I have never done a gear install but I am pretty mechanically inclined, also my best friend is training to become a certified diesel mechanic. My question is I want to go from my 3.55 to 4.10, what is involved and do you think its something that my friend and I could do.
Blake
BTW my truck is a 4x2

 

It really isn't THAT hard... you just need to follow a bunch of diagrams and such, to make sure that you align the gears properly. Those gears have to be near perfect in alignment, you could do several things like:
1. Wear the gears outs prematurely.
2. Whining noises.
3. Totally destroy the gears.
4. Mess up the limited slip (if equipped).
And more...

Is it worth it to do it your self? Yes, and no. Yes, as in you learn how to fix a rear end pretty much. No, as in you could really cost yourself some money and possibly, but more than likely your time.

If you bring it to a good shop that pretty much has a guy who does diffs on a regular basis, then that is the person you need to see if you want to have it done right. But then again, that guy had to learn it too. So even though he might be good, I'm sure he causes himself some grief too... but he probably knows 101 ways to fix his costly mistake with ease.

One other thing you do need are some special tools. So beware of this. Of course, you also have to remember to add the posi fluid as well, that's if you have a limited slip diff.

But could a mechanically inclined person do it? Yes, with the right tools, a 12 pack of beer, and your diesel mechanic friend, then you shouldn't have a problem. However, make sure you check thrice before you seal the rear end up.

 

I would definitely take it to someone has has installed many, many gears. Experience counts quite a bit when doing gears to get the proper "SHIM". Transmission shops I believe have good experience with gears. Of course you can't speak for everyone. Not something I would do myself.