Don't bother replacing the boot. Those kits you buy are a joke. I have been riding on my axles all Summer and this Winter and had way more axle grease slung out (I am waiting for Spring). I would just replace the both axles and call it a day because I can bet if you replace just one the other boot will rip too. Look at Rockauto.com they are pretty cheap and worth it. While you are in there take a look at your motor and trans mounts also.