question is what EPC currently shows. Attached is the page for 230SL. What do you make of that? I don't even see the earlier version with the long bolt.

Wallace,
IMO the EPC is even worse than SLS. The picture you posted is from the 280SL spare parts list and does not apply to the 230SL. Now MB perhaps decided to just sell one kit for all models and that's why they chose that picture.
Also the bolt #29 in the EPC pic is #48 in the Edition C pic and is not the same as #29 in both Edition B and Edition C pictures.
The original #29 is a 111 part (p/n 111 240 05 71; I don't know its dimensions) that was replaced by #48 starting with VIN 012865 and its dimensions are: M12 x 30 mm DIN 933; really a short bolt!
Whether it was screwed in from the bottom instead of the top (like #29), as the picture might imply, is something that is beyond my shade tree mechanic knowledge.

[wwheeler]

It is confusing for sure....

[Charles 230SL]

The part number I have for the early 230SL through bolt (#29 in the Edition B picture) is 111-240-00-71 and I believe it's 80 mm. Alfred, does this part number match what you show for #29? (this is the bolt I'm about to order from MB).

[66andBlue]

Charles,
as I typed below in my response to Wallace, #29 = p/n 111 240 05 71, both in Edition B and C and used until VIN 012865.
Hope this helps.

[Charles 230SL]

got it,, thanks!