I have a 2007 JK with 3:21 gears and manual trans.. Have access to 2010 JKU (auto) front and rear axle assemblies with 3:73 gears. Wouldn't cost me anything more than my time to swap them out.

Obvious advantages are:
Newer hardware with less wear and tear
No need for new front carrier when upgrading gears in the future

Looking for thoughts, comments or downsides I haven't considered.

 

Its the same axle assembly for both years. The gears are the difference and if the axles have an electrical wire protruding from the top then they also have lockers. Either way they are a direct interchange.

Some of the x/sport models were ordered with lockers. Rubis come standard with them.

I dont believe u can get lockers in a sahara at all.

Good luck.

 

The swap is easy and way cheaper than re-gearing from 3.21 to 3.73.

Saharas may have a LSD in the rear, which was an option. If so, there will be a tag on the rear diff near your cover (or a tag that says LSD fluid required).


Go ahead a do it!

 

Oh, 3.73 gears means you won't have the rubicon axles, which would require different drive line connectsion at the T-case.

Everything should be bolt in for you!

 

Ultimately, when the funds are available I plan to re-gear. Until then the 3.73s will help a bit and save me from needing a new carrier on down the road. During the swap I'll do the brakes, change fluid, inspect the inside of the housings and replace diff cover gaskets.

 

If you were going to re-gear later, I'd save up and get a rear selectable locker at the same time. However this approach will entirely replace your carrier in the back.