smtippin

Why does the AX-15 only have 3.07 gearing when autos had so much more? When I consider upgrading, should I use different gears than folks with autos? I'm planning on running either 32s or 33s, maybe just 31s though for a while.

Thanks,
s

winston427

The different gear ratio for the axles was to keep everything in sync with the different gearing in the transmissions. Also to make up for the lack of horsepower in the 4 cylinders which got the 4.10 gears.

SeriousOffroad

The gear ratios (1,2, 3, 4, 5th) are very different than those of an AW4, as is the final drive ratio. Standards can always stay 1 size higher (numerically lower) than a comparably equipped automatic.

smtippin

Frank,
You're Avatar has more insight into this topic than I do. Can you break that down for me a little bit? With my current gearing, what is the largest tire size I can go safely?

Also, Can you post a pic of one of your bumpers for me? I'm interested in buying one if taxes pay off for me. How much do you want for one of those? I wish they were boxed in on the bottom and had the tubing for a brush guard. Still very very nice though.

s

fishtaconc

check this out http://www.accuautoparts.com/calculatorfin.jsp

96_xj

just my 2 cents. but i run 33/12.5r15's with my 3.07 gearing. Highway is fine in 5th it runs about 1700-2300 rpms and i can drop into 4th and pass if need be and i never go over 2500 in normal shifting and 3500 is my personal red line and my jeep drives just fine with my 3.07's on the road and off road in rock crawling and in mud/snow.
as a side not tho i also have an intake with throttle body spacer, upgraded ignition system, performance injectors, and custom exhaust.

5-90

Probably misguided.

Stop using fifth gear, and compare the fuel economy you get that way. You'll probably note an increase - I did.

The 242ci/AX-15 pairing would have been better given 3.73:1 gearing or so than 3.07. The 3.55 gearing paired with the AW4 worked neatly, but the 3.07:1 was just too damned low...

Ritter4.0

I have stock 3.07's and can't even touch 5th gear with my 33's until well over 60mph, I rarely go over 60. I can however ride 2nd all the way to about 45mph, which is really not a good idea.

I plan on regearing to 4.56 (about equal to 4.88 and 35"s with an AW4), mostly because I plan on 35's in a few years, but also because I want the lower gears.. I am going to swap out my D35 for an 8.8 and my disco D30 for a built non disco D30 first though.

Cherokee

well one plus is its pretty easy to upgrade to a 3.55 if you want, because you just have to find a normal automatic xj and youre good to go. can't get any worse so anything helps!