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Bolt Length - Hub / Bearing Assy
scootz - 5/7/18 at 04:58 PM

Wee bit concerned.

I replaced a pair of front hub / bearing assy's this morning on a BMW.

First pic shows the bolt protrusion on the original hub.

Second pic shows the (lack of!) bolt protrusion on the new hub.

I've double-checked that I've ordered the correct assy's.

What do the masses say? Perfectly adequate... or would you want to see some visible bolt threads?





daviep - 5/7/18 at 05:48 PM

Depends......

If the new bolts are the same length as the old bolts and the lack of visible threads is due to the new hub having a thicker casting then I'd be happy as there will be more threads engaged.

On the other hand if the new bolts are shorter I wouldn't be happy as presumably there are now less threads engaged.

Cheers
Davie

scootz - 5/7/18 at 06:12 PM

Good point...

I didn't think to measure the casting depth.

Dingz - 5/7/18 at 07:32 PM

If all the bolt threads are engaged with the casting then thats fine. The spare bit of bolt protuding isn't doing anything apart from rusting.

scootz - 5/7/18 at 07:57 PM

quote:
Originally posted by Dingz
If all the bolt threads are engaged with the casting then thats fine. The spare bit of bolt protuding isn't doing anything apart from rusting.



It's difficult to tell. It looked like they were fully-engaged when I put it together, but my iPhone seems to have a better focus than my eyes do, and they suggest it's bloody close.

Different angle below.

nick205 - 6/7/18 at 08:45 AM

As daviep suggests I'd measure the length of the old and new bolts and the casing thickness first.

I also wonder is there meant to be a clearance for brake caliper/disk and might a protruding bolt on the later assembly foul this clearance?

Are both old and new parts BMW OEM or pattern?

Dingz - 6/7/18 at 10:52 PM

Looks fine to me.

Slimy38 - 7/7/18 at 04:22 PM

quote:
Originally posted by Dingz
If all the bolt threads are engaged with the casting then thats fine. The spare bit of bolt protuding isn't doing anything apart from rusting.


See, that's what I would have thought, but I'm fairly sure the IVA does check for a certain number of threads protruding? If it's relevant for that there must be a reason for protrusion (apart from turning a nice brown colour!)

scootz - 7/7/18 at 10:02 PM

quote:
Originally posted by nick205
Are both old and new parts BMW OEM or pattern?


Not sure if the old one was OE... I guess it probably was though going by the way it looked.

The new one's are aftermarket. Moog brand, so good quality, and I'd expect their kit to be right.