i have a 1997 sportsman 500 4x4. i tore up one of the rear drive shafts last year (broke the ujoint and broke off 1 of the yokes, i replaced the entire shaft and also had a front cv boot go bad. Anyway, fixed the front boot (helped a lot because that wheel would engage on its own and make steering a real [email protected]#) but now i have a new problem. The back of it jerks all over the place when i drive it. I jacked it up and this is what it is doing: the rear tire with the old drive shaft spins at a nice even speed, the tire with the shaft i replaced does about a 3/4 turn, stops for a sec then goes again (it is an even pattern of 3/4 spin, stop, 3/4 spin, ect). I have a clymer manual but it does seem like there is a differential lock for my machine. I know i'm missing something because this unridable. Thanks.