Atmos

so that would be the same as 4.56 for me. I see that plenty on here though I would be comfortable doing that
but I'd rather go deeper if I can. I only get to do this once remember

also, I can drop a lunch box in an xj 44 without removing R/P right?
what about a full carrier without removing rp

BrofessorXJ

Currently running an open 3.55 d30 and an open 27 spline 8.25 on 35's and so far so good but don't wheel it too hard since it is still a dd. Plan on swapping to an 8.25 29 spline with lsd shortly. From what i've heard you'll be okay on the d30 with truss and upgraded shafts. My buddy does some pretty heavy rock crawling on his d30 on stock gears with 35's and has yet to break something.

Atmos

I like your rig man. the 35's just look so much more vicious than the 33's.
but no I stated before that I have pretty much no plans to get chromo shafts
I want to target my shafts as my weak point. and I dont think a truss will help me from stopping breaking a shaft will it?
seems a little overkill. I think I'll do a poll and see what people would do

BrofessorXJ

Thanks man really appreciate it.
I would think you would want to keep your axle tube as straight as possible any flex or bend in your axle could lead to strain and a break in a shaft a lot easier. However, I am not a D30 guru. My plans are to keep wheeling it, see what holds me back and breaks, and upgrade it from there.

Atmos

yeah I'll subscribe to that axle swap for sure
well thanks for the input I'll talk to the guy whos gonna do my gears and LA's for me about fabbing a truss as well

outlawtr450

also consider that if your goin 4.88's from im guessing 3.73's ur gonna have 2 change carrier's, i plan 2 run 4.88's with 35's but im mostlikly gonna run cromo's with cv's

BrofessorXJ

What long arms are you going with?

I know it's far but I've got a good buddy down here in LA that is going to be doing all my armor fab, bumpers and racks, axle, and gear work since I cant weld... yet. He's really good. We also installed my lift at his shop which made it 10x faster and easier with a lift and air tools than on the ground. If anything take the trip down we have a handful of big XJ's that wheel regularly if you're ever in the area.

xjmarc

I ran 4.56s and an Aussie with stock shafts and MTZs on mine without issue and I beat the crap out of it. Rear axle was another story.

Atmos

what did you have in the rear? I was gonna keep it open until I can afford a lunchbox

can anyone help me with the grimmjeeper calculator?
I dont really understand metric, but I entered::

AW4 auto 231. looking at the 35 km2's

3.55 at 215/75/R15 (27.7inch)
gear 1: 10mph @ 1206rpm
gear 4: 65mph @ 2099rpm

4.56 at 355/75/R15 (35.96inch) (DO I NEED TO CHANGE THE 75??)
gear 1: 10mph @ 1193rpm
gear 4: 65mph @ 2077rpm

that seems like a hardly noticeable difference. if the 75 doesnt change anything I think I'm fine at 4.56

4.88 at 355/75/R15 (35.96inch)
gear 1: 10mph @ 1277rpm
gear 4: 65mph @ 2223rpm

the main question is, what will my fuel economy look like for dd with 4.56 vs 4.88. unnoticeable difference?

Monster Mopar

Running 35s in my HP30, w/ 4.56 gears, ARB, chromos with the larger spicer 760 u-joints in the axle shafts. First thing that broke was the R&P.

I stripped out about 12 teeth off the ring gear (Yukon gears). But I was in reverse when it happened, and when driving on the coast side of the gear it's something like 20% weaker (so I've read). Makes sense though when you consider the shape of the gear.

If this is also your DD and you don't plan to go bigger I'd go with the 4.56 gears. I can cruise 70+ on the highway and still get 16+mpg, that's loaded with cargo and climbing mountain passes, and still have power for the trails

Atmos

yeah like I said. no chromo for me. I'll replace shafts all day before I do RP again.
ok I can live with that thanks. but I wont have a roof rack or spare or any armor except sliders for awhile
so fully loaded for me is they weight of the tires pretty much hahah

but does anyone know what the 75 means in 215/75/R15??
what would a 35x12.50xR15 be in metric?

Zoid365

I know just what your going through. I have wheeled for years with open front diff and 33s. This past winter I switched to 35s with an 8.8 in the back, and Spartan locker up front. And 35 MTZ's It really changes the way you wheel. No More throttle through whatever your going through. But the ability to crawl is AMAZING! I wouldn't trade it for anything! one of my favorite upgrades I've done yet. I went with 4.56 gears for 2 reasons. 1st cause the difference is so small from that to the 4.88s. 2nd the stroker has the torque to make up the difference of the shorter gear. I did Blow apart my long shaft on the D30 1st time out. (in the driveway ) but swapped that out with a spare I had and have been good ever since. If you lock the front end I would say just watch the bouncing when your out wheeling. Bouncing = Breaking!!!

Good Luck!

Atmos

Zoid your rig is awesome man! the only thing is I dont know how to stroke it I'd have to pay someone to do that which sucks and I think I'll be trying to stay at 4.5 or 5.5
I'm definitely doing that setup tho right from the getgo
you need to start a build thread

xjmarc

I had a D35. The 4.56s would be ok but 4.88s would be better. They chart doesn't account for weight of the tires and the fact that your even less aerodynamic when lifted.

XJmoneypot

im running 4.56 grars with 35's, and i tear in to it never, never had a problem at all, it will take it the only bad part is the d30 and components on them can get bent pretty easily