Tire replacement

[blakshukvw]

Hahaha. I run 9” wide front wheels with 255/45’s and 10.5” rears with 275/40’s on AWD 5.0 2nd gen. These tires measure within 1.5% of each other. No issues with the T case. They’re not as sensitive as everyone believes.

 

[Mbrooks420]

1.5% is extremely close.

 

[blakshukvw]

1.5% is extremely close.

Yep. One would be hard pressed to have 1 worn tire be out that much more than the rest. Even buying used tires, if the wear looks close, id say there’d no issue.

 

[XLTrunner]

1.5% difference seems minimal until you consider that on a typical 30" dia. tire for these vehicles, that's just shy of 1/2". With that said, I've also read where AWD is a little more tolerant to slightly different sized tires than the Control Trac systems. To confuse the argument even further, the claimed accelerated wear on the transfer case isn't going to make itself known for who knows how many miles...and, then will often be dismissed as being caused by other factors. I've been thru one expensive transfer case rebuild and prefer to follow Ford's recommended guidelines for running matched tires to help prevent a re-occurrence.

 

[Mbrooks420]

1.5% difference seems minimal until you consider that on a typical 30" dia. tire for these vehicles, that's just shy of 1/2". With that said, I've also read where AWD is a little more tolerant to slightly different sized tires than the Control Trac systems. To confuse the argument even further, the claimed accelerated wear on the transfer case isn't going to make itself known for who knows how many miles...and, then will often be dismissed as being caused by other factors. I've been thru one expensive transfer case rebuild and prefer to follow Ford's recommended guidelines for running matched tires to help prevent a re-occurrence.

The ControlTrac would be less picky than the 4404, which is in 4wd 100% of the time and any difference will cause a degree of sheer and heat buildup inside the viscous coupling. The 4405 has a small amount of slippage that gets completely ignored so the t case isn’t going into 4wd every time you turn the wheels.

Also, with the 4405 you could do a brown wire mod and run 29s up front and 35s in the rear and the transfer case would be completely fine.

 

[J_C]

^ What's the T-case clutch clearance? I'd wonder if significantly different speed, shears or heats the fluid more, would want to keep an eye on that.

 

[blakshukvw]

1.5% difference seems minimal until you consider that on a typical 30" dia. tire for these vehicles, that's just shy of 1/2". With that said, I've also read where AWD is a little more tolerant to slightly different sized tires than the Control Trac systems. To confuse the argument even further, the claimed accelerated wear on the transfer case isn't going to make itself known for who knows how many miles...and, then will often be dismissed as being caused by other factors. I've been thru one expensive transfer case rebuild and prefer to follow Ford's recommended guidelines for running matched tires to help prevent a re-occurrence.

Mine are 26” tall tires. 1/2” doesn’t even bother me. Uneven tire wear from stock camber settings can create that kind of wear difference. Audi older awd systems were similar to the awd in the X and the acceptable range for staggered tires front to rear was 3%. I’m not worried.

 

[J_C]

^ Worried is subjective. Objective is that it puts more wear on drivetrain. The real question is why even chance it if it is not expensive to not have to gamble on the outcome?

Plus, bad camber settings causing an extra 1/2" wear does not seem like a way to state everything A-okay but rather, you have two things to fix now.

Plus, if the mismatch is on the front axles, I can feel the degraded handling on vehicles, and these are not especially good handling to being with.

I'm not suggesting they have to be exactly the same, only that it is worth trying to get them as close as possible, because this is obtainable by shopping around for used or shaving a tire, a sub-$50 extra expense rather than several hundred to replace all 4.

 

[blakshukvw]

^ Worried is subjective. Objective is that it puts more wear on drivetrain. The real question is why even chance it if it is not expensive to not have to gamble on the outcome?

Plus, bad camber settings causing an extra 1/2" wear does not seem like a way to state everything A-okay but rather, you have two things to fix now.

Plus, if the mismatch is on the front axles, I can feel the degraded handling on vehicles, and these are not especially good handling to being with.

I'm not suggesting they have to be exactly the same, only that it is worth trying to get them as close as possible, because this is obtainable by shopping around for used or shaving a tire, a sub-$50 extra expense rather than several hundred to replace all 4.

I was willing to do it because I wanted a certain look. I spent the time researching tires to find a pair that were the closest in size with a staggered look.
I didn’t say “bad camber settings”. I said stock camber settings. Stock camber is pretty wide range and goes over -1degree. That’s enough to wear tires uneven enough to equal 1.5% that I have on my staggered setup.
Theres no degredation in handling, trust me, I went from stock 15’s that are what, 185mm wide to 255mm in front. The truck handles much better being lowered and with uhp summer only tires even with the staggered setup.

 

[J_C]

^ Have to disagree, I've never had my tires wear to 1/2" difference on my '98. It seems most likely that when yours was lowered, it was not correctly aligned.

Stock 15" wheels had at least 225/70 or more often 235/75, then 255/70 on 16".

I'm talking about degraded handling from 1 tire being different on the front *axle*, a difference between left and right front tires, not difference between front and rear, since the topic is about replacing one tire.

 

[blakshukvw]

^ Have to disagree, I've never had my tires wear to 1/2" difference on my '98. It seems most likely that when yours was lowered, it was not correctly aligned.

Stock 15" wheels had at least 225/70 or more often 235/75, then 255/70 on 16".

I'm talking about degraded handling from 1 tire being different on the front *axle*, a difference between left and right front tires, not difference between front and rear, since the topic is about replacing one tire.

My stock tires had bad camber wear that amounted to at least a half inch wear difference between front and rear. That’s how wide the window for acceptable camber is stock. I aligned my x when I lowered it. It’s aligned fine.