Originally Posted by jur
I fixed an extreme creak recently in my MTB (by extreme I mean ppl 20 paces away were looking back
). After several vists the the LBS where they _claimed_ to have swapped the cranks and BB with no result, I bought a BB tool and opened it. Inside the BB there was a fine brown powder, like rust ground up, that looked mighty suspicious to me, so I cleaned out the BB by squirting in WD40 until it washed all the cr@p out. Then I reassembled the BB with grease everywhere, even between the cartridge bearing interfaces and the spindle and housing, put it back in and now the bike has been quiet for 2 weeks, the first time in months. I also greased the crank bolts, both the thread and the flange, as well as the square taper. (I did that before to try and cure it with no result.)
I fail to see why the bolts must not be greased? The changing of the torque argument, perhaps? Or self-loosening?
Sorry if I was not clear. It's OK (actually, it's recommended) to grease the bolts; it's the
taper that should be dry. The tapered spindle/crank relies on friction to remain secure and lubricating it defeats that, allowing the crank to cinch up too far on the spindle. If the crank bottoms out on the spindle it will work loose, ruining it.