sensitive to tire size ?

[3bears]

I know AWD drive cars are and if you have two real worn tires they push you to get all 4.
My 4wd cheby truck when I switched to snows on the back, I just had to make sure that they were the same size, like not put on a 70 series snow tire and have 75 series on the other axel. ( learned the hard way, boy did that transfer case howl, but that was the tire shops fault they sold me the tires and then swapped them out to the matching size)
and our owners manual says to run the same size tires so Ive wondered about my spare which was a 245/70/16 running it with my 265/75/16's

so I just picked up a new (used) 5 star wheel and a new KO'2 for my spare same size as the rest 265/75/16 so now I will have no issue with my spare after my TBU

My current KO2's have about 15k on them. If I started doing 5 wheel rotations, would the truck not like the slight difference in tire diameter due to 15k wear on the others.

Cant imagine it would but wanted to check with you guys.

 

[JayRolla]

I know AWD drive cars are and if you have two real worn tires they push you to get all 4.
My 4wd cheby truck when I switched to snows on the back, I just had to make sure that they were the same size, like not put on a 70 series snow tire and have 75 series on the other axel. ( learned the hard way, boy did that transfer case howl, but that was the tire shops fault they sold me the tires and then swapped them out to the matching size)
and our owners manual says to run the same size tires so Ive wondered about my spare which was a 245/70/16 running it with my 265/75/16's

so I just picked up a new (used) 5 star wheel and a new KO'2 for my spare same size as the rest 265/75/16 so now I will have no issue with my spare after my TBU

My current KO2's have about 15k on them. If I started doing 5 wheel rotations, would the truck not like the slight difference in tire diameter due to 15k wear on the others.

Cant imagine it would but wanted to check with you guys.

If you have the always AWD transfer case its not recommended. My wifes Expedition is AWD and just one tire being a little low in PSI I could feel the drivetrain bind up when turning. Same with my AWD Turbo Talon.

But with just some wear on the tire you may be okay. If it was me I would just keep the tire new and rotate it in on the next set of tires.

 

[19963.4lsr5]

To me AWD anything should have a 5 wheel rotation so all tires are worn about the same.

The Qudra-Drive setup with the hydraulic varilocs in the front and rear diffs as well as one in the transfer case will start creating pressure with any difference in speed between the two item it is connected to (axles or driveshafts) and will burn up the stack of friction plates fairly quick.

Sent from my iPhone using Tapatalk

 

[JohnMc]

I'm not 100% sure on the different drivetrain options, but I don't think a 2000 SR5 would have an AWD mode, it would just be 2HI, 4HI, 4LO.

Tire diameter difference wouldn't make a difference in 2HI, and it would in 4HI or 4LO, but so would going around corners, you obviously can't use it on dry pavement. It wouldn't really matter much in any situation you'd normally be using 4WD.

With the multi-mode AWD transfer case, AFAIK there's no limited slip functionality in the middle diff on the 3rd gens (??? I think later model AWD modes had a Torsen LSD?) so even in AWD it wouldn't matter all that much, as you certainly wouldn't be locking that center diff.

 

[JayRolla]

I'm not 100% sure on the different drivetrain options, but I don't think a 2000 SR5 would have an AWD mode, it would just be 2HI, 4HI, 4LO.

Tire diameter difference wouldn't make a difference in 2HI, and it would in 4HI or 4LO, but so would going around corners, you obviously can't use it on dry pavement. It wouldn't really matter much in any situation you'd normally be using 4WD.

With the multi-mode AWD transfer case, AFAIK there's no limited slip functionality in the middle diff on the 3rd gens (??? I think later model AWD modes had a Torsen LSD?) so even in AWD it wouldn't matter all that much, as you certainly wouldn't be locking that center diff.

You can kill a rear diff on a RWD car if tires are different size as they are spinning at different speeds.

 

[JohnMc]

Maybe if it was a large size difference, and you did it for a *very* long time. It's accelerated wear, those spider gears aren't built to spin for millions of revolutions like the rest of the drivetrain is.

But on AWD cars that *do* have issues with even slight mismatches - it's like slipping the clutch or dragging the brakes non-stop. It's not a lubricated bearing being spun, it's a friction device that's just supposed to see occasional slippage being forced to slip constantly.

Sort of a difference between 'possible' and 'probable'.

 

[3bears]

thanks, Ill just keep it as a new spare and next time I buy a set I will start 5 wheel rotations. I don't want to burn anything up and I just swapped in an elocker