Gear HELP!! pinion problems..
 

so yesterday i switched from 4.10 to 3.73. was not to happy with the 4.10. anyways not the point. when i did the switch i ran into so trouble the pinion is now loose. and i can not tighten the bolt any tighter it wont let me and yet it still moves. and then i though maybe if i got the guts in maybe it would get tighter and it did a little but it still moves in and out some. and i know there should be no play in this it needs to be tight. but i had to have my car for work today so i finished it up and filled it with oil so i could get to work i just drove carefully. and i got to work and noticed it is leaking from the pinion. which i now it was probably going to since it was not very tight. so heres the question. what i wrong? why is it not getting tight? and how do i fix this problem?

did you put a new crush sleeve in?

yes i did put the new crush sleeve in.

Has to be a shim issue then.