Topic: stock spare, with larger tires

[Chad]

When I upgraded to larger tires I didn't feel the need to fork out another $175 for a fifth tire for the spare on the back.  I moved up from stock 29" i think to 31".  If for some reason I get a flat and I have to put the stock spare on the back can driving with one 1 29" and 3 31" tires do any damage to my vehicle?

[SMC4WD]

I wouldn't recommend doing it for a very long time, but in a pinch...
It shouldn't be a big deal if you have open differentials.  If you've got a limited slip it will prematurely wear out the clutchs.

It'll destroy a locker.

I had to do it once.  In fact, at the time I had 33's and I messed up three of my four.  I used my spare, I plugged another one, but when the third tire went out on me I did what I had to do.  I borrowed the only spare that was my same bolt pattern.  It was a 35" tire.  So I aired the 33" tire all the way up, and the 35" all the way down.  

Search around for a used, bald tire.  It shouldn't be that much money from some tire shop.  Check at your local Les Schwab or Discount.  Even a crappy all-terrain would be better than nothing.

[Chad]

that sounds like a helluva story the day you lost 3 outta your four tires.  thanks for the advice i'll look around i could probably trade a tire shop the tire on the back is still brand new.

[Jeffy]

I agree with getting a full size spare.  Although 2" difference isn't going to be that bad.  Like he said, a locker will not like it but there are ways around it.  If you're open diff'ed it shouldn't matter but you should still consider the spare as a temp. solution.

With a spare, it won't matter is the wheel matches.  It won't matter if the width is off either.  I finally got fed up with a poly spare and my 35's that I bought a spare.  I went with a 34x9.5R15 TSL. (TSL bias ply runs taller then sidewall) Goes well with my 35x12.5R15 MTR's.  (Radial MTR's run smaller then sidewall.)  I have a but of weight and space with the tire over a full size.  Although with a 31 it would make sense to just get a 31.

[chrisfranklin]

Good Post!!!

I was getting ready to install front/rear Aussies on my rig with the 29s.  Spare is a 205/15

I know the 35" guys are going to try to find a way to diss the less gangly 29s ...  

But, still, I didn't take the smaller spare in to account with the auto locker install and would probably pay big if I ever had to reach for the spare (or I'd have a mismatched-tire-diameter-epiphany while 100 miles out in the middle of knowhere with no help to be found)

May have saved me some money with this post.  "Much grass" to you!   :D :roll:

[Dare2BSquare]

It looks like a larger tire than the 28" spare that came on the wrangler would have trouble clearing the third brake light if you mount it on the existing tire carrier.

[Jeffy]

Good Post!!!

I was getting ready to install front/rear Aussies on my rig with the 29s.  Spare is a 205/15

I know the 35" guys are going to try to find a way to diss the less gangly 29s ...  

But, still, I didn't take the smaller spare in to account with the auto locker install and would probably pay big if I ever had to reach for the spare (or I'd have a mismatched-tire-diameter-epiphany while 100 miles out in the middle of knowhere with no help to be found)

May have saved me some money with this post.  "Much grass" to you!   :D :roll:

Running a tire is that significantly smaller then your other tires with a locker is asking for trouble.  The locker will have trouble because the rolling radius of the two tires is different.  THe smaller tire will either have to unlock or get dragged by the larger tire.  What usually happens is the tire gets dragged a bit and the locker freaks out and trys to unlock and locks then unlocks.  This can happen with as little as .5" difference in height.  Offroad you might not notice it as much but onroad you would.  Also, offroad, you could air down the other tires and keep the smaller tire aired up.

Now if you only had one locker you could swap the spare to the unlocked axle then move the matching tire to the locked axle.  But since you're running two that's not an option.  You could carry your side and spider gears with some RTV and gear oil.  Then swap out the locker in a few mintues and then swap the spare on but that would be a major PITA.  Or you could hope and pray for another Jeeper to drive by with a 31" spare that might be willing to help.

[Jesse-James]

It looks like a larger tire than the 28" spare that came on the wrangler would have trouble clearing the third brake light if you mount it on the existing tire carrier.

I have a 31" spare on my YJ, Barely clears it, but if nothing else you can unbolt the light frame and put washers in to raise it.

[Mozman68]

It looks like a larger tire than the 28" spare that came on the wrangler would have trouble clearing the third brake light if you mount it on the existing tire carrier.

31" clears it fine....I should know as it does on mine.  May not look like it from this angle, but the whole light sits JUST above the tire.