I've decided to rebuild my non-rubicon D44 rear end. I'm a bit confused on this point: I know the rubicon has a 32 spline axle shaft, while the non-rubi has a 30 spline axle shaft.
I was planning to install an arb locker, new gears, and axle shafts. It's been recommended that I go w/ 30 spline chromoly shafts rather than the 35 spline shafts due to the abundance of 30 spline shafts on the trail. That makes sense, but wouldn't 35 spline axles be stronger? Why no 32 spline lockers from ARB?

 

A 35 spline would be stronger, but I've only seen 1 company who makes them for a D44. So strength vs. availability doesn't even out the cost. Especially with all the JKs running 37's+ & locked on a 30 spline with no problems. I believe in the FAQ even says upgrading to a chromoly in the rear is not really needed. So spend that $500 on a locker up front or somewhere else...

SemperFi

 

I forgot about reading the FAQ's. It would indicate that chromoly shafts for the rear are not needed. That would save a chunk of change to spend elsewhere.

 

http://www.quadratec.com/products/16120_45XX_PG.htm

Do you really think you will need to worry about snapping those shafts and needing to borrow one on the trail?

 

Hard to say if I should worry or not. You probably have a better idea about this than me so I would defer to your advice. My first thought was going to the 35 spline axles. I would like to save the money for the shafts if I can, but I will spend it if it is needed.

 

good conversation with a local shop that put the axle spline count into perspective:

30 spline chromoly shaft weaker than the ARB locker, shaft breaks first.
35 spline chromoly shaft stronger than ARB locker, locker breaks first.

advantage for me: easier to replace a shaft than a locker plus I will have a 30 spline shaft after the rebuild for replacement if shaft is broken on the trail.

 

Yep. I am a fan of the 'axle as the weak link' philosophy also. But I don't think you would need to worry all that much about breaking an arb. Maybe getting stupid with a bigger engine and 40+ inch tires?

That said, I went with 30sp shafts for my arb as well. Plenty stout for my use.

hxxp://www.youtube.com/watch?v=PHvk2YuT7hE&feature=channel

 

We're seeing a bunch of rear gear failures in JK44s with aftermarket gears. It's more common with large tires but the aftermarket gears are weaker than the 4340 shafts or the ARB.

 

I believe that I read that most after market gears are made by the same vendor, and just re=packaged. Is this true? Is any one brand better than another?

 

Very true. The only other option is very new. U.S. Gear has just released 4.88s for a the front and rear JK 44s. They are made of 4320 steel instead of the normal 8620. It is much more durable and the processes are much more consistant than your usual overseas gear vendor. They are more expensive than the the current gears but, despite their cost, they would be my only choice if I wanted 4.88s.

Unlike some gears that have U.S. in the name, U.S. Gears are made in the U.S.