Removing the hub from the rotor?

[Lars]

Ok, what is the easiest tool to use to get the bolts out of there? I tried a simple allen wrench and needless to say, it didn't work. What size are those bolt (hex)? I'm thinking about getting a hex bit for my socket set so I can use my impact wrench, or would that be a bad idea?

[BillWilliams]

You can hold the hub nicely by putting the studs in an old wheel, this keeps things from spinning, also work as you torque it tight

[jonny]

That's a great idea. Don't recall the size, but put the allen socket on a HAND/hammer impact and give 'em a good whack! If they still don't move...put a Mapp torch on 'em for a few minutes...then try again.

If you strip the inside of the allen head, go to the next size up (metris) whack it in there and try again.

good luck!

[Lars]

Problem solved, thanks.

[Guest Anonymous]

A few tips regarding rotor removal:

The factory manual shows the use of the road wheel to hold the assembly still - just as Bill W states. Works every time, and makes you feel "old school".

I wouldn't use impact tools of any kind (air or otherwise) instead - make sure the allen heads are CLEAN and use the correct Metric hex bit in a ratchet or breaker bar (I *think* it's an 8mm head - either that or 10mm)

If they are already mangled beyond repair - a TORX bit will sometimes come in handy to remove them - but must be tapped in FIRMLY with a hammer....it's a slippery slope from there on.

bottom line - use the right tools and finesse - way faster than sharp blows and breakage. They'll be tight - the use of heat is a great suggestion, too!

Keep in mind that the correct bolts are (at last I researched anyway) No Longer Available - and they're surely hardened bolts (probably 10.9 or so - not standard 8.8 grade) Try finding THOSE at Home Depot! *sigh*

Also - use new split lock washers (one of the only places BMW uses split lock washers instead of wave washers - 'cause wave washers won't FIT in there).

Use correct factory torque specifications and BLUE Loctite when reassembling. Too tight can cause warpage during use.

If you do both wheels at the same time and plan on re-using the wheel bearings - don't mix up left and right ones! It blows their Mojo.

Paul Wegweiser

[jonny]

A few tips regarding rotor removal:

I wouldn't use impact tools of any kind (air or otherwise) instead - make sure the allen heads are CLEAN and use the correct Metric hex bit in a ratchet or breaker bar (I *think* it's an 8mm head - either that or 10mm)

Paul, with all due respect I absolutly disagree with you.

I've been wrenching for 35+ years and EVERY nut/bolt that has ever **snapped** was done with a breaker bar at a slow turn.

Now when in doubt, I always use a little heat 1st, then a **whack** with a hand impact OR a **whack** without any turning pressure.

My results have been probably 99% removal of difficult or potentialy difficult fasteners.

1% = those partiularly stubborn ones that under no circumstances have the abilty to be removed as a complete item.

When it comes to exhaust studs/nuts on old M10's, I will cut the nut off before I even think about putting a wrench on it if the object looks prone to **SNAPPING**.

[BillWilliams]

from MAX two weeks ago.

Eric Kerman gave me the formula for loosening rusty bolts.

Penetrant, heat, a whack then turn or loosen with impact