xjbaldy

How much power loss can I expect, or loss of mileage? It seems most of you guys got gears, did you guys install yourself or have someone do it? I can imagine it could be a pain in the ***. I am pretty sure I got 3.55 gears (96 4.0, tow package) this is going to be my DD what do you guys think?

91xj

driving on flat surfaces isnt bad. theres still plenty of power. its when i go to the mountains that i wish i had gears. up the hills, its not so great.

Brad M.

Agreed. /\ /\

When I had my 3" lift and 31's there was definitely a noticeable drop in MPG and overall power, ESPECIALLY on hills. I would recommend running an auxiliary tranny cooler like the B&M if you're going to stay at 3.55's or your tranny will hate you. When I went to 4:10's the difference was awesome. Power was back, MPG returned to pretty much stock. The 4:10's and 31's combo is a great combo.

If you live in a mountainous area like I do, you will want to regear.

xjbaldy

Is installing new gears hard or should I just leave it to the pro's, I know basic stuff, what would it run me to have a shop install them?

Brad M.

Depends on your level of experience, available tools (some very specific tools needed for the job), and whether you want to take the time to do it.

My first re-gear I had a mechanic friend walk me through it and it took an entire Saturday. If you're going to tackle it on your own, you really should research a TON before you attempt it, or have someone who knows how to set up gears help you. Otherwise, pay a good shop to do it. You can expect to pay roughly $400-$600 per axle for parts and labor if you have a shop do it. Well, at least around here.

This link is hands-down the best write up on doing gears I've come across;

http://www.pirate4x4.com/tech/billavista/Gear_Setup/

xjbaldy

muddpigg

i run 31s and 3.55s with no problems but i live in new jersey = no mountains. fuel economy wasn't very noticeably different from stock 225/75s to 31s and at interstate speeds it's no problemo cruising 70mph. you doing any kind of lift or new rims with the new tires - you will rub your lower control arms with 31s and stock rim backspacing and flexing will rub body parts, just so you know. plan on a few more upgrades to really do it right...

superj

i thought tow package cherokee came with 3.73s in the diffs?

if you want to know, lift up the back and put it in neutral. then just mark a chalk line on one wheel and hte driveshaft and rotate the shaft. count how many turns you get for one rotation. if it ends on half then you know yo ugot 3.55. if it ends on 3/4 then you know you got 3.73.

i wish i had 3.73. you want a sleeper cherokee, put 3.73 in with stock tires. light to light you will embarrass alot of people

captainwoot

I also run 31's on stock axles 3.55 ratio works good, no noticible power or mpg loss

xjbaldy

Yeah I am putting on a RE 3.5 inch superride kit, and an SYE but the costs are adding up...but I am not near the truck right now (iraq) so I am havin my dad take it to the shops for me. I live in WA state and there is a lot of hills, and I like road trips. So i am just tryin to make the truck as DDrivable and reliable as possable

xjbaldy

Did all cherokees with the tow package come with 3.73s?

FASTMETAL

i still have plenty of power, but my gas milage dropped off A LOT,, went from 16 to lucky just over 11mpg,, i will be doing gears

cob24

If you are at fort lewis, Im about to do a three in lift and 31's. I will let you know how the drive is here with that set up. If you arent at fort lewis I dont know any of the other terrains round here.

xjbaldy

Sounds good, I am not at lewis, I am stationed out of drum, but the jeep is in seattle...where I am going to live when I ETS. bout 4 more months YEAHA!!!!

superj

from what i have read, that is the story.

check your how i said though to verify. that is how we check on bmws if the diff has been replaced in the past. factory installed diffs have the ratio on the tag and dealer replaced do not.