‘95 K75 3A ABS Rear Rotor Assembly Screws

[72r60/7]

View attachment 87800

Augh !
Every time I run across these bolts I have shade tree nightmares. I have always replaced with new ones but have fits removing the old ones.

It’s like the Allen head is 5.5 mm an yet 5.5 mm is too large. They are just poorly made. (Too shallow and not even close to a 5mm hex shape) This from previous experience. Have been told to use a rubber band and jamb the hexhead in on top of that. I tried that in years gone by and can’t remember if it worked or not. Sure could use anther trick about now.

Last ones I tried to order I was told by Max that they didn’t even show up on the parts diagram an they musta been some sort of aftermarket part or added by a previous owner. HA ! (Kids and so sure of themselves)

Can anyone tell me where to find the part numbers.

Thanks folks.

Charlie

 

[20774]

Hmmm...I find this page and it suggests, if I'm reading it right, the fasteners are M8x20 TUFLOK. That doesn't tell us what the tool is used to get it out. According to some what I've seen online, I'm wondering if there's some blue Loctite on the threads. Maybe some heat would help loosen things up.

https://www.realoem.com/bmw/enUS/sh...93-K569-BMW-K_75_85_0562,0571_&diagId=34_1904

5.5mm ends up being something like 2.1 inches. 3/16" is 0.18xx inches. I wonder if that might fit better.

Here's your picture:

 

[98lee]

Charlie,

To remove those screws, use a 5mm bit in a manual impact driver. https://www.harborfreight.com/6-bit...MIh7P27qrT9wIV-AqtBh1BiQ6UEAQYAiABEgINYfD_BwE


Other methods of trying to remove these screws can lead to grief as the socket is only half depth and there is locktite on the threads. The socket can strip out very easily unless you use the above type wrench.

The part# for those screws is: 34 21 2 330 021 $4.02 They are still listed in Max’s parts fiche.


Sounds like you’re going through rear rotors way too often!

 

[pglaves]

Those are awful fasteners and the use of thread locker is a joke. Look at those pictures. All they do is keep the disk from falling off if the wheel is off. Otherwise the disk is tightly clamped between the wheel and the final drive hub. From original they have thread locker and some pin-point heat from a butane torch is helpful. From then on I use copper anti-seize on the threads which makes them easy to remove when necessary.

 

[69zeff65]

A little trick for those allen head bolts

I find the correct allen wrench socket and put a little water soluble valve grinding compound on the flats down at the end of the tool and then gentle tap it into the end of the allen bolts. You have to make sure you don't get any grinding compound on the tip of the allen socket.

 

[72r60/7]

‘95 Rotor screws

Many thanks for that part location, numbers and responses.

Good reminders why I didn’t ‘graduate at the top of my class’.

Not going thru rotors but with 3 different K75’s (kept ‘em all) since ‘92, there were seals, bearings and worn drive splines that warranted rotor removals.

I really enjoy the K75’s.

Charlie

 

[Danl]

I'm wondering if there's some blue Loctite on the threads. Maybe some heat would help loosen things up.

Here's your picture:
View attachment 87801

Must use heat!!! BMW uses the blue LocTite. I just had a final drive on a 87 K100RS in the shop and the PO sheared off one of the bolts doing it cold. If you take a little pinpoint torch to it at about 150f a small puff of smoke will appear. Then you can pull it. You can't animal these off, you have to talk nice to them.

I took the FD to my machine shop and they were able to use EDM to remove the broken bolt and save some space on my credit card.

When the new bolts came in I took acetone and removed the blue goo and used copper anti-seize like Paul suggested.