Newbie tire size question

[live2_4x4]

Will I break something if I am running 31" tires on my 94xlt and need to use a stock size 235/75/15 spare in an emergency? I have stock diffs, open front limited slip rear.

 

[mrboyle]

With a LSD (Limited Slip Differential) you don't want to run different size tires. It will wreck havoc on the clutches in a very short amount of time. But there is a way to get away with running a smaller spare. Just put it on the front. This may requior changing 2 tires (if you have a flat rear), but its the only way to insure you don't damage the rear diff.

 

[live2_4x4]

Cool Thanks

So... it can be done, just a little more work. I like it
Thanks

 

[Eneurb]

So... it can be done, just a little more work. I like it
Thanks

I wouldn't recommend using 4X4 with the spare tire on...

 

[live2_4x4]

Why?

Ummm... o.k. but why not??

 

[1993xlt]

It can bind up and break an axle joint, d-shaft or t-case. Even though it's an open front diff the front d-shaft will have to spin faster than the rear. The open diff will balance out the speed difference of the left to right tire size difference and will actually be turning faster than if both tires were the same size. I'm not sure if that explanation makes sense? Think of it like this: If on the rear you had 35's, each tire will turn at 600 revolutions per mile. This mean that the differential will have 1200 revolutions put into it if you were to drag the truck for 1 mile. Now on the front you have a 35" tire on one side and a 33" tire on the other side. The 35" turns at 600 revolutions per mile and the 33" at 635 revolutions per mile. That is 1235 revolutions put into the front diff compared to only 1200 into the rear diff, therefore the front shaft will be turning faster. Make sense?

 

[live2_4x4]

Thanks

Yes with that explanation it does make sense. Thanks for the details.
Glen