I am rebuilding a W115 1971 220D.
Car body is 1971 and used to be a 220 gas. The engine is in fact a 1973 220D
OM615.912 Block # 6150111301 arrow at B 26A 73. See fig. 1


fig. 1


I will try to create a thread with all pics and info some day. Here is what is going on currently:

The intermediate gear shaft for the injection pump and timer device has a lot of play. Reading throughout the internet, everyone says to replace the front brass bushing. Apparently vacuum pumps have been destroyed in other scenarios.

Mine appears to have play in the back bushing and front bushing.
6150520150 - rear bushing for intermediate shaft.

6170520106 - front bushing for intermediate shaft version 3
6150520106 - front bushing for intermediate shaft version 2
6210520106 - front bushing for intermediate shaft version 1

I already pressed the rear bushing out and will be ordering a replacement.
I am not convinced however that just replacing the front brass bushing will do as there is some wear in the actual bushing that is in the block (probably from all the movement it wore out). That bushing is supposedly non replaceable. It does however appear to me that it is pretty much the same bushing as the rear one except for the two oil holes.Has anyone noticed wear on that part before and better yet, has anyone replaced one of those before?


Notice the grooves in the block - I've looked at a few other pictures on the internet and they didn't have such grooves - appears like the chain was dragging. In the middle you see the bushing I believe needs to be replaced.



Here is another picture from a different angle and you can see the wear grooves in the actual bushing. when I run my finger trough, it seems pretty bad.


This is from the back (injection pump opening), and here you just see the cast iron and not the edge of the bushing. If it was the edge of the bushing, it would be pretty easy to push out.



So would a 6150520150 work to replace that bushing as well (granted I drill the two oil holes in it of course) ??

Hey Tedd, did you ever figure this out? You might post this to Diesel Discussion too, to get more eyes on it.

I dug around in my FSM for 615, 616, and non-turbo 617 engines and found section 05-412 "Removal and installation of intermediate gear shaft". This section covers the different versions and shows detailed drawings of the assemblies as well as the front and rear bushings themselves.

There is only one removable bushing for the front of the shaft. Once the front bushing that's held in by the bolt/washer is removed there is nothing left to remove/replace.

It looks to me like the front bushing spun in the bore, thus wearing the grooves you can see/feel. Maybe the lock washer and bolt fell out and allowed the bushing to spin with the shaft? It also appears to me that what you are seeing as a bushing is in fact a pattern worn into that surface by the spinning front bushing's front flange. This is why you cannot see the "bushing" from the rear.

Seems like time to talk to a good machinist about making a repair to that bore to restore its ability to hold the front bushing in place. Sleeve? Weld in new material and align-bore it? Maybe just find another block?

Be happy to hook you up with some high-res photos of the FSM pages in question, if you need 'em.

__________________
- Greg -
1973 220D, The Prodigal Benz
1974 240D

Should have followed up sooner on this,
I ended up replacing the rear bushing with a new one (this is pressed in) and also the front brass bushing (this is the one held by the bolt and washer). Most of the wear turned out to be in the front brass bushing.
Once the new parts were in, I was completely satisfied with the amount of play - it was minimal.

I don't think the bolt and washer actually fell (those were where they are supposed to be upon dis assembly) - the brass bushing didn't spin out but rather as it wore, it dug the grooves into the block. The old bushing felt very loose. The new bushing almost had to be hammered in so it fit great.

I have been using the FSM through out this build. By the way, I did get the engine to run prior to dis assembly and it didn't sound too bad - had been parked for 10 years and Injection pump control rack was stuck, once freed up, it started and idled just fine.

Bottom line:
1x 6150520150
1x 6210520106 (this matched the one that was in there)
fixed the play.

The engine now has about 800 miles on it and seems to be doing good. I will have to post more stuff once I have time. All suspension (front and back) has been rebuilt, now dealing with paint.

Here is a pic of the engine going in:


Here is a pic of my made up tool to spin the oil pump with a drill in order to prime it before starting (This was a great idea and I highly recommend doing this so you don't turn over the engine dry):