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Replacing 1 tire/Tread Depth. Lets fight.

ShadowsPapa

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Me - 5 new A/T tires, 5 tire rotation (I have matching wheel) and will rotate often enough to keep them all similar size.
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BamaJeepTruck

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This is all wrong. If you damage a tire beyond repair on a trail, you must increase the size of all tires by at least 5% to prevent such damage from occurring again. This is the way.
LOL, if that was the case I would be very happy. We'd be selling a lot more that way!
 

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I'm not a mechanic, just a guy that likes to critically think. Tell me where my thinking is incorrect.

If you damage a tire on the trail, can you replace just the damaged tire?

My contention is yes, as long as your vehicle isn't fulltime 4wd or AWD.
The wheels spin independently unless you have the diff locked. Since they spin independently, there is ZERO more stress on the diff than if you were driving on a curvy road. There is zero more stress than if one of your tires was running 5 lbs less than another. Running 3 tires at 9/32nds and 1 tire at 16/32nds wouldn't make a damn bit of difference or damage in my mind.

Tell me why I'm wrong. Not what the tire salesman says, but how exactly running the 2 different tread depths of the same tire causes damage to the drive train with an open diff. And before we start talking about running it in 4wd, remember we shouldn't be running in 4wd until the surface conditions are loose or slick, once again, creating a condition where the diff wouldn't bind.

I'm really asking this question to learn. Tell me the why, not the recommendation of the tire place.
This is correct, because you put the caveat of not running in 4WD or having an AWD system.

Even with 4WD/AWD, you can run different size tire for a short period of time.
 

LostWoods

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This is what brought up the question. I'm not doing 5 tires, never have, not even on a wrangler. Over the life of the vehicle, (say 175-200k miles) I see no benefit in 5. you rotate 5, you replace 5. I've had no issue throwing my spare on when needed and either using it or getting a replacement for a damaged tire without replacing all 4 tires.
I guess the question from me is why buy 5 if you don't intend to use it? Spares don't last forever and most manufacturers will recommend replacement at 6 years (significantly less here in the desert). Even sitting under a truck, they're exposed to heat and the elements that after a few years, they've dried out and will give a much shorter life if installed. The number of spares we replaced on trucks with 95% of their tread left was always staggering to me.

I just don't see any valid argument against a 5-tire rotation if you have 5 to rotate.
 

AmishMike

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'I just don't see any valid argument against a 5-tire rotation if you have 5 to rotate.'

Time and effort.

Not that I am necessarily lazy, but I work 70+ hours a week. My Jeep is part of my life, it is not my life. My spare time goes to my family.
 

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ShadowsPapa

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This is correct, because you put the caveat of not running in 4WD or having an AWD system.

Even with 4WD/AWD, you can run different size tire for a short period of time.
Well, let me toss this in the mix - my wife hit debris that was close to the edge of the tread. No tire shop wanted to touch it. I talked one shop into doing the repair with the stipulation that we'd run the spare on her Jeep and use the repaired tire as spare. Yeah, difference in wear and miles because the spare had never been on the ground. It was a Grand Cherokee.
A lot depends on the systems, but in any case, we're talking almost no difference in rotation speed.
If tires always wore perfectly evenly, you'd not need to rotate 'em to even out the wear. There's always going to be some differences. I'd not be afraid of, say, swapping in a new spare on a vehicle with 20K miles on the other tires.
Again, do the math. Figure a tire diameter of exactly

Two tires with .2" difference in diameter - that means 1/10" wear more than the other tire
103.67 611.17 rotations per mile
104.3 607.47 rotations per mile
3.6 rotations per mile difference.
You have more differences in rotations just driving down the highway unless it's a Nebraska highway with no curves what-so-ever.
Seriously, drive through parts of the country where nothing is straight and you have a bigger difference in 1/4 mile.


I guess the question from me is why buy 5 if you don't intend to use it? Spares don't last forever and most manufacturers will recommend replacement at 6 years (significantly less here in the desert). Even sitting under a truck, they're exposed to heat and the elements that after a few years, they've dried out and will give a much shorter life if installed. The number of spares we replaced on trucks with 95% of their tread left was always staggering to me.

I just don't see any valid argument against a 5-tire rotation if you have 5 to rotate.
Most shops around here won't even touch a tire that's 7 years old. They won't even break one down or air one up. They look at the date code and if it's 7 years or older they tell you to get it back out of there.
 

smw17gladiator

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Me - 5 new A/T tires, 5 tire rotation (I have matching wheel) and will rotate often enough to keep them all similar size.
So I’m going to do 5 tire rotation on my JT as well (35 ATs). Primarily for peace of mind that if I need the spare it hasn’t been sitting idle under the truck for who knows how long. Pulled out some spares from past trucks that may not have been actually dry rotted, but we’re at least well on their way. Just curious as to your thoughts on the “often enough” gauge for rotation to keep treads similar among 5. Also, thinking I need a 5th TPMS in tire that started out as spare - presume no issues with truck picking up which TPMS are on mounted tires after rotation versus one that got rotated into spare? Thanks, and apologies for any questions that should be obvious.
 

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I'm not a mechanic, just a guy that likes to critically think. Tell me where my thinking is incorrect.

If you damage a tire on the trail, can you replace just the damaged tire?

My contention is yes, as long as your vehicle isn't fulltime 4wd or AWD.
The wheels spin independently unless you have the diff locked. Since they spin independently, there is ZERO more stress on the diff than if you were driving on a curvy road. There is zero more stress than if one of your tires was running 5 lbs less than another. Running 3 tires at 9/32nds and 1 tire at 16/32nds wouldn't make a damn bit of difference or damage in my mind.

Tell me why I'm wrong. Not what the tire salesman says, but how exactly running the 2 different tread depths of the same tire causes damage to the drive train with an open diff. And before we start talking about running it in 4wd, remember we shouldn't be running in 4wd until the surface conditions are loose or slick, once again, creating a condition where the diff wouldn't bind.

I'm really asking this question to learn. Tell me the why, not the recommendation of the tire place.
If your Jeep doesn't have have full time 4wd option, just put the new tire on the front and call it a day.
 

Ankh

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I'm not a mechanic, just a guy that likes to critically think. Tell me where my thinking is incorrect.

If you damage a tire on the trail, can you replace just the damaged tire?

My contention is yes, as long as your vehicle isn't fulltime 4wd or AWD.
The wheels spin independently unless you have the diff locked. Since they spin independently, there is ZERO more stress on the diff than if you were driving on a curvy road. There is zero more stress than if one of your tires was running 5 lbs less than another. Running 3 tires at 9/32nds and 1 tire at 16/32nds wouldn't make a damn bit of difference or damage in my mind.

Tell me why I'm wrong. Not what the tire salesman says, but how exactly running the 2 different tread depths of the same tire causes damage to the drive train with an open diff. And before we start talking about running it in 4wd, remember we shouldn't be running in 4wd until the surface conditions are loose or slick, once again, creating a condition where the diff wouldn't bind.

I'm really asking this question to learn. Tell me the why, not the recommendation of the tire place.
No tire input here, but great screen name.
 

wchevron

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Is it going to break your truck, no. Avoiding catastrophe shouldn't be your only goal tho. The truck will be better off on matching tires. At least replace them in pairs, and the new ALWAYS go on the front axle.
Why on the front axle vs the rear?
 

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ShadowsPapa

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So I’m going to do 5 tire rotation on my JT as well (35 ATs). Primarily for peace of mind that if I need the spare it hasn’t been sitting idle under the truck for who knows how long. Pulled out some spares from past trucks that may not have been actually dry rotted, but we’re at least well on their way. Just curious as to your thoughts on the “often enough” gauge for rotation to keep treads similar among 5. Also, thinking I need a 5th TPMS in tire that started out as spare - presume no issues with truck picking up which TPMS are on mounted tires after rotation versus one that got rotated into spare? Thanks, and apologies for any questions that should be obvious.
It will pick up the TPMS on the 4 corners and ignore the spare until you swap, then it will pick up what WAS the spare and ignore the other.
I have identical rims, identical TPMS and identical tires and my truck picks up whatever is on the ground.
I've even swapped wheels and tires for winter vs. better weather driving and it just automatically picks up the TPMS on the 4 corners of the truck and ignores anything else.
 

ShadowsPapa

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Here's one that will toss another angle into the tire wear/size discussion.
TPMS.
The Jeep vehicles so far use physical sensors in the rims that literally sense the pressure. That's called direct TPMS.
What about vehicles that do it virtually with no sensors in the wheels - the first generation of indirect TPMS go by the differences in WHEEL ROTATIONAL SPEED. Indirect TPMS.

The current generation can sense under-inflation in all wheels as it doesn't have to compare rotational speed among the 4 but that's a different topic.

My take is that if you have a vehicle with first generation iTPMS you need to keep the tires pretty well identical.
 

BamaJeepTruck

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Why on the front axle vs the rear?
The front axle is the steer axle, in a decreased grip scenario you want to be able to steer out of the slide. Having new tires on the rear just ensures the vehicle can accelerate as locking up the brakes will just increase the slide. no matter front or rear drive you always want the better tires on the front. Michelin did extensive testing on this in the mid 2000's.
 

ShadowsPapa

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The front axle is the steer axle, in a decreased grip scenario you want to be able to steer out of the slide. Having new tires on the rear just ensures the vehicle can accelerate as locking up the brakes will just increase the slide. no matter front or rear drive you always want the better tires on the front. Michelin did extensive testing on this in the mid 2000's.
And in a front wheel drive vehicle, even 4 wheel drive you can pull out of the skid. Better to pull across something slick than push across it.
Michelin testing was second to none, IMO.
Glad my wife has their tires on her WK2.
 

OldButStillJeeping

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I type this respectfully... But...

You guys are actually discussing less than 2/10ths of tire tread difference in relation to AWD and 4WD performance?

This is a bit over the top. Respectfully, do ya'll have A Life? A spouse? Something else to do?

There are mental health clinics available! LoL.

Hell, take your top and doors off of your JT and take a drive! Live life!

Live life to it's fullest. And frankly, it isn't found online.

See you on the trail... If I don't see you coming first. LoL.

(Meant in jest. Or was it)
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