I don't think people realize that an AX-15 is a manual transmission with different gears.

Honestly this is one of my biggest pet peeves. This is how misinformation happens. This situation is how things like "exhaust back pressure" myths got started.

Folks read something on the net, not knowing the full story, and now think its law, even tho its incorrect.

Not to be a dick...:/

No worries, glad you pointed that out. At least people are getting better about posting what their setup is so it's easier to know the relevance of the info!

I'm glad someone who has had the exact situation has chimed in. That makes me much more cautious now. I might look for a set of 3.73s now. My plan was to eventually go to 33s, but being a college student, my money doesn't really go to my jeep unless it needs too. That said, I'll probably have my tires for the next 4 years or so before I swap to 33s. At that point, I should have a real job and the money to pay for another regear.

^^Sounds well thought out.

Save some cash and look for used axles - if you find ones in decent shape, it's a lot cheaper to just swap in 3.55:1 geared axles and then 4.10:1s later down the road, of course depending on what it costs you to refurbish them

I like the axles I have, 29 spline 8.25 and a Hi-pinion D30. Sure, 3.55s might be pretty cheap, especially since I wont need a new carrier, but I'd rather spend a bit more to do it right so I don't spend the next 4 years questioning or regretting my decision.

What are you talking about? Why would you rip open a stock axle to install stock gears for however much the labor costs, when you can just install another stock axle for less? You also build spare parts that way

It's free to put gears in guys

I said I'm going with 3.73s, how many sets of 29 spline 8.25s and HP D30s are sitting around with 3.73s? Not too many, especially around me. Sure, I can probably find a set with 3.55s easily, but the difference from 3.07s to 3.55s is not going to be a huge gain. I don't want 3.55s Sure it might help, but I want it right for the next 4 years, not just kinda better and to have some spare parts I'm not gonna use, or have a place to store them. I don't need extra axles, I need the right gear ratio. If I can by chance find a set of axles with 3.73s for a good price, I might swap them, but otherwise, it's going to be easier to just have a set of 3.73s installed in my current axles. I'm not shooting down your idea, I just don't think I'll find the axles I want with the gears I want. You can bet I'll look though.

meh, i'd still go 4.10s even with the AX15. i ran 29s with 4.10s on my AW4 for over a year and i was very pleased with the highway and city driving matters. yes i could still do 70 mph+ on the freeway and still got 19 mpg highway. im pretty sure 29s/4.10s/AW4 is a lower geared combo than 31s/4.10s/AX15 anyways, so it shouldnt be bad at all for you. i know you're probably set on 3.73 but it just doesnt seem like much of an upgrade considering 3.55 axles are dime a dozen.

Hi,
I'm thinking of regearing as well and going from 31's to 32 or 33s.
I have a 99 manual trans, with 3.07 gears and 31's and can cruz at 70mph reving at 2000rpms in 5th gear - this gives me good gas mileage for a Jeep and if I need more power going up a hill I drop it down to 4th and run the revs up to 2500+ till I get over. If you want more power in 5th gear I would think that you would want to stay in a higher rpm range wich means numerically higher gears which also means poorer gas mileage.
Why not focus on where you want your rpms to be in 5th gear for the tire size you want and regear accordingly - wouldn't that give you the best all around solution?

It might just be me but why even bother with 3.73s (which are rare enough you might need to buy them new), to upgrade to only 4.10 later? 3.55 on 31s -> 4.10 on 33s would maintain similar power, likewise 3.73 -> 4.56 follows a similar logic of being geared deeply. My point is you're talking about going from geared deeply to almost back to stock again (higher RPM but the increased rotating mass of the tire will suck away some power) once you upgrade.

No you aren't, fix your speedometer lol

Effective gear ratio = stock tire diameter (in inches) X current gear ratio / new tire diameter.

This will tell you what gearing your Jeep "acts" like it has. By plugging different gear ratios into the "current ratio" slot, you can try to do the math till the final result is as close to the stock ratio as possible (3.55 for Auto, 3.07 for Standards)