'01 XJ - Regearing Questions

So I want to change out the gears in my 01 XJ but I don't know enough about what's involved, etc. My questions are:

- What's the stock spec on an '01 (Dana 30, 35 , 40 with what gear ratio)?
- I run 31x10.5 BFG AT with a 3" lift and intake/exhaust mods... what gearing should I go with? 4.10, 4.56, 4.88? I don't expect to be rock crawling.
- what can I expect to pay for parts (no lockers now...)?
- If I change out the gears, how will it alter my MPG (this is a DD)
- where can I find the parts.

This is my 4th Jeep in 6 or 7 years. I have plenty of experience under the hood and off road, but never had the dough to change out the gears so this will be my first axel job. Any suggestions?

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'01 XJ Sport 4.0L, 31x10.5 BFG AT, Rusty's 3", bored-out TB, TBS, K&N, Flowmaster 40 cat-back w 2.5 pipe, etc

what kind of tranny you running

i would say 4.10's for 31's

If you don't think you want to go bigger than 31's than the 4.10 gears will be fine and you can find them in 4 banger xjs with an manual. The auto 4 banger should be 3.73 which is not too bad either. What do you have now (tranny, gearing, etc)? If there is a chance that you will go to 32's or 33's than get the 4.56 gears or even 4.88s if you swap out your rear axle for a dana 44. If you have the 8.25 back there than your max will be 4.56 gears.
Troy

As far as I know it's a stock transmission. I would like to have the option to go with 33's in the future... with that in mind, would the 4.10 still be a good choice?

If you don't think you want to go bigger than 31's than the 4.10 gears will be fine and you can find them in 4 banger xjs with an manual. The auto 4 banger should be 3.73 which is not too bad either. What do you have now (tranny, gearing, etc)? If there is a chance that you will go to 32's or 33's than get the 4.56 gears or even 4.88s if you swap out your rear axle for a dana 44. If you have the 8.25 back there than your max will be 4.56 gears.

Since you have the 01', you most likely have the low pinion or standard dana 30 rather than the hp dana 30 so swapping it out for a hp non-disco with 297 u-joints from a 4 banger manual would be a great bang for the buck upgrade and you should be happy with it.
Troy

Big Red said:

Since you have the 01', you most likely have the low pinion or standard dana 30 rather than the hp dana 30 so swapping it out for a hp non-disco with 297 u-joints from a 4 banger manual would be a great bang for the buck upgrade and you should be happy with it.

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Thanks SO much for the help!

Say that I did that... what would I be looking at having to do in support of the new axel? (can you tell I've never done axel work before?) Being a D30 for a HP D30 would there be any other parts that I would have to swap to get it to work?

If I buy the gears for the front and rear, what else am I going to have to change out?

If anyone knows of a good article on a gear change, I'll read it from cover to cover. I just haven't been able to use my Google powers to find one yet...

First off, your 01 should have an 8.25 rear not a 35. do you plan on doing the install yourself?
4.10 gears is good if your gonna stick with the 31"s. but if your planning on having inchitis which is a very common outbreak, then 33" are choice along with either 4.56 or even 4.88 gears. probably 4.56 gears would be fine on 31"s till you get your 33"s.
where in your state are you located? I have a customer out there that got his gears installed at one man shop out there. if you want I can get you a #.

Rawbrown said:

First off, your 01 should have an 8.25 rear not a 35.

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It may have a D35 if it has ABS... my '01 does, and my '97 did.

Well, I just rolled under the dang thing and did a little investigation.

FRONT: says Dana but not discernable if it's a 30 or what. Was marked with "270-0" and 3.55. So, I have 3.55 gearing up front I guess, but I still don't know what Dana it is.

REAR: No discernable markings besides numbers and a Chrysler symbol. The numbers didn't look to be familiar (like gear ratios or Dana model numbers, etc)

Thanks!

Chrysler symbol would be the 8.25... it has a flat bottom edge, right? The D35 has a rounded bottom.

The front is a Dana 30, the only axle ever offered in the domestic XJ.

Yep, it's a flat bottom.

That axle is limited to 4.56 gears, which would be good for 33's. Some people like that ratio with 31's, it all depends on your driving style. No sense in doing it twice, so you might as well just do that. It is a decent axle strengthwise, with 29 spline shafts and a beefy housing. You'll need a ring & pinion set & rebuild kit.

D30 would require the ring & pinion set, rebuild kit and a low ratio carrier.

Enjoy!