Front driveshaft install question

[E30andy]

Hey Guys,

Me again....

Trying to get my front driveshaft back in. Having trouble with the 3 bolts that bolt into the output flange of the front diff. The bolts without the locking nuts.

They won't tighten for some reason. They get started, tighten up a little, then loosen right up again, liked they are stripped or something. What am I doing wrong?

Thanks!

Andy

[nando]

Unfortunately it sounds like they are stripped. What do the threads look like?

[E30andy]

I have to take it apart to check. The bolts look fine and they were tight when I took them out (if I remember correctly, it's been awhile).

If the threads are stipped can they be tapped and rethreaded?

[E30andy]

Wouldn't it be odd for all 3 of the holes to be stripped? Could the driveshaft be too deep in the transfer case and the bolts just aren't catching enough of the threads on the output flange?

[E30andy]

Looks like user error guys! Installed the centering pin wrong, duh!

Another question....

So, after looking at realoem, I dont seem to have the "ring cover", #15 in the diagram

https://www.realoem.com/bmw/enUS/sho...diagId=26_0040

How important is that part?

[nando]

it's just a bushing, I don't think it's super critical.

[E30andy]

Thanks Nando! You are a big help, appreciate the quick response!

[Nisse Järnet]

That bushing makes the drive shaft sit in center so i would highly recommend using one! You could get vibrations.

[nando]

I thought that was part of the front input flange - I thought there was sort of rubber "washer" that is pictured in the ETK.

[Nisse Järnet]

I could be wrong, but it really looks like the centering piece :)

[E30andy]

It was actually still there. Its just a flimsy piece of rubber, appears to be a bushing, doesnt look very important.

[nando]

yeah, I'm pretty sure there's a washer/bushing thing, and then there's the actual centering piece in the diff flange. I think that part is replaceable too, but they aren't the same thing. you could probably put any kind of rubber washer/o-ring in it's place and it would work just fine.

[Nisse Järnet]

So what does the rubber washer even do? :)

[nando]

Prevents metal on metal? I dont think its extremely important - you cant compress the shaft into the flange any further than the flex disc allows anyway.