I have a 4WD diesel pick up with single rear wheels.
I need to replace two tires(one is a worn spare and one is a sliced tire).

So in replacing two new tires do they go on the back or the front? Online says to put them on the rear but the front is significantly heavier unless I have my camper on the back.

Comments appreciated.

According to Tire Review, new tires should always go in the back. Rear tires provide the vehicle stability, and if they have little tread, then stability is lost. Although new front tires will spread water and maintain traction, worn tires in the back will hydroplane and may cause the vehicle to spin out, says Tire Review. This is the same for vehicles with rear-, front- or all-wheel drive.

Tires with the best traction on the back. In your case we’ll assume the new tires will have the best traction.

From experience, when the rear tires let loose, the vehicle will pivot around the front tires if they still have grip. I got to experience this in Florida during the summer in a downpour. I kept slowing down, but the water got deeper and the rear just flipped around on me in an instant. I was going 50mph at the time in a pickup with no weight in the back. Going 50 forwards, then BAM! I was going 50 backwards.

If the front tires break loose first, assuming the vehicle is moving forward to begin with, the rear tires act like a drag chute and the front just keeps going in the same direction it was going when the tires lost traction.

Again from experience, front wheel drive, rear wheel drive, 4 wheel drive doesn’t matter; if the rears break loose while the fronts have grip, the vehicle will pivot around the front tires.

I learned the hard way that 4wd/all wheel dr vehicles need to have equal wear on the tires.
I had a pickup that I replaced 2 of the tires and the the 4wd would not disengage until I came to complete stop, put it park, & shut the motor off.
I took it to a pro drive train shop and the manager had the wheel/tires from his truck put on mine and had me test drive it and it worked fine. I went to Discount tire where I had bout the first 2 tires and had them match up by measuring the circumference and all was well.

When I was much younger my father always preached you put the best tires on the front because they were more critical in control of the vehicle. That was back when very few people owned 4wd vehicles.

Equal wear front and rear doesn’t matter on a 4 wheel drive Super Duty pickup. You should not be in 4wd unless you are on loose or slippery surfaces because the driveshafts are locked together. It’s in the manual. Rain on a paved road doesn’t count. The drive train will bind up otherwise. Mine binds up in 4wd on our gravel driveway in Michigan.

The reason you had trouble disengaging the 4wd was because your drivetrain was bound up. Happens to me at the boat ramp with new tires even. The solution is to pull forward a bit, shift to neutral, and let it roll backwards a bit which release the pressure on the drivetrain components allowing them switch back to 2nd.

All wheel drive is different and allows the driveshafts to turn at different speeds. Having different diameter tires messes with that and causes undue wear on the drivetrain.

Driving where? Summer & hot likely.

Right now my truck has 2 different size & types of tires, 4x4 Silverado. I have Blizzacks on the front, using them up. I will go into winter with matched 18” tires.

Not many use 4x4 on hot, dry pavement.

I would get 2 tires, matched to the type and size you want on all 4. I’m still a Michelin fanboy, I know they cost more.

Just a heads up. The spare tire is a different size than what was on the wheel tires. At least it was on my Superduty. My spare was an 18” tire and my wheel tires are 20”.

quote:

Originally posted by Lineman101:
Just a heads up. The spare tire is a different size than what was on the wheel tires. At least it was on my Superduty. My spare was an 18” tire and my wheel tires are 20”.

Yeah mine came like that also but a few years ago I bought a matching wheel and now have 5 tires that match. I did that when we went to AK on a 14,600 mile trip during covid...

new tires go in the front. steering is more important than traction.

quote:

Originally posted by smlsig:

quote:

Originally posted by Lineman101:
Just a heads up. The spare tire is a different size than what was on the wheel tires. At least it was on my Superduty. My spare was an 18” tire and my wheel tires are 20”.

Yeah mine came like that also but a few years ago I bought a matching wheel and now have 5 tires that match. I did that when we went to AK on a 14,600 mile trip during covid...

That answers my first questions of DRW or SRW
I'd agree with others, put them on the rear.

quote:

Originally posted by hrcjon:
new tires go in the front. steering is more important than traction.

Not unless you are the best backwards driver ever. What tire loses grip in a high side crash? How many vehicles have the bigger wider tire/tires in the front? Why is that? Imagine driving an 80s 911 Turbo with the wider tires on the front.

The correct and only answer is that two new tires ALWAYS go on the back. If someone tells you otherwise, they are incorrect.

The tire industry has studied and tested this, spending perhaps millions of dollars in testing, and they all agree that new tires always go on the back. It is now an industry best practice. It saves lives.

Back in the day I used to put new tires in the front, before I knew better, and I have personally spun out on the highway just like the other guy in this thread did.

You can still brake and steer with half worn tires on the front. But if you lose traction in the rear, you are spinning and wrecking.

Also, I have been on a wet pad and tested this and its almost impossible to outdrive the rear tires and cause a spin if the rear tires are new. If the front tires are new, you can easily, and I mean easily, cause the car to spin out.

Here is a tirerack article on the subject:
https://www.tirerack.com/upgra...fferent-tread-depths