removing retaining screw for discs

Post Thu Mar 28, 2013 10:30 pm

hi any tips for getting these off as in the past the head has sheared and ended up drilling old screw out. will wd it before hand any tips welcome thanks

Post Thu Mar 28, 2013 11:01 pm

Ensure that you use a screwdriver that fits snugly in the crosshead - tap it in with a hammer if possible, to ensure it's fully in.

Some heat with a blowlamp beforehand will help loosen it.

Post Thu Mar 28, 2013 11:38 pm

OE screw is female hex., so a cross head screwdriver isn't ideal! IIRC, it's BMC stuff that uses a cross head screw.
Same principles apply though - use a good quality male hex driver, clean the socket out carefully, and make sure it's fully home.
Always fit the screw with a good helping of copper grease, and don't over tighten it. This won't help you this time, but it will the next.
If the socket has rounded off and it refuses to budge, just turn the disc until the screw is opposite the calliper, remove the calliper and bracket, and give the disc a good smack from behind, through the space where the calliper fits, with a large hammer. This will shear the head clean off of the securing screw, and then you can grip the remains with mole grips or similar to unscrew it from the hub flange. The smack with the hammer will NOT damage your wheel bearings, the disc, or anything else as long as you hit it hard enough. If you're worried about damaging the disc surface, place a bit of sheet steel over the part of the disc that you hit.

Post Thu Mar 28, 2013 11:46 pm

Thanks will try that if i can not unscrew will update hoping to do this good friday if its not to cold ....

Post Fri Mar 29, 2013 12:06 pm

Brianmoooore wrote:OE screw is female hex., so a cross head screwdriver isn't ideal! IIRC, it's BMC stuff that uses a cross head screw.

My bad.

I forgot that a modern-fangled thing like an E30 would probably use a Hex or Torx bolt. You're right, BMC cars use a large cross-head bolt.

Post Fri Mar 29, 2013 7:16 pm

sorted . wd 40 last night looked rusty . put 5mm hex key in bit of tapping with hammer and came off easy , must have used copper slip in the past thanks for advice.

Post Sat Mar 30, 2013 1:00 pm

Brianmoooore wrote:OE screw is female hex., so a cross head screwdriver isn't ideal! IIRC, it's BMC stuff that uses a cross head screw.
Same principles apply though - use a good quality male hex driver, clean the socket out carefully, and make sure it's fully home.
Always fit the screw with a good helping of copper grease, and don't over tighten it. This won't help you this time, but it will the next.
If the socket has rounded off and it refuses to budge, just turn the disc until the screw is opposite the calliper, remove the calliper and bracket, and give the disc a good smack from behind, through the space where the calliper fits, with a large hammer. This will shear the head clean off of the securing screw, and then you can grip the remains with mole grips or similar to unscrew it from the hub flange. The smack with the hammer will NOT damage your wheel bearings, the disc, or anything else as long as you hit it hard enough. If you're worried about damaging the disc surface, place a bit of sheet steel over the part of the disc that you hit.

If stubborn and needs a few smacks you can damage the bearing, happened me with a spare strut I wanted the backing plate of. Bearing must have been shot but it defo came apart before the securing screw sheared.

Post Sat Mar 30, 2013 1:29 pm

Jozi wrote: If stubborn and needs a few smacks you can damage the bearing, happened me with a spare strut I wanted the backing plate of. Bearing must have been shot but it defo came apart before the securing screw sheared.

That's what happens if you don't smack it hard enough! Swing the hammer and knock it off in one, and no damage will occur.