Problems running 1 new tire in 4WD??

Hey guys, long story short I bought 5 BFG AT's, 4 used with 60% tread, 1 brand new all 265/75/16.

One of the used ones has a big gash in it and can't be used. I'm having the 3 used tires + 1 new tire installed on the truck as we speak. The difference in tread is 7/16". I'm wondering if I'll run into any driveline problems running the new tire with the 3 used ones. The new tire is going in the rear drivers side to combat some rear Taco lean I have.

Anybody see any problems with this setup? Especially in 4WD? I only use it on dirt/low traction surfaces to allow for some slippage.

 

I'd put the new tire up front. Otherwise, your rear wheels will never run the same speed side-to-side with different circumference tires, causing a potential differential wear issue. The front won't matter if the wheels spin at a different speed with the ADD. Though it may F up your VSC.

As far as 4wd goes, you will be on slippery stuff anyway. No worries.

 

you wont have any problems..my neighbor is so cheap he buys one tire at a time..always. three bald ones, one new one. he judges tire life by it's ability to stay inflated, not tread wear.

unlike what the subaru tech told me for our subaru.

 

major problem. this will throw your system off big time. I used to work for Goodyear (HQ) and we would see people try this and cause big problems. The tires need to be with 2/32nds of each other

http://auto.howstuffworks.com/replacing-tires.htm

 

Full-time AWD is a different story. Which is why afficianado was told to replace all four tires on his Subaru. We are talking about part-time 4WD.

 

bash42 is absolutely correct, and 2/32nds is factual. However, that applies much much more to AWD, and GP3's advice is applicable in this scenario. At the end of the day, if the tire is on the front and you aren't driving around the streets in 4WD, you'll be just fine.

 

seriously?

some cars even have staggered tire sizes. i dont get it.

 

those cars are designed that way and they dont have a system in which all four wheels are locked to each other. derp

 

bash is right, it can create major problems(blown transmissions) on AWD cars. Any AWD vehicle with staggered tires, you'll find the tires are the same overall circumference. Jeep SRT8 is a perfect example.

 

Looks like I'll be swapping to the front when I get home then!

I knew about the AWD issue, and the tire tech even said the same about Subaru's. He also mentioned that some Subaru guys go to the dealership and get their new tires shaved down to match the used ones.

Any idea where I can get this done? Or should I just swap to the front and call it a day?

 

just get a second new tire. Its not a good idea two have differnt curcumference tires on the same axle.

Both wheels will rotate the same # of times, but the one with the new tire on it will travel farther than then used tire. The geometry doesnt work out in your favor.

Not really worth the risk IMHO....

 

Agreed that it's not a good idea to have 2 different circumference tires on the same DRIVE axle. On his front axle, it won't matter unless he's in 4wd on pavement. If he's only using 4wd in very slippery conditions, then it won't matter.

 

But if it's in the front, where is the problem? The front axles aren't ever engaged on the street, only in loose dirt/snow/mud. I really don't have $200 for a new BFG AT, considering I just bought the 5 of these for $245.

The places I wheel rarely ever call for 4WD, so even when I'm wheeling I'm usually in derprunner mode.

 

On 05+ your front axles are always engaged. They are connected directly to your wheel hub/bearing. Whic is connected directly through your axle shafts to your differential.

1. Your differential is working a little overtime.
2. You're allowed up to 3% difference in overall tire diameter. Not sure if that applies to toyotas, that's a general spec for the transfer case.

 

If what you say is true, and these tires are 31" in diameter brand new, then 3% of that is .93". 7/16" is a little over .5", meaning I'm technically within spec, correct?

 

Did the math to figure out the difference in circumference.

Per revolution:
New tires - 97.3 inches
Used tires - 95.8 inches

Difference of 1.5" rolling distance per revolution. I can't see 1.5" being a big deal if it's on the front. Am I wrong here?

 

It's the difference between the tires new and old.

 

the law of scale makes it a problem after all your miles.

I just did the math, and every mile you drive, your used tires will rotate roughly 661.38 times and the new tire will rotate 651.18 times.

Now that 10 rotation difference and take it out through an oil change (5,000 miles) and the one side of your vehicle has tried to rotate its tire 50,000 more times that the other side.

See any issues now?

 

Only one side IIRC.

Not directed at you Jamie:

Essentially on a rear axle your spiders, inside the carrier, which don't normall have to spin -- except through turns, are now spinning constantly, this causes wear, you'll shorten the life of your 3rd. By how much? Hard to say. Is it really that much of a concern? Probably not. You see lots of older rigs with mismatched tires on stock gears. I'd run it on the front and call it a day (I'd be hesitant on the rear though with that much difference), and like I said, I believe only one cv axle is permanently connected.

Oh and naturally... don't use 4wd anytime your tires can't slip.

 

I would just get 2 new and then have the other one in storage in case it's needed.