Bmw R100gs

[Mustang Boy]

Before you take the piss it's not mine!!!!!!

Anyone ever changed an alternator on one?????
Do i really need a grinder??

How the Fuck does it come out??

Cheers'en. :D

[johnr]

fooking wonderful things.
to pull the alternator, take off the engine front cover, the alternator is secured by 3 long bolts, just unplug the wires after marking which is which, and then take it off. leaving you the bit you want to take off, the generator rotor, take the allen bolt from the middle, the rotor is a taper fit on its shaft,and you will need to make an extractor pin to remove it. unscrew the allen bolt, it will come loose, but not out, you will need to pull it outwards, and then unscrew some nore, this will then allow it to come out.
to make the extractor pin, i use a 6mm bolt with the head cut off, leaving about 45mm of bolt. shove this 45mm bolt back into the hole where you took the allen key out, then put your allen head bolt back in and screw it down. eventually, the end of the bolt will come into contact with the 6mm bolts end, and will then start to exert a pulling force to release the rotor. if it doesnt come off easily, tighten it down till its good and tight, then strike the bolt head sharply and square on to the head, as though you were trying to knock it in. this invariably will free the rotor off.

though two things first beore you start. bmw's stop charging for a couple of reasons that dont need the rotor pulling. first, if the generator warning bulb has blown, the charging system wont allow the alternator to charge under 5000rpm, a new bulb will sort it. and if your bulb is ok, try cleaning the slip rings(the two copper bits on the end of the rotor ) with a bit of meths, if they get contaminated, they can stop the charge. also, check your alternator brushes arent knackered. they can and do wear right down, but as they are pretty much standard bosch car parts, any auto electical suppliers can sell you some, shouldnt cost you more than a tenner for the pair.