Bike is a new to me 06 CRF450 I went to rebuild the shock and the preload locking nut came off perfectly and the threads above and below the main nut were immaculate. However i couldn't get the main nut to budge first with a punch then with a spanner wrench I fabricated. I soaked it in penetrating oil nothing. I ended up modifying a 2 foot wrench and with difficulty I removed the nut. The threads were stripped out where the nut was and I fought it all the way down. Now I'm looking at buying a shock! The only thing I can think of that would cause this is the jam nut being loose and it being ridden that way? Any Ideas? Is it possible I missed something? I can't find anything in the manual and I watched a video and it seemed easy.