ez53436

Was replacing my alternator voltage regulator and went to install the alternator in reverse order. There are two bolts that hold the alternator to the engine block. I put the upper one in its slot to keep the alternator aligned but didn't tighten it at all. I made sure the alternator had plenty of room to jiggle. So as I screwed in the bottom bolt, I kept lightly jiggling the alternator to make sure I was following the path of least resistance through the bolt hole (to make sure I wasn't cross threading). Long story short, the bolt became very hard to turn toward the end and I figured I should back it out to make sure I'm not stripping it. It was very difficult to back it out and I kept trying to move the alternator around to make sure there wasn't any crazy pressure being put on the bolt. As I back the bolt out, the piece that the bolt threads into breaks off. Like it's sitting on the belly pan. As far as I can tell, it's a nonremovable part of the engine block.

I know this is insane--but any ideas of how I or a shop could repair this? I assume something custom will have to be fabricated.





Broken part where lower alternator bolt screws in


Piece that broke off engine block

tjts1

That's not the engine block. That's a bracket that holds the alternator to the block. Replace the bracket. Don't try to gorilla it next time.

ez53436

You're right. Did some more research and found it's the timing case cover. It's a $700 part (1120100833) and from the WIS, looks like an enormous, labor intensive job to replace. I expect a reputable shop in the SF Bay Area to charge me upwards of $2k for this. That's why I'm trying to look into possible custom options--like any possibility of creating some sort of custom bracket behind or in place of the broken part. I would expect this to cost a lot less.

And I repeat--I didn't "gorilla" it. I've done plenty of work on my cars over the years and have never had an issue like this. I'm always extremely careful. The only idea I have is that the sleeve/spacer in the lower bracket was not seating properly into the bracket. It was going in crooked. That could be what caused the bolt to follow that crooked path.

PJmak

Do it right, forget the custom idea trust me.

Would you buy a car from someone with that kind of custom work done?

Id get this part used. There are plenty of salvage yards out there with blown motors that'll part them out. Heck I think I even saw one on the forum here somewhere. Its a M112 part so itll work from any m112 or m113 motor and there are plenty of those.

You can probably get that part used for less than a hundred. I recently the away a m113 block with all that crap on it.



Take it to a good shop and have the timing chain done while at it but honestly you can probably do this kind of job your self.

PJmak

This page shows some pictures on what youd have to do.

https://mbworld.org/forums/w211-amg/...ock-awe-2.html

feets

You're done with that part. It has to come out.

For what it's worth, it is the same on all 112k and 113k engines.

You can try to tig weld that thing back into place but it can be tough to weld a casting like that, especially considering the environment it has lived in.

Things like this are one more reason I enjoy having a machine shop at home.

PJmak

https://mbworld.org/forums/market/703709

ez53436

Thanks for all the input. Still deciding what to do with this and thinking that I may be able to reattach the piece that broke off by welding it back on (or possibly JB weld). This material is obviously not steel, as it isn't magnetic. Does anyone know for sure what it is? My guess is aluminum but I'm not sure at all.