isn/t there a bearing at the end of the axle tube and how do you know if it needs replacement. I just got the 14bff off of an older truck, do you normally replace these bearings?? Do you just wait until they go bad? I am now thinking of going with the TSM rear disc kit thanks to everyone on this site, (always getting talked into things, I guess thats a good thing....isn't it?) Should I replace everything before I install it in the Blazer. I am going to be puting gears into it, anything else usually need replacement?