MirageMobile

Anyone have an opinion on the matter:

AX-15 setup using 31x10.5 tires & 3.73 gears vs 33x10.5 tires and 4.10 gears for a DD (80% onroad).

According to this gear calculator, both setups will have slower crawl speeds and lower engine rpms at 65mph when compared to the standard forum recommendations of an AW4 setup using 31s and 4.10s vs 33s and 4.56.

After some calculations and talking to a few forums members, I believe 4.10s and 31s with the AX-15 will be too low of a gearing for a DD.

I'm sitting with 3.07s in a dana 30 HP and dana 35 LSD on stock tires. What would be the best way to go about axle upgrades (never going above 33s, maybe rear LSD and eaton e-locker in front).

1. Hardest part would be finding 3.73s in a HP Dana 30 and Chrysler 8.25, right?
2. If sticking with 3.73s and not finding axles, then I must buy gears for the HP Dana 30, buy a chrysler 8.25 and regear it to?
3. Could jump to 33x10.5 tires and 4.10s (more common gearing to find axles for, correct?).

Can anyone weight in on the handling differences between 31x10.5 and 33x10.5 tires. I could also go to 16" wheels, haven't decided on a tire yet.

s14unimog

I think even 4.10's behind the ax-15 on 33's is a bit low for a daily driver. I run 32's with 3.55's behind an AX-15 and love it. My truck turns 22-2300 at 65mph in 5th.

Gee oh Dee

I like my ax15/4.10s/33s.

salad

3.55:1, they're everywhere. I spent $150 + gas for two complete axles and replaced replaceable bits.

s14unimog

Ya? You drive this on the hwy much? How many rpm's are you turning at 65mph (not speedometer indicated but actual)?

just curious

Gee oh Dee

It was my daily driver up until a couple months ago.

It's been awhile since I've payed attention to rpms, tho. Sorry.

s14unimog

^ the main reason I ask is because you have all of the "would be gearing specialist" (of course not talking about you) who berate the idea of 3.55's for 5-speed owners as if it does nothing for 31-33's. I'm here to say, its a significant difference from a 3.07 on 32's (my truck) and so I can only imagine a 4.10 is substantial, if not result in excessively high engine rpms at hwy speeds.

I literately finished installing 3.55's not but 5 days ago in my D30 and have spent the last 3 months 4wd-less with a 8.25 I swapped in already containing 3.55's. The improvement over the 3.07's pushing 32's was everything I had hoped it would be.

salad

http://www.grimmjeeper.com/gears.html <--- answers all of your questions

I'm loving my 3.55s with 31s. I broke half the **** on my old axles trying to lift the Jeep anyway lol

Gee oh Dee

My first gear was useless when I had 31s and 4.10s. It now seems like stock with a bit more pep than the stock XJ I had.

Josh94xj

I'm running 3.55 with 32s on a ax15 the 3.55 combined with 32s brought it back to near stock. I was on a budget and had the axels so I slapped em in and honestly I love it. I'd really liked to go 4.10 but couldn't afford a re gear. I love my current setup tho and as of now unless I go 33s witch I may since I trimmed fenders and I'm sitting at 4.5 inches of lift, I don't plan to change
It any time soon.

Gee oh Dee

Find some 4cyl XJ axles. They came 4.10, the rear wouldn't be great, tho, as its probably a D35.

OI3R13N

I've currently got my ax-15 XJ set up with 4.10s and 33x10.50x15's. Its been far too long for me to remember what it felt like stock but it is pretty peppy. I got a new speedo gear put in so everything is reading correctly (gps confirmed) and at 65mph im spinning just at 2k rpm. I absolutely LOVE the way it feels and would do it again in a heartbeat. Plus if I ever decide to put 35s on I know I wont be losing much gear wise.

mr white

If you're staying on 31s I wouldn't bother with regearing. If you're going to 33s, I'd put them on and drive it and see if you even need to gear it. Lightweight 33s and ax15 was fine for me on the road, plus cruising at lower rpm saves a bit of fuel.

DTarve23

I am currently in the process of putting 4.10s on my jeep with 35s and an AX-15 and I am confident that it will be plenty for mild wheeling and highway mileage. Its all in preference and where you are located some people can get away with a little higher gear because their daily drive is not that far.....like here in Texas where I live it is 20 miles round trip just to the grocery store

RkyMtnH

I had the same set-up in my old Jeep. Not enough to stay in 5th gear on the highway.
Constantly going from 5th to 4th when I got to any hill.
But you are correct about, "some people can get away with a little higher gear because
their daily drive is not that far." That and living in an area with small to no hills.