I'm currently running my 2008 Unlimited Rubicon on a 2.5" Teraflex lift with 33's and PSC fenders. I've wheeled most all the hard trails SoCal has to offer and even the Rubicon. Doing the Dusy Ershim trail in August. Jeep is 90% daily driver (50 miles on freeway daily) and 10% rock crawler. I'm planning to upgrade to either 35's or 37's and want to make it bullet proof.

35 build list:
prorock 44
swap over axle internals
regear
315/70r17 duratracs
Omix Ada unit bearings

37 build list:
prorock 44
RCV 35 spline CV axles
regear
37/12.5r17 Kevlar MT/R
Omix Ada unit bearings

Thoughts? Am I missing anything? Will I fit 37's with my 2.5" lift and PSC fenders? Am I asking for trouble by doing 37's and risk breaking things?

 

what 33s do you have now and how wide are your wheels? you may or may not even see a size difference with the 315/70r17 duratracs, as the true size is listed 34.4 and, can be as low as 33.5.

Also, from a technical standpoint, is there a reason to not go with the axle upgrade to RCVs regardless of the tire size? ( other than $$)

 

Why not keep the rubi housing and add a truss or sleeves and gussets? Unless your housing is already bent or broken I don't see the point of going from a 44 to a 44. If you daily driver this thing 50 miles a day I would suggest you stay with 35's or under.

 

I am looking at 37's too, so I have been looking at a lot of threads about axles and shafts. There is a thread on WOL about the RCVs twisting and not being covered on warranty. There are other posts about the difficulty of replacing them in comparison to a u-joint style axle. The cost is pretty high compared to Chromoloy axles with U-joints.

I'd go straight to 37's so you don't have to pay twice for gearing.

Also look at hydraulic assist for the steering.

 

RCV's have a no questions asked warranty for breakage, I've never heard of an original owner being denied a warranty claim. What exactly do you mean by twisting? Got a link to this thread?

 

Shouldn't you be looking beyond D44's?

 

I'm currently running Duratrac 33's, so going to Duratrac 35's should gain me an inch or so. I've been extremely pleased with my Durtracs.

I've read RCV axles are a "break it, we replace it, no questions asked" policy. I thought about chromoly axles, but the weak point is the u-joints, so I feel RCV axles would be more bullet proof.

I thought about keeping the stock housing and doing sleeves, gussets, etc., but a truss requires a bigger lift kit to fit, I read that with sleeves you can't run the 35 spline axles, and going with the buy it once mindset, it's probably better to simply go with a prorock axle.

I should be able to go with either 5.13 or 5.38 gears (still need to research more) and those will work with both 35's or 37's. One option is to build for 35's now and then swap in the RCV axles and 37's after the 35's wear down (2 step upgrade).

 

If the PR44 is in the budget, it will be an easy swap, and work with both tire sizes. Dynatrac makes a housing that will accept both the factory Rubi locker, or an ARB air locker, if you ever want to go that route.

 

I have nitro sleeves and can run 35 splines. I also have a purejeep truss with 2.5" of lift. You wouldn't have a problem either way.

 

excellent info. thanks.