Question for tire people

[gbm85]

I just got two tires replaced on my truck because the front ones had shoulder wear (sign of under-inflation, even though I always keep them at 40). They did appear a little flat though, even when fully inflated.

Well, I had my old rear tires (which were perfectly fine on the rear) moved to the front and had the new tires put in the rear. Well, now these same tires, which were just peachy on the rear, are showing the same "flatness" even though the inflation level is exactly the same.

So my question is, what makes my tires look flat when they are on the front wheels? Is it the extra weight of the engine? Is it improper camber? Am I going to get shoulder wear on them even though they are technically properly inflated?

Any help is appreciated

[Evil Queen]

My first thought is "tubeless" tires but since you moved the old tires to the front, I don't know. Do the new tires still look like they're flat?

Could be you got a heavier front the rear? Of course, that makes no sense...

[wagegoth]

Could be you got a heavier front the rear? Of course, that makes no sense...

Since it's a truck, actually, it does. An empty truck is going to have most of its weight on the front.



gbm85, Is it wearing on both edges of the tire, or just one? If it's one, then the camber is off. If it's both, you should talk to the tire store. If they can't help you, contact the manufacturer. They may have special recommendations for inflation based on load and location on the vehicle.

[crazylegs]

Check your tracking (alignment), check your owners manual and make sure that your front wheels are inflated correctly, on my little skoda fabia with a tiny 1.4 engine I have to have the front wheel inflated to a higher pressure than the rear so on a truck it most certainly will be true too.

[gbm85]

Thanks all. I will check the recommended pressure. Though I'm pretty sure it will be less than 40. The tires are 44 max, but I don't want to risk blowing out if I hit a pothole, not to mention the ride would be less comfortable.

wagegoth, both edges of both tires were worn. I'm going to get the alignment checked anyway, just to be sure.

I'll probably just have to start rotating the tires regularly. I've only had the truck for about 2 years, and I never really did much to it besides changing the oil, mostly because I expected to have a new car by now. The new tires are rated at 85,000 miles, and even if I only get 50k, they'll probably outlast the truck itself.

[protege]

If both edges of the tire are worn, it's under-inflated. What happens, is that the rim's raised edges puts more pressure on the edges, causing them to wear. Check your tire pressures. If they keep going low, it sounds like either the air stem (valve) is failing, or you've got something stuck in the tread.

[It's me]

For the inflation pressures... the recommended pressure will be on a sticker on the door jam or in the glovebox (usually, might be elsewhere). The recommended pressure will also be in the manual... for a truck the manual is the better place to look as it will usually list tire pressure to use with different cargo weights.

Also, the pressure on the sidewall of the tire is the _maximum_ pressure that can be used with that tire... as noted above the pressure that should actually be used can be found in the info provided by the manufacturer.

[Lachrymose]

Tire people?

You mean like the Michelin Man?

[Dips]

You might also want to be sure that the guage you use is accurate. If it's off by a few pounds then your tires may be underinflated without your realizing it.

[digilight]

First thought would be Allignment as well (Toe, Camber, and Caster) Check this page http://www.familycar.com/alignment.htm for more info. I would almost bet that your problem is possibly Toe-in as well as Camber resulting in both sides wearing poorly and quickly. The bad news is that if the front tires are that bad off now, you will need to replace them after you get the problem fixed. Otherwise you won't have enough tire making contact with the road.

[wagegoth]

wagegoth, both edges of both tires were worn. I'm going to get the alignment checked anyway, just to be sure.

Definitely, then, the tires are underinflated. Alignment issues would cause uneven wear on one side or an unusual uneven wear pattern to the tread, depending on the severity of the issue.

Having them underinflated can actually make for a poor ride and a more dangerous one. If you check the pressure while the tires are cold, then you should fill them a couple of pounds under maximum. If, however, the tires are warm, then they can be filled up fully. Underinflation obviously causes uneven wear on the tires and can affect handling and shorten the life of the tires.

I had a Corrado at one time with Yokos that were filled to 44. I actually had a guy at the gas station let air out of them because he thought they should be lower (he was sweet, but mentally not fully developed). As soon as I pulled away from the island, I could feel the handling was wrong. I drove back in and filled them up and things were back to normal.

[BookstoreEscapee]

I read this title as "Question for tired people" and thought now there's a thread for me! Oh well...

carry on

[dalesys]

We're really good at carrying on, too.