I have a 1999 Sportsman 335 and I noticed the rubber boot near the universal joint on the left rear drive shaft is twisted. When I squeeze or move the rubber boot I hear air coming out at the other end of the shaft near the universal joint close to the hub. There are no tears in the rubber boot but not sure why I hear air coming out from the other end of the axle. Here are some pictures of the rubber boot. Any help would be appreciated. Thanks.