Rear disc rotor bolt head trashed

[Richard_Spag]

Hi guys,

 

Just removing a knackered rear disc and one of the five bolts that hold the disc to the rotor has become unservicable (not the word that I was going to use - but there may be ladies present!). There is no way that I can get anywhere near enough purchase using a T40 - so it appears that I may have to resort to a drill and stud extractor approach. The main problem is access to the bolt head - it would appear that I may have to remove the rotor onto which the disc bolts so that I can get it onto a bench to do the job properly. I see that there is a large external circlip on the hollow shaft adjacent to the rotor. My question is - will the removal of the circlip allow the rotor (to which the disc is bolted) to be withdrawn away from the final drive unit (without disturbing any seals or loosing the transmission oil?).

 

Many thanks (any other cunning plans also welcomed!!)

 

Richard

[Ken H.]

If you remove circlip 14, then heat soak the flange 13, it will slide off.

 

[Richard_Spag]

Many thanks for the exploded diagram -it confirms my suspicions! If you have to get the rear disc off at some point in the future watch out for these disc bolts - they take a heck of a lot of torque to loosen even after heat soaking!

 

Cheers

 

Richard

[JohnBeaven]

Just curious. How many miles to knacker a rear disc?

[Richard_Spag]

I was notified that it was on the wear limit at 24,000 miles (I am currently at 32,000). This equates to a new disc every year for me! The rear brake seems heavy on pads too (despite the caliper being free to move).

 

Cheers

 

Richard

[gdouglas]

I have had my rotors off for resurfacing one time and the BMW factory apparently uses the equivalent of red loctite on the rotor bolts. I keep a MAPP gas torch handy around the garage for mechanical assemblies that have difficult to loosen fasteners. I usually heat a suspected fastener for about 10-15 seconds and any locking compound is usually softened up enough to allow disassembly. MAPP gas is hotter than propane but not as hot as oxy/acetylene.

 

I feel for you on the one with a damaged head. If you are unsuccessful on removal with some more heat involved, you may have to drill out the fastner and do a helicoil repair.

[Fergie]

Take and weld a nut to the head of the trashed bolt on the inside of the nut. Then you can use a wrench or socket to get it out.

[s3steve]

Take and weld a nut to the head of the trashed bolt on the inside of the nut. Then you can use a wrench or socket to get it out.

 

+1 I had to do the same thing on my old GSXR1100.