Strange bolt beneath the gearbox;

Bruce Frey · Post by **Bruce Frey** » Thu May 22, 2008 11:38 am

AH....there it is. 251 1 72 003 00 for the R51-R71.

The frame diagram for the R51-R71 on Lacko's site is spread over 2 pages. It was illustrated on the front page rather than the rear page where I was looking for it.

With no bike handy to look at, it seems that the orientation of the spring would be more side to side than front to back, is that correct?

I love it when I learn something new about these bikes!

Ciao,

Bruce

EuroIron · Post by **EuroIron** » Thu May 22, 2008 3:14 pm

Micha

you can remove that and reinstall with no problem

takes only a minor bit of finger diddling to get it back in

let me know if you'd like to see pix

I have a couple open

Micha · Post by **Micha** » Thu May 22, 2008 11:47 pm

Thanks, I will be glad to watch those pics (michasteinmann@gmail.com).
It is possible that this part is remains from the dinosaur's time

, just like the right hand lever of the gear change mechanism, and has no function today. Interesting is, why does BMW not cancel those from-the-past parts?

saintclair2703 · Post by **saintclair2703** » Fri May 23, 2008 3:57 pm

Well, the plug I was talking about is the drain plug that was replaced with a "compression plug" that is totally bogus. I hope to God I don't have to take out the whole transmission to reove it. So far- it won't come out...

The plug you're talking about has been described as some kind of retainer for a spring. EuroIron says there's no problem with taking it out -in order to put some sealer in there to prevent it from leaking? Vechorik says told me not to use it as a drain plug because the devils of hades will fly out and eat my face.
Might be an improvement for me, but i don't know about the bike.
Anyway, let us (me) know how THAT little project goes.

Any advice on how to get a compression plug out?

schrader7032 · Post by **schrader7032** » Fri May 23, 2008 4:43 pm

Any advice on how to get a compression plug out?

Have you seen one of these things in the autoparts stores? I mentioned it's a section of rubber capped either side by some metal plates. The nut on the outside just squeezes the two plates together, forcing the rubber to expand outwards, creating a seal.

If it's one of those things, you should just loosen the exposed nut, maybe about 5-8mm so that the threaded rod is exposed. Then grabbing the nut or rod carefully start working the rod back and forth attempting to break the rubber seal with the ID of the engine case hole. It may require some downward force to get it to walk out the hole. If there was a way to apply some shock force to help pull it out of the hole, that would be good. You might try some penetrant liquids to work between the rubber and the engine case to help things slide a bit.

Kurt in S.A.

saintclair2703 · Post by **saintclair2703** » Fri May 23, 2008 5:04 pm

Haven't tried the "walking" part yet. Good idea. I have a feeling there's a good portion of thread left in there, and so far tugging / twisting has not accomplished anything.

It just occured to me to try working a very small screwdriver around the edge... I'm glad we had this little chat! (I think I may have to take off a pipe to get the cross-pipe out of the way.)

schrader7032 · Post by **schrader7032** » Fri May 23, 2008 5:22 pm

Do you expect the hole in the case to be threaded? I'd be careful with working a screwdriver along the edge...

Kurt in S.A.

VBMWMO · Post by **VBMWMO** » Mon Feb 15, 2010 2:52 pm

Hello Friends,

I have this strange bolt/plug sticking outside of my gearbox, just near the gearbox drain plug (I marked it with an arrow). It is leaking oil and I would like to know what it is and if it is not a big deal to make it stop leaking. According to the parts list, it could be Nr. 1056241 but that is defined as a "cover" (?).
The big bolt near it is the oil drain plug, not original, of course.
Thanks a lot for any explanation, Micha.