I want my lowend back after wheel swap.
 

I put 30's on my XJ. Now I want to get most if not all the lowend performance back by changing out some gears. Here's where my knowledge lacks. What do I change? Do I change something in the transfer case, transmission, or in the diff housings? So I need to know: what I need to change (all parts required please), where to get the parts, and how much money I should expect to spend for the labor if I choose not to do it myself.

Thanks in advance.

with 30's you should not lose that much. I would look into a full tune up first.

if you plan to go bigger down the road wait until then. if you NEVER plan to go a bigger tire 30/31" tire

what you have.....what you could switch to:

3.07....3.55
3.55....3.73
3.73....4.10


again this is if you want to.... but the $2500 it will take to re-gear to me is not worth it if you plan to go a bigger tire.

and they would be the differential gears

Im going to try and say this nicely. if you have to ask those questions you should not be attempting a gear change by your self. Find a reputable shop and start pricing. That is not much of a tire change, so I would probably reccomend a 3.73 gear. without looking at a calculator I think that would put you back to near stock. although man, probably not worth the money. I drove on 31's and it was barely noticeable. I dont think enough to re gear anyway.
oh if you want to look at parts, first you will need to know which rear axle you have. if you post the year we may be able to narrow it down. then go to a site like www.justdifferentials.com and browse around.
You will need a ring and pinion set for each axle. (dana 30 front) a master overhaul kit for each, and a new carrier for the front dana 30.

first thing need is fat wallet ,lol

agreed. swapping out gears is alot more in depth than any other type of vehicle maintenance.

another thing to look into is figure out what gear ratio you have, then buy a set of axles for a couple hundred bucks with the next lower (numerically higher) gear ratio.

and like mentioned, there really isnt that much of a difference stepping up to 30's, or even 31's. definitely not worth swapping out gears.

X2. Alot of money and you wont notice a gain. You shouldn't have noticed a loss with that small of a change in tire size. Maybe a tune up os needed.

Thanks for the info. It wasn't a matter of lack of ability to work the truck. I just jumped out the truck frustrated and onto the computer to figure out where to start. I just needed to know where the the work was needed, then I would enlist friends that are into truck building to help out.

The A/C pauses going on overpasses on the highway when I have passengers. The 19' bayboat on a single axle trailer sort of sucks to pull. Also, it seems the tranny is a bit confused.

$2500!!!??? Okay, I guess I can live with it. I will do that tune up. In truth, it doesn't run as smooth as it used to.

Thanks guys.

That's why they dress that way lol.

:lol:

Hope you have a cooler on the tranny if your pulling often, heat is about the only thing that kills aw4's

If you tow and have capable friends than that may make the difference. Its just not a big change. Parts wise, I shopped and got my gears and kits shipped for $715.
Now keep in mind someone who can wrench and build stuff, doesn't necessarily have the knowledge to change gears

Setting gears is like build an engine, Its all about the fine details and getting it right the 1st time so you dont waste your money

You shouldn't need a gear change for 30" tires. In fact, your speedo is probably just now dead on. That's the way it was with mine after going to 30" from 225/70/15. Maybe the ones you had on there were too small to begin?

Having said that, you still haven't given us any real info about the Jeep. Things might be different for a manual, but I know I didn't feel any difference in power or mileage until I went to 32s. But then, I never towed w/ the XJ. At 33" tires I had mine regeared to 4.56 & that's where she stays. Still sux at everything, but I wouldn't trade her for a luxury car.

x2


OP - what gear ratio do you have? it may be worthwhile to look into a JY set of axles with the next deeper ratio like i said before. you could be in a set of axles for under $400, then have a set of spare axles if anything ever happens. something to look into

bored throttle body will help a lil bit!!