OverKill

I have a 2007 JKU with 150k and have to replace my front D30 axle it has 4.10 gears. I bought a used D30 with 3.73 gears with 110k. I am told I can reuse my gears. A guy on the forum has 4.10 with 23k on them for $250. I am told it would be cheaper and easier to replace gears with the axle off the jeep. I am not doing the work. I am trying to understand replacing the gears.
Questions
Do I need the carrier or can I reuse the carrier from the 3.73 and put in 4.10 gears?
Would it be better getting the gears with 23k instead of reusing my gears?
Is there anything I need to know?

nthinuf

Here is a good gearing how-to, it will give you a good idea of what is going on.

https://www.jk-forum.com/forums/jk-w...gearing-82262/

Talk to the specific shop doing the work. Some will not install used gears. Or may not warranty used gears. If they do, they will likely not install yours due to the seriously high mileage. But, let them take a look and see what they say.

Your current carrier is fine, it is only when you are swapping from 3.21's that the carrier is a problem. Also, if you have considered adding some form of traction, now is the time.

You might also see if you can find a take-off rubicon 44, and at least compare the price to whatever the shop is charging for the regear.

Elusive

1. is your front axle bent? if not I wouldn't change it.
2. it's a lot easier to swap the gears and carrier all at once. sometimes they pop right in and your done.
3. I wouldn't worry about the wear on the front gears. they rarely have any drive to them and don't wear much.