Upgrading to UD44 front 18 JLUS

jerrygcoffey

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I have a 2018 JLUS with d30/d44 lsd. I am looking to upgrade the front axle to a UD44, which includes lockers and gears. I’m running 35s and want to go up to 37s eventually. My questions are, what gear ratio should I choose? Do I need to re gear the rear as well? Should I throw a locker on the rear as well? I’m having the rotational knock problem that’s common with the LSD and I’ve heard one solution is to put a locker in place of the LSD. Just looking for advice on how to do this build.
 

MarkY3130

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You will need to have matching gears front and back.

A locker in the rear is used more than one in front.

I have a manual trans with 4.88 gears. I wish I would have gone 5.13’s. With the auto I think 4.88’s would be perfect for 37’s.
 
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jerrygcoffey

jerrygcoffey

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You will need to have matching gears front and back.

A locker in the rear is used more than one in front.

I have a manual trans with 4.88 gears. I wish I would have gone 5.13’s. With the auto I think 4.88’s would be perfect for 37’s.
Could I run the 4.88s with 35s until I upgrade to the 37s?
 

scrape

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I would do a 4.10 UD44 and then buy a rubi rear axle. They go for ~2k brand new. You will make that back by selling both of your stock axles. Keeping your stock rear axle and upgrading it increases your net cost significantly. Axles are also something you can install yourself with basic hand tools, which saves on labor. Re-gearing and locker installs are generally not DIY for most people.

This is assuming you have an automatic. If you have a manual, I agree with Mark.
 

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