Different tread depths on same axle

[blkfordsedan]

I'm in the process of installing some different tires & rims on my F250 (2WD). I got (4) used P255/70R-16 General Grabber AW tires for free.
3 of them have about .200" (50%) of tread depth and the fourth is bald. I bought a matching tire at a used tire place that has about .350" (95%) of tread left.

Do you guys think if I put the newer tire on the right rear (for traction) it will hurt the differential or cause excessive wear on the spider gears?
I did the math, and at 60MPH we're talking a difference of about 6.5 RPM, which is about 1 revolution every 9 seconds. Is that enough to hurt it?

My only options are to put it on the front :sad:
OR........................
Put it on the right rear and do burnouts until it matches the others :iconbiggrin:

[Festy46]

I wouldn't worry about it. Take your finger and make a small circle on your desk, but take 9 seconds to do it. Now imagine that circle being done in an oil filled environment. You're not going to hurt the spider gears.

[crazyrog17]

I like that, Festy46. Good example.

[schads]

i agree that it will not hurt anytning at all.

[Safety Guy]

Do a few burnouts to even it out a bit anyway.

Good excuse for them, eh?

Karl

[drddan]

The rear gears have "slip". Otherwise you would not be able to turn a corner without "chirping", the outside tire on a turn. Not to worry at all. You could run 15 inch on one side and 16 inch opposite side and it still be ok.

[blkfordsedan]

I pretty much agree with all of you, I just wanted to run it by everyone to see what you thought. It is an "open" differential (critical info I left out), so it shouldn't be an issue. Basically, thats what happens anyway when you spin one wheel on ice or doing a burnout, except at a much slower rate. If anything, the better tire on the RH side will get more traction than the other side and help split the power more evenly. I used to be able to get an open differential to burn both rears like a posi just by installing old school traction bars and adjusting the RH side closer to the leaf spring than the LH side.

[Festiva Time]

You want to run even tires up front in case you brake real hard. I would put the "newer" tire on the Left rear. No real good explaination for it.

-Kirk

[batstiva]

Don't know what year F-250 you are talking about, but I feel pretty confident you will not damage anything by having one rear tire with slightly better tread. I've had two F-250s, an 89 and a 91, and I'm pretty sure if all the hell I put those things through didn't destroy the rear end, slightly different tire sizes are not going to cause you any problems.

[blkfordsedan]

Don't know what year F-250 you are talking about, but I feel pretty confident you will not damage anything by having one rear tire with slightly better tread. I've had two F-250s, an 89 and a 91, and I'm pretty sure if all the hell I put those things through didn't destroy the rear end, slightly different tire sizes are not going to cause you any problems.

It's a '97 F250HD, but the rear axles are pretty much all the same. Mine has the bigger full floating one since it is rated over 8600GVW. As long as I don't have a Traction-Loc (which I don't) I don't think its a big deal.
Sometimes I over-think things....then I get paranoid. Lord knows I've owned plenty of cars with 3 near-new tires and 1 completely bald tire on the Right rear!