Rear Axle Upgrade

Hi! Pardon the dumb question...

Looking for some advice on upgrading my rear stock JK Rubi axle

I have a 2012 2 door Rubicon auto.

Stock 4:10 gears and stock locker.

Im going to be buying a PR44 Unl for the front (arb, 4:88, RCV, Reids, prosteers), and since Im doing that, would like to do the gearing, locker, and axleshaft upgrade in the rear at the same time.

Can I change the gear ratio, put 35 spline ARB, and 35 spline axleshafts in the same stock rear axle housing?

If not, are there any options where I can buy an axle housing and have it built for me like Im doing with the front PR? Ive heard a Trail rock 60 can be done, however, I want to keep the same 5 on 5 bolt pattern I currently run.

Thanks for your input.
 

olram30

Not That Kind of Engineer
I think we are stuck with 32 spline in the rear. Unless you had a sport or Sahara. I'm not real sure, something to do with the different length axles
 
Hi! Pardon the dumb question...

Looking for some advice on upgrading my rear stock JK Rubi axle

I have a 2012 2 door Rubicon auto.

Stock 4:10 gears and stock locker.

Im going to be buying a PR44 Unl for the front (arb, 4:88, RCV, Reids, prosteers), and since Im doing that, would like to do the gearing, locker, and axleshaft upgrade in the rear at the same time.

Can I change the gear ratio, put 35 spline ARB, and 35 spline axleshafts in the same stock rear axle housing?

If not, are there any options where I can buy an axle housing and have it built for me like Im doing with the front PR? Ive heard a Trail rock 60 can be done, however, I want to keep the same 5 on 5 bolt pattern I currently run.

Thanks for your input.

35 splines in the front too?
 
Yes. I would be using 35 spline in front. There is a lot of discussion and information about front axles but rear axle upgrade info is scarce

For the front, I hav to use a different housing if I want to do arbs. For the rear, would be nice to just buy axle shafts, gears and the arb without having to also buy a new rear housing.
 
Last edited:

Jaysend

New member
I've had a lot of shops and vendors steer me away from the 35 spline front.

I've also heard a lot of folks unhappy with 35 spline fronts. The shafts neck down and have the same outers so your not gaining much. Also lots of issues with leaking seals.
I think 32spline Rcvs would be fine up front. Out back, the 35 spline would be pretty slick.
 

wayoflife

Administrator
Staff member
Hi! Pardon the dumb question...

Looking for some advice on upgrading my rear stock JK Rubi axle

I have a 2012 2 door Rubicon auto.

Stock 4:10 gears and stock locker.

Im going to be buying a PR44 Unl for the front (arb, 4:88, RCV, Reids, prosteers), and since Im doing that, would like to do the gearing, locker, and axleshaft upgrade in the rear at the same time.

Can I change the gear ratio, put 35 spline ARB, and 35 spline axleshafts in the same stock rear axle housing?

If not, are there any options where I can buy an axle housing and have it built for me like Im doing with the front PR? Ive heard a Trail rock 60 can be done, however, I want to keep the same 5 on 5 bolt pattern I currently run.

Thanks for your input.

Honestly, I would save your money on the orange knuckles and use that money to get an HD tie-rod. Even with the additional inch of clearance, you're still gonna hit your tie-rod. Otherwise, your front axle setup sounds like a good setup.

Regarding the rear, you cannot run 35 spline in a factory Rubicon rear Dana 44. I personally would recommend that you run a Dynatrac Trail 60 and yes, you can get that at factory width and with a 5x5 bolt pattern.
 

wayoflife

Administrator
Staff member
I've had a lot of shops and vendors steer me away from the 35 spline front.

I've also heard a lot of folks unhappy with 35 spline fronts. The shafts neck down and have the same outers so your not gaining much. Also lots of issues with leaking seals.
I think 32spline Rcvs would be fine up front. Out back, the 35 spline would be pretty slick.

A lot of shops will try and steer you away from products they don't carry, don't make a lot of money on or on things they don't know how to setup right.

While I'm not a fan of RCV's if only because they aren't worth the extra $400 premium in my opinion, I have run a set them in 35 splines on a ProRock 44 and had zero problems with them. But hey, what would I know.
 

JKWrang

New member
A lot of shops will try and steer you away from products they don't carry, don't make a lot of money on or on things they don't know how to setup right.

This happened to me. Northridge4x4 steered me away from a rancho setup in favor of a TF 2.5" lift claiming that he (the sales rep) had seen a lot of failing parts from Rancho. Now, fortunately I still like the ride amd the Jeep and am very happy - but it pays to do your own research, hear the real life field stories and know what you want. Shops do this - I would too if I didn't make a profit on special order items like what I didnt carry.


Edit: im not bashing Northridge4x4 either - just offering anecdotal experience on that subject - im happy with my purchase and their customer rep did a great job finding me the best price and IMHO a good kit for my needs.
Sent from my SCH-I545 using WAYALIFE mobile app
 

Jaysend

New member
True, but the vendors I was referring to sell rcv and recommended the standard 32 spline Rcvs. A very reputable axle builder (mentioned many times in this thread) warned me about the seal issues with the 35 spline axles.

I was already leaning toward keeping the tru lok so I was easy to convince.

Just sharing what I've heard, I have no first hand experience with the 35 sine arb. I did see the 32 spline Rcvs next to the 35s though.
 
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