Baystate Jeepers

johnsxj wrote:think about how long you'll be running 31"s before you'd be going to a larger tire.

2x... The auto transmission is pretty forgiving offroad and performs well with lower gear ratios than a manual.

If you want to get to 33" tires someday I would do 4.10 or 4.56 gears. I ran 4.56 with 31x10.50 TruXus tires for a while and it was fine.... Tranny never down-shifted out of 4th gear on the highway and the engine ran higher revs and I got a few less MPG on the highway. If you want to get bigger than 33" tires someday you'll want 4.56.

You've probably got a 27-spline C8.25, or D35. If you have ABS, then you've got a D35.

If you have a C8.25 (this is better than the D35) and also upgrade to 29-spline axle shafts, which are a bit stronger and commonly available (was a stock application in '97+ XJs). If you are going to try to upgrade to the larger shafts you'd need new tube seals + bearings, but they are cheap and easy to do if you're re-gearing anyway.

If you have a D35 you may want to consider replacing the whole axle and putting a 29-spline C8.25 in from a later model XJ, since you're going to re-gear it anyway.

JW

Its up there, 208,xxx.

I am leaning towards it being 3.73 since it looks like the trailer hitch looks as old as the jeep. Never know, could be 3.55 too. Hard to tell if the towing is stock or not.

Jack up one corner, put the trans or t-case in neutral, rotate the tire 1 time while counting how many times the driveshaft turns (mark it with some tape or a zip tie to see it better!) about 3 1/2 turns = 3.55, about 3 3/4 turns = 3.73

connorc88 wrote:I am leaning towards it being 3.73 since it looks like the trailer hitch looks as old as the jeep. Never know, could be 3.55 too. Hard to tell if the towing is stock or not.

The 3.73 is fairly uncommon for XJs.... I've read that ratio was available with the factory tow package, but I think that most of the tow package could be added as an option. I've never found a 3.73.... only 3.55 or 3.07.

JW

The other thing to consider if you change ratios is carrier break. The D30 front axle uses one carrier for 3.55 and numerically lower gears and a different one for 3.73 and numerically higher gears.

A potential alternetive might be to do some junkyard searching and look for a Cherokee with the 2.5l four popper. All of those used 4.10 gears in the axles.

ZAEDOCK wrote:We have a few XJ's here. We usually send them to the store to pick up groceries for the Baystate cookouts.

By store you mean the auto parts store, and by cookout you mean when we all have to stop because a Wrangler breaks...

88jeepxj wrote:

ZAEDOCK wrote:We have a few XJ's here. We usually send them to the store to pick up groceries for the Baystate cookouts.

By store you mean the auto parts store, and by cookout you mean when we all have to stop because a Wrangler breaks...

you're going to fit in just fine.......

Cool thanks for the info guys. What do you reccomend for a 3'' suspension lift? Preferably one with full rear leafs since my stock ones probably wont last long off road with 208k on them.

connorc88 wrote:Cool thanks for the info guys. What do you reccomend for a 3'' suspension lift? Preferably one with full rear leafs since my stock ones probably wont last long off road with 208k on them.

If you want to go 31" tires, 3" would work... I spent a lot of time thinking about 3" vs. 4.5" back when I was going to do my first lift.... I went with a 4.5" lift and I was really happy with 31" tires -- minimal rubbing if you get the right bumpstops and you get tons of flex. Was less work when I wanted to go to 33" tires, too.

It is a lot of $$$ to replace major parts if you want to go bigger "some day". Suggest thinking hard about where you want to be in the future and plan to get their incrementally.

With an XJ a 3" lift may be able to get away without an SYE. Probably not in a 4.5" lift.

JW