yeah, that could be. Seems to make sense. Our OD is .75 (at least for 23 spline AW4 outputs). That puts me around 1700 (more like 1850 using a more realistic 32" rolling height) and that sounds about right. I know at 70 when OD kicks in its hovering real close to 2000

 

The chart would be correct in 3rd with torque converter locked.

 

Bookmark it, Use it:
http://www.grimmjeeper.com/gears.html

 

I personally run 5.13's on 36's and never drove it on the road, but at time I wish I had more gearing on the rocks... thats why I did a doubler

 

consider this, a number of guys run 4.88s on 33s, which puts you higher than 5.29s on 37s. Cruising is still in the 2500 range which is pretty good. Going more gear than 5.29 might be good here, especially since you run a good chance of ending up going bigger than 37s

 

I'd go with the 5.13's

My axles have 5.13's and I'll be only running 35's my MPG's will suffer a bit but I will still be able to drive it where I want.

 

wait, you suggest 5.13s for him on 37s, then say youre running 5.13 on 35?

 

Get a low low X-fer case and run higher gears. Massive multiplication for wheeling and good highway manners/mileage.

 

Yep, 5.13's will be a tad more than stock on a true 37" tire.

I had my axles already built for another project that was going on 37's but scrapped the other project and am now putting my axles under my XJ on 35's. I'm not going to pull fresh gears when I may jump tire size later on.

 

[QUOTE=fullwidth;1034294]Yep, 5.13's will be a tad more than stock on a true 37" tire.

True but you have to add in the extra weight and rolling resistance plus it now sits higher so less aerodynamic. I'd say 5.29s are a minimum and prob go lower (numerically higher). I'm in the same boat as you with my 4.56s in that I can't afford to swap them so I'm stuck for now.

 

1) Punctuation, please. It helps.

2) What other gear are you running? The lockers are independent of gearing, you've said it's going to be a rock rig, and the "limited street use" will give you some freedom in selecting axle gearing. However, the tyre size will want to be known (you said 37's) and which transmission do you have? The gear ratios in the transmission will also be a factor.

If you were going to dedicate it to rocks and trailer it to the trailhead and back, I'd say to go as deep as you can (I think the D44 will be your limit here - topping out somewhere around 5.5-6.0:1. Gearing for the D60 is low to begin with.)

The two unknowns I'm looking at here are:

1) What transmission?

2) How much anticipated street use? I'm assuming you have an alternate vehicle for a daily driver.

 

If the 44 is a hp 5.38 is the lowest set I've found. But that would be good for 37s.

 

i lived across the street from a guy who had a tj with a d60/44 combo. he ran 5.13's on 37" krawlers it was a trail rig but did take it on the street occasionally. you know for a milk run or the bikini car wash

 

i have an AW4
and as for street use it will be nothing highway really at all but i want to be able to go highway speeds at a reasonable rpm and it will be on a trailer to the trails and just random quick drives is all it will really get

 

New tyres are 37" in diameter (nominal)
Old tyres are 29" in diameter (nominal - 235/75-15 metric is nominally 28-7/8" static diameter, rolling diameter closer to 28-3/8" or so.)

Click this link - http://www.snoman.com/HTML/axlecalc_5a.html - scroll down and use the third calculator (if you were dealing with a manual, we'd recalculate, the 3.07:1 gearing is a horrible mismatch. But, you've got a good start...)

Per that calculator (and several others, I checked,) you're going to want to go around 4.55:1 gearing in your axles. This is perfectly doable without having to swap axles entirely, and most axles you're likely to swap to will still support 4.55:1 gearing (although a carrier swap will be necessary to change ratios that drastically, as I recall. I don't have the carrier break table handy, but you can ask your gear vendor or check online. Or, if you're going to buy locker/LSD carriers, you can go ahead and just order those at the same time anyhow.)