bearing sizes different on aftermarket sierra vs original equip manufacturer?

[robert_kelly]

IF the gear ratio is 21/17 . vs 21/21 .are there different size gear shafts then ?

 

[Droid]

I don't think so but I can't say for sure. That would cause all sorts of extra parts manufacturing, handling & assembly complexity. Not to mention replacement parts & service issues.

Tab over to the parts section & do some searching of your model & then others (including others years) & look for yourself.

I can tell you a press on bearing needs to have some type of physical stop (a shoulder of some sort) or it will move during use.