What is this bolt that just fell from my w123?
 

https://i.imgur.com/TW2eBfUl.jpg

https://i.imgur.com/BqYo7qYl.jpg

https://i.imgur.com/ueORuBal.jpg

Backed out my two w123 cars today and found this. Hadn’t done any jobs on either in a while.

Not a familiar bolt, the thick washer is curious.

Totally speculative that it fell out of something versus had been someplace where it fell during a parts replacement long ago, and just jiggled out.

Does this look familiar to anyone for anything???

It looks like the bolts that hold in the transmission mount support bracket, or the mount to the bracket.
https://lh3.googleusercontent.com/o0...M=w800-h453-no

With that thick washer, I'd be checking the alternator or other accessory brackets...

Possibly harmonic balancer?

Yeah, I agree it looks like an accessory bracket of some sort given the washer thickness.

The transmission mount and bracket use thick washers like that. That's what tipped-me off to it being a possibility.

I agree. If it uses a 17mm tool, then definitely.

17mm for the bracket itself. The bolt I found was 13mm.

I think the bolts for the transmission mount themselves are 13mm, but they’re both there.

https://i.imgur.com/cEaDmGnl.jpg


But I think I found it on the t-stop mount.

https://i.imgur.com/oG6woKrl.jpg

Haven’t installed it yet to verify.

I torqued it to spec... strange for it to back out.

Yes spot on and a good find .Nothing like dropping the bolt down the engine as your working on it .

Lol btdt too many times. I’m just glad this one rattled off in the driveway vs on the rod where it would be lost.