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31X10.50


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31x10.50s are no problem on OEM Jeep 15x7 rims, but a 6" rim is too narrow. Yes, you can probably get away with it, but the rim will be pinching the sidewalls in excessively, pulling the shoulders of the tread away from road contact. The only way you'll be able to run with decent tread contact across the width of the tread will be to run at a pressure too low to be safe.

 

As an example, I just looked up the Cooper Discoverer H/T in 31x10.50. The recommended rim width is 7" to 9" and they took their measured specifications using an 8-1/2" rim.

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If I had a 'Back East' body, IE, rusty, I wouldn't hesitate in the least to cut, whack, chop, bang, slam,etc, to it. I ain't choppin a rust free one. A mild lift, 3-4 inches I wouldn't mind. What brought this question on is I got a '88 XJ with brand new tires on it and I wanted to get some use out of them.I could have, and I'm going to now, is just go try it. Last night I just figured it was easier to type than to jack. The XJ has a mild lift and 8" rims.

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(as most of the others), I'd say no way to 31x10.5's on 6" wheels.

 

The width of the wheel is only half the problem,

 

6" wheels have the same 5.25" back spacing as 15x7's,

so the center of the 10.5" wide tire would actually be shifted inward 1/2" further than it would on a 7" wheel with 5.25" bs.

 

= tire would be even closer to the LCA's & rear leafs. (and 31x10.5's on factory 7's are already cutting it pretty close)

 

Back to the width,

I'm running 235/75-15's on those factory 15x6's now (pic in sig :D )

and the 9.25" wide tire bows out noticeably on the narrow rims,

I wouldn't want to try to fit another 1.25" of tire width in there.

 

 

If you get some 15x7's, lots of people here have run 31's on MJ's with zero lift.

Personally, I'd want 1-2" over stock height,

mostly just to keep from having that 'jammed in there' look to the tires.

 

 

As far as cutting, whacking & chopping to fit 31's, with stock wheels, you should be able to do all the (street use) trimming needed with a pair of tin snips on the plastic of the flares.

 

If the 8's the 31's are on now have shallow backspacing (like typical 3.75-4"), you'd have to do more trimming to fit, since they're trying to use the space occupied by the flares, instead of playing nice, and staying inside the wheelwells.

 

Factory TJ 15x8's are also a good choice to run 31's without cutting much.

They have slightly more backspacing than our 7's (5.5"), but since they're wider, the wheel centerline is actually 1/4" further out than the 7's. (for 1/2" wider track width total).

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It doesn't take much at all . You won't even know you cut it .

 

I am using 15x10" 31x10.5" with the 4" backspacing . Now with zero rub . Stock LCA"s and only cutting mostly plastic .

 

The front fender cutting looks better to me anyway . Also allows me to do more aggressive off road driving .

 

I think they should have come that way from the factory , like other Jeeps . Just my opinion .

 

2" offset wheels won't have any inner rub , just outer flair rub .

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Like I said earlier, I ain't cuttin no rust free mj. If I decide to go all out on a rock crawler, I will get a rusty MJ (now where do you suppose I cud find one of them at?) or use one of the dozen XJ'S and/or S10'S I got sitten around. I didn't get the 31's mounted today like I wanted. Spent most of the day at the hospital with a friend. They finally decided she had a upper respiratory virus infection. Anyway that's the second thing on the agenda for in the AM. Feedin the animals is always first. Jim

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I was going to suggest using 30x9.50's instead, but it sounds like you already have the 31's? I don't think running 31's on stock 6" steel wheels is going to work, without rubbing on either the fenders or LCA's, or both. Of course it would work on wider rims, be they stock Jeep or aftermarket, but even then, you'll still have to trim either the fenders or get WJ LCAs.

 

Good luck with whatever you decide to do, and like you said, no cuttin' up a rust-free MJ (at least metal, plastic would be okay)!

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Actually something so obvious completely escaped me until a minute ago. XJ fenders, front, are a dime a dozen. They can be cut and or replaced with MJ. Just don't cut the back ones. Sometimes I just get so far in the forest I can't see the trees anymore.

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I know you don't want to cut anything but , IMHO this looks clean . The only reason I cut the front is because the

metal at the front of the quarter panel is so thin that one good hit and its gone anyway . This is all the cutting I'll do .

Functional and attractive .

Image Not Found

I haven't finished the ends yet and its getting a internal hitch .

Image Not Found

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If my memory serves me right that looks like the parking lot at the gift shop at Garden Of The Gods. And on the fender, looks good. Just needs a banana up the tail pipe. Who used a banana anyway? I always used a tater. :banana:

On the fender cutting, I'm not doing any off roading with it. Just 2 miles of rough, rutted, unmaintained private road from the county gravel to the house.

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I know you don't want to cut anything but , IMHO this looks clean . The only reason I cut the front is because the

metal at the front of the quarter panel is so thin that one good hit and its gone anyway . This is all the cutting I'll do .

Functional and attractive .

Image Not Found

I haven't finished the ends yet and its getting a internal hitch .

Image Not Found

 

Your memory serves you correct . Not the gift shop though , balancing rock !

DJM/78: for just a DD, would you have rubbed your fenders had you not trimmed them? Also, what lift do you have so I can put it in perspective? Thanks.

 

Rymanrph , yes the tires rubbed slightly at the inner fender well and barely at fenders edge . No LCA rub though .

 

DD here in Colorado springs is a little different than the flatlands . They don't take care of the roads here , so pot holes

appear daily . Big ones . The hot to cold extreme that roads suffer makes for a rough ride .

 

Just to get around in town , my wheels take a hammering . My parking lot at work might as well be a registered trail .

I am constantly off and on road .

With a RE 2" lift and a little trimming I don't get any rub with the wheel locked , right to left .

I still get a little with allot of weight to the front or just heading up a very steep incline . Witch is part of DD around here .

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31s in 15x7 Jeep rims work very good and have minimal rubbing on the lower control arms. 31s on the 15x6 Jeep rims might have a bit more rubbing on the LCAs when at full turning lock, but shouldn't be all that bad. Adding a washer behind the steering stop bolt should fix it (or swapping in the WJ lower control arms).

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Today I did what I should have in the first place. Tried it. Parked the donor a rolled, totaled 4WD XJ beside the donee, a 1988 MJ 2WD. Jacked up left hand side of both cars, removed all 4 tires rolled one of the shiny new tires, 31X10.50R15 with the molding pips still showing, to the front of the MJ. Pick up tire and try to place on hub. How in the %*#@*^&% are you supposed to mount these %#*% things when you can't see the lugs? Played, wiggled, cussed, finally got it started. Lug nuts, impact wrench. Now why are they going on so hard? MJ and XJ have same hubs. Just give it another twist. Center cap pops out, only it ain't a cap. It's the center of the rim with jagged edges. Bearing cover on axle showing thru hole in wheel.This don't look good. Remove lug nuts, remove wheel. Surprisinly it came right off. Thought sure it would be jammed on. Observation. The rotor face on the 4WD is flat. Rotor face on 2WD has a hub sticking out about 2 inches. Check wheel. It's a OEM Chrysler, with the Penta something logo and 31.75 15X7J stamping. And a new hole in the center. Put all tires back where they come from. Remove jacks. Go in house and play games on puter. For sale 4 new 31 10.50R15 tires mounted on OEM Chrysler rims $100 Jim :wall: :headpop:

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For sale 4 new 31 10.50R15 tires mounted on OEM Chrysler rims $100 Jim :wall: :headpop:

OEM Chrysler, or OEM Jeep?

 

Jeep used the same wheels on the 2WD and 4WD models. Anything that fits one should fit the other. Minivan wheels, though, aren't the same.

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For sale 4 new 31 10.50R15 tires mounted on OEM Chrysler rims $100 Jim :wall: :headpop:

OEM Chrysler, or OEM Jeep?

 

Jeep used the same wheels on the 2WD and 4WD models. Anything that fits one should fit the other. Minivan wheels, though, aren't the same.

 

I wonder what kind of wheels they are too.

 

When I put a set of Canyons (15x8" TJ wheels w/ the 30" tire package) on my 2wd ft axle (89' with real wheel bearings), the center caps popped off as I was tightening them.

 

The dust cover sticks out too far to use center caps on these wheels,

 

it makes sense if the later wheels interfere, since they had long since stopped using the full rotor/real wheel bearing style hub in 2wd Jeeps by then.

 

Jim, what did the wheels look like?

Might be a good idea to start working on a list of wheels that are not compatible with the full rotor style 2wd hubs. :dunno:

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Newbie to Jeeps here and I have a simple question on this subject. I'm looking at running 31x10.50s on my Comanche once I get it sorted and at least at first would like to run with no lift. I've seen the posts stating that the WJ lower control arms will eliminate rubbing but what about aftermarket lower control arms? It seems like these are all straight and would therefore have the same issue as the stock arms. Are these arms just narrower than the stock arms? If not it seems like even lifting the truck wouldn't fix this issue. Can anyone explain this for me?

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