The drive chain on my 97 XLT let go last winter at topspeed and disintergrated my chain case. I'm replacing the case, cover, chain and gasket. The top sproket lost some teeth and obviously needs to be replaced. The sled has reverse so there are some additional sprokets in there. One of the smaller sprokets for reverse lost teeth as well. My question is do I need to replace every sproket in the case even if some look to be ok? How about the berrings and berring seals. I'm trying to keep it cheap, but I don't want any problems down the trail either.