Different sized tires same axle?
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Senior User
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From: new braunfels ,tx
Different sized tires same axle?
I dont have the same size spare as my other tires... 4 tires are 31X1050, think the spare is a 235/75. What would happen if i got a flat and put on a smaller size tire? I know u see those donuts and they r smaller so i was just wondering?
Postmaster
Joined: Dec 2001
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From: UT
In 2H with all open differentials: You probably wouldn't notice much when the spare is on. With the spare on the front, you might notice the truck pull to one side a little, but it shouldn't be bad enough to render the truck undrivable.
With Trac-lock rear: Could have more serious negative consequences. The different size tires would cause the clutches to slip a lot more, causing undue wear and tear. This assumes, of course, that there is still clutch material in there to wear. If the clutches are already worn out, then it's like an open differential (see above).
In 4H/4L: Could be a little more problematic. The smaller tire will force one axle to want to spin faster than the other, but the transfer case won't allow such a thing. Hopefully you're never in a situation that requires 4WD while running the spare.
With Trac-lock rear: Could have more serious negative consequences. The different size tires would cause the clutches to slip a lot more, causing undue wear and tear. This assumes, of course, that there is still clutch material in there to wear. If the clutches are already worn out, then it's like an open differential (see above).
In 4H/4L: Could be a little more problematic. The smaller tire will force one axle to want to spin faster than the other, but the transfer case won't allow such a thing. Hopefully you're never in a situation that requires 4WD while running the spare.
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Why would that matter? like the whole axle wanting to spin and the tranfer case not letting it.where You hinting that you wont get as much traction? Becuase if your saying that that will do damage, your wrong....when ever you get stuck and need 4x4 of course one axle will want to spin more then the other, one axle spining and not gettin you anywhere was the whole reason for using the 4x4. When ever you have 4x4 theres going to be more stress on which ever axle at times and shouldnt yeild a damging result,
then again i dont know what you where hinting
then again i dont know what you where hinting
Postmaster
Joined: Dec 2001
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From: UT
I've posted this here before, but to refresh:
I didn't rotate my first set of tires properly, so the fronts wore out before the rears. Replaced just the fronts with same size (235/75R15) different make (fronts were Michelin, rears were Good Year) tires. So I was running mismatched tires. Even on snow or mud, the drivetrain would bind up in 4H or 4L. I would get a periodic "bang" as the tension released, and it had difficulty getting back into 2H. Fortunately, I didn't break anything, but I knew that "bang" wasn't good.
Having a smaller tire at any position while using 4wd will cause tension in the drivetrain. If you're in a situation where you have to choose between using 4WD and walking, you use the 4WD as long as necessary, then put it back into 2H.
I didn't rotate my first set of tires properly, so the fronts wore out before the rears. Replaced just the fronts with same size (235/75R15) different make (fronts were Michelin, rears were Good Year) tires. So I was running mismatched tires. Even on snow or mud, the drivetrain would bind up in 4H or 4L. I would get a periodic "bang" as the tension released, and it had difficulty getting back into 2H. Fortunately, I didn't break anything, but I knew that "bang" wasn't good.
Having a smaller tire at any position while using 4wd will cause tension in the drivetrain. If you're in a situation where you have to choose between using 4WD and walking, you use the 4WD as long as necessary, then put it back into 2H.
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i dont feel imo that one missmatched tire would make that much difference cuz the open diff should take it up in most cases unless theirs equil strain on both tires .. then neather tire is going to "want " to spin .. a 235 75 is pritty close to a 31 .. but.... as far as youre missmatched front to rears .. thay might be stamped the same size but .. not be true to size .. ive seen in the larger mud tires in different brands be different .. 31s be 32 .. ive seen this in 4 wheeler mag shoot outs .. so that could be youre answer hope i helped ... russ
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yeh, thats what i didnt get.
http://videos.streetfire.net/search/...21C38E5E34.htm
heres proof that it dosent damage it. Yes that is a bronco II, looks like its seen betters days though.
That "bang" must have been somthing else.
http://videos.streetfire.net/search/...21C38E5E34.htm
heres proof that it dosent damage it. Yes that is a bronco II, looks like its seen betters days though.
That "bang" must have been somthing else.
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I see what you mean now, ok having smaller tires on one axle and bigger ones on the other. The smaller ones want to spin faster then the rear ones. Yes, that makes sence.
But with one tire that not that same size and gets no traction and the rear wheels getting traction wouldnt do anything, which is what i though you were describeing.
But with one tire that not that same size and gets no traction and the rear wheels getting traction wouldnt do anything, which is what i though you were describeing.
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Elder User
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From: Tampa
bronocIInoob, The funny thing about 4wheel drives. Is that there not 4wheel drive. If you jack up your truck you will find that the wheels on the back spin in different directions. That is a open diff. or a limited slip. Thats why most off roader put air lockers, Trac-lock or mini spools in the diff. Now trucks and mud bugs and so on with small tires in front and big in back have done gear changes so that there is no binding on the axle and drive line plus you never see them on the street if you do they pulled the drive shafts. If you run a smaller tire on the truck you will tare something up and it will be a diff. or a T-case. Most people dont think of the spare when getting diffrent size tires. Out of sight out of mind if you know what I mean.
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But having only one tire smaller wouldnt really matter right? That smaller tire will spin faster and the one on the other side, the full size one would go slower. Right? Im postive having two small one on the front and two big ons on the back with cuase this binding, but just one i dont think would interfear.
Also with the price of tires, i woulndt get a spare ethier. Extra 130 bucks.....sigh. But if i have too if this will occur, then i will have to save up.
Also with the price of tires, i woulndt get a spare ethier. Extra 130 bucks.....sigh. But if i have too if this will occur, then i will have to save up.
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From: Tampa
What happen with one big and one small is that the small tire will drag. The big tire will move at 60 mph the small tire will move at 70 mph the tire small tire will blow out way before the big tire will. The only way and it's not the best way is to carry 2 spare tires of the same size. YOU CAN NOT DRIVE Locked in 4H or 4L! You will have to put two street tires of a smaller size in front on the same axle till you fix the other tire. I'm an owner of a parts werehouse and this is something to think about, If you run 2 tires of a diffrent size the cost of part ot repair the diff. will cost more than the tire. 7.5 thats in the b2 a rebiuld kit will run around 200 buck +/- thats for everything plus labor which running about 75 to 80 buck a hour and book time is about 4 hours. This is shooting from the hip number wize, but it will be close. If your running a 30" tire a 255/75/15 will put you about 1/4 to 1/2 off high wize 31" + 265/75/15 +/- and 32" + 275 maybe 285. Check with your tire shop see what they say.
Last edited by dogman; Feb 27, 2006 at 08:02 PM.
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Ok, im still not paying for the new spare......i know i sed i would be realizing how limted i am on cash.....i cant do it. Im just going to pray i dont need 4x4 when i have a flat. Maybe a can find a crappy used tire the size of the new 32's that i can get at a good discount on eventually. Ill see how im doing on chas. Gotta fix rust first, then um get a muffler, then tune up the engine, then do the lift 2"kit and install the pro comp shocks i want...then ill see about tires. lol Oh yeh i need to become driving age...
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From: Tampa
[ Oh yeh i need to become driving age...[/QUOTE]
That would be good. I have a b2 and it's my play toy for mud and all.
body parts: http://www.autostyles.com/bpbronco28490.htm
Check on ebay for tires and other parts
[/QUOTE]That would be good. I have a b2 and it's my play toy for mud and all.
body parts: http://www.autostyles.com/bpbronco28490.htm
Check on ebay for tires and other parts
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From: Yokosuka, Honshu, Japan
Originally Posted by bronocIInoob
Ok, im still not paying for the new spare......i know i sed i would be realizing how limted i am on cash.....i cant do it. Im just going to pray i dont need 4x4 when i have a flat. Maybe a can find a crappy used tire the size of the new 32's that i can get at a good discount on eventually. Ill see how im doing on chas. Gotta fix rust first, then um get a muffler, then tune up the engine, then do the lift 2"kit and install the pro comp shocks i want...then ill see about tires. lol Oh yeh i need to become driving age...
Hopefully, by the time you get your license... 
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Oh, and dont take my name wrong. I mean noob by as im a noob at a bronco II, or owning any vehicle at that.
Not like im a noob at automotive stuff, im definetly not a noob at that. Ive been interested on that kind of stuff sence i was 5, and ive done my reading/learning sence. If i had the danm patience i could rebiuld the engine on my truck, only following the haynes manual ( and trust me, they arent destriptive). I was sorta new at physics of a 4x4 though, i ask ALOT of qeustions proir to doing somthing as to not destroy stuff.
If only my dad was interested in this stuff....it would help me out alot. but too bad, im just going to have to duke it out with my bronco and fix all the stuff it throws at me.
Not like im a noob at automotive stuff, im definetly not a noob at that. Ive been interested on that kind of stuff sence i was 5, and ive done my reading/learning sence. If i had the danm patience i could rebiuld the engine on my truck, only following the haynes manual ( and trust me, they arent destriptive). I was sorta new at physics of a 4x4 though, i ask ALOT of qeustions proir to doing somthing as to not destroy stuff.
If only my dad was interested in this stuff....it would help me out alot. but too bad, im just going to have to duke it out with my bronco and fix all the stuff it throws at me.
Last edited by bronocIInoob; Feb 28, 2006 at 08:58 PM.