Jeep Gears or transfer case or...

[heavy18]

I'm getting ready to gear my axles and would like to do it just once.

Specs:
- 2000 XJ: Stock engine, tranny, t-case
- 37" MTRs (sitting, waiting, ready to go on!)
- Not my DD but I drive it to the trail, scout-camp, camping, so... (And sometimes the trail is in California, or S. Utah, etc)

I'm considering:
A. 5.13 gears
B. 4.88 gears - if I don't like it, save for a 4:1 case/kit
C. 4.56 gears and saving for a 4:1 case/kit
D. 4.56 gears and saving for some sort of doubler

The new 8.8 is already geared to 4.56, which would be convenient and give me a head start on saving for a 4:1 or doubler. That is my preference, but 4.56s may be a bad choice for 37s, even on the road? (I don't really want to be cresting summits at 40mph)

So, opinions? Experience?
Please, enlighten me with your wisdom!

 

[bryson]

5.13s = great offroad, great around town, not as great as 4.88s on road mileage (still not bad though.)

4.88 = not bad all around, but I think you'd like the 5.13s better.

4.56 = not low enough for 37s around town/on the trail.

Don't wimp-out on the axle gears, because if you don't like them, the 4:1 only fixes it in low range, you still have a slug on the road. If you're having trouble deciding between 2 ratios, pick the lower one and you'll be happy.

No matter what way you go, the doubler or the 4:1 t-case may still be worth it... More so if you have a 5-speed. You might be able to get away without it if you have an auto trans. Doubler would be better, 'cause you'd still have the option of the stock low range for the sand or snow... 4:1s and high RPMs (sand, mud, snow...) do not mix well.

My vote = 5.13s AND the doubler.

 

[bryson]

May have to change my vote whether I like it or not, because I don't think you can get 5.13s for an XJ D30.....:-\ Are you running the stock front end, or something else?

 

[heavy18]

It's an auto trans and I'm getting ready to build up a Waggy D44 for the front.

Thanks for the input.

 

[Gravy]

If you want to use that 8.8 rear, I have a d30 with 4.56's for sale, setup for a XJ. PM me and I'll get you some pics.

4.56's will work great for 35's

 

[heavy18]

If you want to use that 8.8 rear, I have a d30 with 4.56's for sale, setup for a XJ. PM me and I'll get you some pics.

4.56's will work great for 35's

Thanks, I already have a D30 with 4.56s and an ARB - that I 'll sell you if you want!

Yeah, I've already got the 5 37" MTRs, so thats what I'm going with, hence the D44 I'm building...

 

[Gravy]

You'll be hard pressed to keep the d44 front alive unless you run alloys.
but I vote 5.13's if you build a front 44

 

[redXJ]

You'll be hard pressed to keep the d44 front alive unless you run alloys.
but I vote 5.13's if you build a front 44

x2

 

[heavy18]

I figure as I break stuff I'll replace with alloy. I know some guys have trouble with 37s on the D44 but I know others that go years on stock shafts without breakage. Personally, I feel better about running 37s on a D44 than running 35s on a D30, but I know that's a touchy subject.

 

[heavy18]

So, any other thoughts on this one or are 5.13s on 37s pretty much the golden standard?

 

[N8RB8R]

I ran your same setup, 4.0 auto waggy 44's with 4.88 gears and 37 mtrs and was really happy with it great power and good mileage.

 

[ichi-san]

I run 4.56 with 33 MTRs & have the 4:1 t-case - nice street performance in high range - could stand to be lower for obstacles - 5.13 with 37" is about the equivalent.