Want to go from 30" to 31" tires.

Jeff-97XJ · Mar 13, 2016

97XJ, 4.0, 231J, 3" Old Man Emu lift. 435K miles.

I currently have a 3" lift and running 30" tires.
I have original gearing.

What would be involved in putting on 31" tires?
I'd really love to have bigger paws, but don't know about gearing issues, speedometer issues, control arm issues, lift issues, fender trimming issues, etc.

Any help appreciated.

TRCM · Mar 13, 2016

And I thought my 88 was old @ 380k on the ticker.....but you got me beat.

gearing will be ok, but tire fit, you will have some rubbing off road unless you bumpstop it properly

Speedo may still be close. I put 31's on my 96, and it is only off my 2 mph @ 60 with no correction
the rest is up to yuopu. not needed, but not a bad idea either.

You may need a SYE and a custom rear driveshaft

Gunter · Mar 13, 2016

the offset of you wheels will effect if they will rub. and the back side of the front fenders may well rub slightly. but the "slight" rub can slice your tires.

Johnnie Walker · Mar 13, 2016

31x10.5 wheels fit on stock wheels. Since you have 3" lift that should be fine.
Pending, LCA's and steering stops, tires may rub a bit.
Bumpstops definitely need to be considered.
I like the fact that 10.50 wide tires tuck nicely in the rear

Dubster · Mar 13, 2016

3 inch lift with 30's? I ran 30's stock. 31's now with 2 inch budget lift.

Dub

yossarian19 · Mar 14, 2016

3" & 31's shouldn't give you any trouble at all fitment wise.
My experience, with a 4.0 / auto trans / factory gear ratio, was that 31's sucked notably worse with acceleration & a bit more suckage with braking, too.
Some people will say it's no different than 30s or stock. I suspect they are flatlanders.
With 31's, my Jeep couldn't keep up with traffic going up a "meh, nothing special" local hill.
In factory trim, the same Jeep surprised me with how easily it did 80 mph on interstates in Utah and could pull a small travel trailer up the Rockies like it wasn't there.

CarbonXJ · Mar 15, 2016

yossarian19 said:
3" & 31's shouldn't give you any trouble at all fitment wise.
My experience, with a 4.0 / auto trans / factory gear ratio, was that 31's sucked notably worse with acceleration & a bit more suckage with braking, too.
Some people will say it's no different than 30s or stock. I suspect they are flatlanders.
With 31's, my Jeep couldn't keep up with traffic going up a "meh, nothing special" local hill.
In factory trim, the same Jeep surprised me with how easily it did 80 mph on interstates in Utah and could pull a small travel trailer up the Rockies like it wasn't there.

This is why i went back to 30s on my 4" Lift currently. 31s just suck for me. It's night and day on stock gearing. In the future when I lock the front I'll regear and move up to 31s.

yossarian19 · Mar 15, 2016

I agree. For whatever reason, 30x9.50 tires seem to drive *much* closer to stock than 30x10.50's.
In a BFG AT, a 235 series tire is 36 lbs. A 30" is 39. A 31" AT is 43 lbs. I wouldn't have thought 4 lbs rotating mass and 1/2" of radius could make 31's feel so slow but, yeah, feels a lot slower than a 30" tire.

Want to go from 30" to 31" tires.

Jeff-97XJ

NAXJA Forum User

TRCM

NAXJA Forum User

Gunter

NAXJA Forum User

Johnnie Walker

Piece of Fish!

Dubster

NAXJA Forum User

yossarian19

NAXJA Forum User

CarbonXJ

NAXJA Forum User

yossarian19

NAXJA Forum User

Similar threads