Re-gearing
 

Ive decided on a lift and 32in tires. Im ok with regearing if i have to. Ive got a 5 speed so my first question is should i have to do regearing? And if so then should i put a chrysler 8.25 rear end with 3.90 gears or 4.10?

You won't find 3.90s and if you have a manual save some coin and get axles out of an auto. The 3.55s will be good for 32s. Much better than your 3.07s.

Or...

Buy a ford 8.8 with 4.10 gears and an lsd from the scrap yard and then regear the front to 4.10.

4.10s with 32s and a manual and you'll be pushing some seriously high rpm on the highway.

How so? 4.10 gears with an AX-15/NP231 combo and 32" tires yields a 5th gear rpm of 2211 @ 65mph

The standard 4.56 gears for 33" tires and an AW-4/NP231 combo gives a 4th gear rpm of 2263 @ 65mph

And for the sake of arguing... the 4.10/32" in a 5 speed would only be 77rpm more in 5th gear than 4.56 gears and 35" tires with an auto trans

So how do you figure?

It's not to bad with 4.10's. 2200-2300@65

I'm pushing 27k with 4.56s and 35s with an AW4 in OD.

27 thousand? You should only be turning 2134rpms at 65 with your gears and transmission.

You may want to re measure your tires, because that's not even close to right

alright. 3.55s sound good. Im not going to be doing a ton of offroading or serious offroading when i do go. Its mainly just gunna be for to and from school and work. I just dont wanna have my xj feeling bogged down. I definitely wanna get the 3.07s out though. Cause they even feel bogged down on the highway at times with my 30 in tires i have on now. Are 3.73s a possibility though? I dont mean to sound ignorant with this stuff im just new to all the mods such as axles and sye's for bigger tires and stuff.

http://www.jeep4x4center.com/calculators/index.htmif you find a 4banger xj you get factory 410s you might get lucky

thanks a lot man. That chart is very helpful. seriously. and that would be nice to find. my sisters 97 xj with an auto is sittin in the driveway dead (:/ was a nice car) but i think ill try to yank the gears out of it since its should be 3.55s

Ok this may be a stupid question but where can you find a Ford 8.8

Best place is an explorer

Just find one in the junk yard and buy it?

Yep, they aren't to hard to find. And very strong

How much do they usually run?

Varies by junkyard.

50-300 normally

Pick-n-Pulls want around $250 (well where I live anyway)
Other type yards could be spendy.
My goal is to score a 8.8 w/410+LSD

This chart is for 65 mph with a 1 to 1 high gear in the transmission! If you want to use it, multiply the answer it gives for your tire and gears by the OD ratio for your transmission AW4=.75, AX15=.79

Yeah get gears before tires I've got 33 and the ax-15 5th gear is just there for looks know its useless

I'm a little confused. I have a 94 XJ with 4.0 w/ auto and a 231 TC. Isn't it an overdrive trani. I think the stock gears are 3.55 (Dana front, Chrys 8.25 rear) If it is an overdrive trani. what gears should I run with 33" tires at 65MPH to keep the RPM in the right range? This is a DD only. Thanks

Hey everyone if get an Ford 8.8 for the rear what will I have to do for the front?

Does the gear package on rough country come for the front and back?