Stock Spare

Average Joseph · **Posted:** Wed Apr 26, 2006 7:05 pm

Might be a dumb question but...

Is it o.k. to use a stock spare with 31's? I obviously don't know crap, but I figured it might be alright if it goes on the front (because of limited-slipin rear) and no 4wd. I'll be getting the full size soon, I'm just wondering about what to do in the mean time.

unixxx · **Posted:** Wed Apr 26, 2006 8:24 pm

Should be fine temporarily as long as you put it on the front and are in 2WD. If you're off road in 4WD you're kind of screwed though.... Hey, how'd you get 31's to fit?

Average Joseph · **Posted:** Wed Apr 26, 2006 8:33 pm

Frankenlift!!!

As far as I can tell, some folks are actually running 32's - 265/75 (albeit with alot or rubbing). I actually have 30's and am about to step up to 31's... Hopefully they'll fit!!

jason thompson · **Posted:** Wed Apr 26, 2006 8:39 pm

an off size spare will not matter off road in 4wd with open diffs it will be kinda like turning all the time if that makes sence?
when you turn one wheel goes faster than the others so will a smaller wheel so if you have no trac loc or true after market type LSD than it would be ok but i would not use a 30" spare if i had 33"
if you have a full locker you are ?OL because you need a full size MACHING spare with about the same miles
mm count

Jeepjeepster · **Posted:** Wed Apr 26, 2006 8:46 pm

jason thompson wrote:

an off size spare will not matter off road in 4wd with open diffs it will be kinda like turning all the time if that makes sence?
when you turn one wheel goes faster than the others so will a smaller wheel so if you have no trac loc or true after market type LSD than it would be ok but i would not use a 30" spare if i had 33"
if you have a full locker you are ?OL because you need a full size MACHING spare with about the same miles
mm count

That is all true but its still not a good idea to run a smaller tire even with an open diff. The smaller tire causes the diff to heat up b/c the spider gears are always turning. It would be fine for short distances.

unixxx · **Posted:** Wed Apr 26, 2006 9:14 pm

Sorry, I was thinking 31's were bigger than 265s for some reason. I've got a Frankenlift with 265/75R16's and an ARB with absolutely no rub now. I completely flattened out the pinch weld and heated up the wheel wells with a blow torch to bend them into shape. It's definately possible.

Average Joseph wrote:

Frankenlift!!!

As far as I can tell, some folks are actually running 32's - 265/75 (albeit with alot or rubbing). I actually have 30's and am about to step up to 31's... Hopefully they'll fit!!

Average Joseph · **Posted:** Wed Apr 26, 2006 9:37 pm

Thanks for the info. It's a weight off my mind to know that I won't be completely effed if I get a blowout. A full size spare is definately in order... just waiting to find a cheap used one.

SethX9 · **Posted:** Wed Apr 26, 2006 9:42 pm

I haven't upsized the tires yet and am wondering...what is this pinchweld everyone keeps talking about? pics anyone?

thx

Taz · **Posted:** Wed Apr 26, 2006 9:47 pm

I would suggest that you not put the vehicle in 4wd with a different height tire on the front or rear. It will be the same as trying to turn a corner in 4wd, the front wheels might be separated at the diff from each other but one of the front wheel will be connected to the rear wheels through the transfer case and it will have to turn at the same rate as the rear. If you are on loose footing where one wheel can slip, it probably not be an issue but I would not do it on pavement or where wheel slippage is not likely. The guys at the tire store actually did this to my wife's truck and the transfer case made all sorts of noise while in 4wd.

Jeepjeepster · **Posted:** Wed Apr 26, 2006 10:01 pm

Taz wrote:

I would suggest that you not put the vehicle in 4wd with a different height tire on the front or rear. It will be the same as trying to turn a corner in 4wd, the front wheels might be separated at the diff from each other but one of the front wheel will be connected to the rear wheels through the transfer case and it will have to turn at the same rate as the rear. If you are on loose footing where one wheel can slip, it probably not be an issue but I would not do it on pavement or where wheel slippage is not likely. The guys at the tire store actually did this to my wife's truck and the transfer case made all sorts of noise while in 4wd.

It would still be an issue. The only time I would put it in 4wd with different size tires would be on pure ice.

Edit: Why the heck would they put it into 4wd. I would go back there and raise heck!

jason thompson · **Posted:** Wed Apr 26, 2006 10:12 pm

Taz wrote:

I would suggest that you not put the vehicle in 4wd with a different height tire on the front or rear. It will be the same as trying to turn a corner in 4wd, the front wheels might be separated at the diff from each other but one of the front wheel will be connected to the rear wheels through the transfer case and it will have to turn at the same rate as the rear. If you are on loose footing where one wheel can slip, it probably not be an issue but I would not do it on pavement or where wheel slippage is not likely. The guys at the tire store actually did this to my wife's truck and the transfer case made all sorts of noise while in 4wd.

dont take this the wrong way but what you are saying is that you can only use 4 wheel drive in mud or loose terain
so when i get in rocks and lock both the front and rear diffs on the TJ then turn to go up a hill where on front tire will have to turn faster or slower than the rear and faster or slower than the other front that this is bad so i should unlock both diffs pray i make the obstical with 1 front wheel in the air and 1 of the 2 backs almost there?

the question is about a spare tire wich you hope to never need but if you do it is only to get you home or to the tire store for a replacement but if it is .5" or even 1" smaller but in good shape it may not be worth the cash for a new tire
and seeing that the font of a KJ should be left open and almost every blow out i have seen on a trail has been on the front
then in an emergency a slightly smaller spare would be ok

unixxx · **Posted:** Wed Apr 26, 2006 10:36 pm

SethX9 wrote:

I haven't upsized the tires yet and am wondering...what is this pinchweld everyone keeps talking about? pics anyone?

thx

The "pinchweld" is two pieces of the body welded together that protrude into the wheel well. The weld is covered by part of the plastic wheel well which takes even more space. This is my weld bent over with the plastic covering cut off:

Since I've taken the sledge hammer to it so it's completely flat and covered it with undercoating.

blackjeep · **Posted:** Thu Apr 27, 2006 12:40 am

if you do blow a rear tire, just move a front to the back and spare on the front, little more work but so what.

...can also air up the smaller and air down the bigger for less difference??? i think so anyway.

SethX9 · **Posted:** Thu Apr 27, 2006 9:18 am

unixx - thanks!

mb818 · **Posted:** Thu Apr 27, 2006 9:34 am

just to add my 2 cents on this one... on the road, in 2WD, i think it would be fine to run a smaller spare for short distances and not exceeding 45-50 mph... again, as long at you don't have an automatic locking diff or limited slip on the same axle as the small tire is on... just think of all those vehicles out there with a tiny "donut" spare... same difference... (edit: and it doesn't matter front or rear because the front drivetrain is ALWAYS engaged from the wheels to the transfer case.. it's disconnected IN the transfer case... i.e. spider gears would still be turning in the front, too even if in 2WD)

now on the trail, where 4WD would be required to make it off the trail... a full size matching spare would be the best bet... i'm not sure i'd want to risk running a smaller spare while in 4WD... think about it... you're already hobbled, and who knows what kind of terrain you'd have to navigate just to make it off the trail.

mb818

Stock Spare

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