I bought a 2002 Suburban and the previous owner replaced two tires at time with the same make and size. When the two front tires wore out after I purchased it, I put two great condition used tires on of the same size but different make because I plan on putting four new tires on in the spring. When I put the vehicle in four wheel drive for the first time this year, the front end made a dull but noticeable whine. I took it to a shop and the mechanic tells me everything is fine mechanically, the whine is due to the tires being different size. He says the circumference is smaller on the tires I put on even though they are the same size tires as the rear. He also tells me this is a big transfer case concern because the front end is turning faster than the rear.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
<o:p> </o:p>
I might be old school but the vehicle will only be in four wheel drive when traction becomes a problem. I those situations, the tires can slip or spin easily as compared to dry pavement. The way I see it, most of the wear should be on the tires. I only put 5000 miles on the vehicle annually so I might be putting on a couple thousand miles before the new tires.<o:p></o:p>
<o:p> </o:p>
How much variation in tire size exists between different tire makes? If so, why? Are there no standards held to the tire makers?<o:p></o:p>
<o:p> </o:p>
How much tire size variation is acceptable front to rear on a four wheel drive before the drive train is compromised?<o:p></o:p>
<o:p> </o:p>
Am I really risking damage to the transfer case? Personally, I don’t think so but I would appreciate any feedback.<o:p></o:p>
<o:p> </o:p>
Thanks<o:p></o:p>

 

I'm with you, man. i recently had to replace front tires on the fly and i ended up only being able to find 265/70/16s instead of 265/75/16s so theres a 1.2" difference. I don't know what to do but my truck is a mile from home and im hoping i can get it home without stretching or destroying my tcase chain or removing my front driveshaft. its going to stay parked until i can get the right size. front shaft is also missing 7 of the 21 splines, but im unsure about which end of the shaft it is. Plus, im not really up for dropping a shaft in the parking lot of the gas station where it is. It is supposed to be out of their lot TODAY, so if anyone has any useful advise for me, please let me know ASAP. tires are being mounted as of now.

 

Tire sizes do vary from one manufacturer to another as well as different models of tires. If you are going to engage the 4wd it s imperative that the tires are the same size front and rear. If you don't use 4wd it wont matter.

 

I'm with MudManiac, if you don't use 4wd drive it doesn't matter, but if you have any doubts, pull the front driveshaft out, had to do that on my 78 due to different gear ratios in the diffs. i had use 4lo just to drive then slam it into to 2hi when i got up to speed.

 

naa.. hell leave the drive shaft in it. In 2WD it does not matter. No power goes to the front wheels. They are just there to keep the front bumper off the ground... lol

 

i had to pull it cuz the original 350 didnt have the power to move the truck, and i only had 2 and 3rd gear in the tranny.

 

It is true that on 4wd and Awd the tires need to be the same size all the way around, however there is not enough difference between manufactures (as long as all the numbers are the same) to cause a problem. Most of the time this does not cause a whine (which would come from damage to diffs or transfercase) unless there is 2 different sizes on the same axle. It usually will cause ABS and traction control problems. If you ABS light is not on then that is most likely not the cause of your problem.

 

it turns out it doesn't make any difference in 2wd, but in any case, 4x4 is still operational. but just to be safe, im going to pretend it doesn't have 4x4 unless im spinning and can't get traction, or unless i'm stuck. i certainly won't drive any distance in 4x4 until i resolve the size issue. tested the 4, didn't notice any noise other than vibration from the missing splines on my driveshaft, over the 1/2 mi. i had it engaged. better be safe than sorry. EMERGENCIES ONLY!