And is there a recommend gear size to get better gas mileage on a 01 XJ 4x4?

 

Lifted or stock? What size tires?

 

4.5 lift rear leafs, stock tires.. Getting 32 x11.5's when i have the moneydwn the road

 

Also am having vibration problems. In the rear witch I'm thinking is the U joint? Not.to.sure

 

Check the U-joint and iis your XJ standard or auto?

Brandon

 

4.10s will put you close to stock. 4.56 will put you a little over, but will probably get better city mileage. At your height most of the later model XJ's need an SYE to eliminate vibes. A T-case drop may help, but not a proper fix. Also, a crossmember from a manual xj will give you a slight drop, with no clearance loss.

 

Sye? I'm looking to put in 3.73's or potentially lower, does anyone know what the stock gears actually are?

 

do your research on gears. there's plenty of info on this site and i knew nothing before i joined the forum roughly a month ago. it will really help you a lot in deciding on your gears, I've made my choice based mostly on this site alone.

speaking of things i learned from this site, if you have a manual then you have 3.07 gears, auto is 3.55 (unless you have a tow package, then 3.73)

 

im running 4.56's with 33's and love it but if ur planning on staying with 32's id just go with 4.10's and save gas bc 4.56's with 32 wouldnt help with saving gas

 

32's = 4.10's best bet if you're auto to bring it back to that stock feeling. SYE = Slip Yoke Eliminator. A hack and tap SYE or full SYE should eliminate your vibes. A tcase drop or sye is needed sometimes when lifting 3.5" and definitely when lifting 4.5" or more.

 

I have a 99 with the tow package, but only have 3.55s. I have the tranny cooler and the electric trailer brake wire.