alright i got a 12 bolt 410 posi rear and i plan on changing out my gears. a friend of mine was tellin me might run into probllems if i do it my self. how dificult is it to change out my gears ? what are the tourque specs do i need a micromiter or any other special tools

any suggegstions on gear oil?

Changing gears in a 12 bolt can be difficult if you've never done it before. Getting the shims/backlash correct is a must. Also crushing the crush collar properly, on the pinion is must. You will need a dial indicator to set backlash. It's not just a matter of torquing down bolts. Either get someone to assist you, who knows the process, or take it to a shop that does rears. If it's not done correctly, the gears won't make it through the test drive.

Just from the questions you are asking have it done by someone who can teach you and learn. Every thing above plus tooth contact paterns need to be done right or you get noisy mismatched gears that will break under load. Good luck!:thumbsup:

If you have a 4 series carrier the lowest (numerical) gear is 3.73.

Marcus

I didn't know that you could bolt up 3:73 on a 4 series carrier. I was under the impression that only a 4 something gear would fit.

I had my father in law teach me the process on my 10 bolt last summer. Definateley have someone help you or pay a shop. The worst part was tourquing that crush sleeve to get the ~10lb preload on the pinion.

THAT was a pain.

if you're dead set on doing it yourself then you should check out this page......
http://www.pirate4x4.com/articles/tech/billavista/Gear_Setup
....that should give you an idea of what you're in for.

I didn't know that you could bolt up 3:73 on a 4 series carrier. I was under the impression that only a 4 something gear would fit. After market makes thin 3.73 gear sets that fit 4 series carrier.

Marcus