Uneven Tire Tread Depth – Should I be Concerned

[MMerlino]

My truck has 28K miles on it. The tires have about 50% of their tread depth remaining. I picked up a small nail in my left rear that was non repairable due to the proximity to the sidewall. I keep the tires at 80 psi and the leaking tire looses about 10 psi in a week. The tire dealership wanted to sell me a new tire ($254). They did not however have the same brand in stock. I therefore choose to have them use the spare tire which had never been on the ground and put the spare on the aluminum wheel and the leaker on the spare steel wheel.



My truck has a limited slip rear differential. The difference in tread depth between the older right rear tire and the never been on the ground spare is approximately 5/32nds of an inch. Bear in mind the tires are of the same manufacture, size etc.



My concern is will running the rear tires with this amount of difference in tread depth going to damage my rear differential?



Any educated opinions will be appreciated….

 

[RJWEST]

Damage diff ? Don't know,

But why not get new tire to Match the spare tire, And use the 50% tire for the spare.

 

[BigPapa]

... will running the rear tires with this amount of difference in tread depth going to damage my rear differential?

No, it will not damage it.



Scott

 

[rbattelle]

Scott is probably right, but I don't blame you for being paranoid. I would be.

If it were me, I'd put the new tire up front and keep it there for awhile (which will screw up your rotation pattern a little) until it gets some wear on it.

Ryan

 

[HBarlow]

In theory you are correct to be concerned because the difference in tire diameter between one new tire and one partially used tire will cause a slight difference in rotation speed between the rear wheels which will keep the spider gears in the differential operating 100% of the time. However, I'd guess the speed differential would be slight and unlikely to cause any harm. It would probably be about like driving continuously around a long circle track.

I would probably do the same thing Ryan suggested above. Use the mismatched tires on the front or buy one new tire and pair it with the spare and put the used tire on the spare wheel as RJWest suggested.

 

[MMerlino]

Thanks to all who replied. I does make you feel better to get various opinions from other involved CTD owners. At the first opportunity I believe I will rotate the tires which will put the new one on the front axel.



MM

 

[cojhl2]

Firstly, I don't rotate tires and always replace in pairs regardless. .



I probably won't get much agreement on that philosophy will I?



Anyway, although the tires ask for 80psi thats way too much unless you load the pickup enough to put the tires within their rated load range.





What I have found over the years is that on the front because of the heavy engine the psi is correct. But,,, on the rear I run about 50 unless I know I'm gonna be loaded.



Before I did that I could only get about 40k on the rear tires as they were wearing in the middle of the thread only.