Tire belts going bad

[idM1028]

I keep having problems with tire belts going bad in my M1028. It's always the the drivers side rear tire and I always know when its going bad because the truck will start wobbling from side to side at low speeds and will start shaking badly at about 45-50 mph, which with the speedo the way it is is probably about 40-45 mph. After that it smooths out a bit. The truck originally had 235/85/16 load range E cooper discoverer A/Ts. I run the tires at about 70-75PSI. The truck started having this problem when I first bought it. I did some searching and figured the problem was bad belts and replaced the tire with the spare (a cooper discoverer also 235/85/16 load range E) The truck ran fine for about 500-100 miles until this started again. When I swapped out the tire I jacked the truck up and noticed the rear diff was at angle with the passenger side sitting lower than the driver side, but when I lowered the truck and measured the height of vairous things, they where all within a 1/4" to 1/2" of each other between the two sides. I also trying yanking on the tire to see how much play was in it to see if it was a bad bearing and it seemed to be fine. I also haven't been hearing any squeaking like I would expect with a bad bearing. My question is what could be causing these tires to constantly be going bad?

 

[jbingvtx]

If they are the original for the truck they could be very old.

 

[idM1028]

First thing I did when I noticed it today was take it to the Firestone on the way home. The guy I bought the truck from said the tires were put on a year ago or so, but they were bought as surplus. The mechanic at the Firestone said the spare that's bad is 7 years old and the one on the other side is 17 years old! I'm wondering why I'm not having any problems with all the other tires (which are probably 17 years old) and keep having problems with just this one! Something's gotta give. . .

 

[bevanet]

Is the rim bent?

 

[jbingvtx]

With tires that old problems could be right around the corner...or years away, impossible to tell. Typically 235/85R16's are 10 ply [load range E] so its not common to have a pothole shift belts. If you determine that it is definately a tire problem I would say its due to age or perhaps abuse by a previous owner. I would not try to replace them with more surplus tires, this size is available at almost any tire shop.

 

[idM1028]

@Bevanet: Thought of that. Haven't had them checked yet, but it's definitely a possibility. Might not be a good idea, but I could definitely swap tires and wheels around and see if the problem continues.
I'm not sure at this point whether I should replace my tires or just wait for my new wheels and 35's. Apparently, the tires are still under warranty so I'll see if I can get a new set (definitely not surplus this time). If that doesn't work I'm thinking about getting a set of say, BFG T/A KO's in the stock size as they can be had for a decent price and are supposedly good tires for the price. Once I get the new wheels and tires I can always sell them. Either way, I'm hoping I can figure the problem out before I slap a $1,000 set of 35's on the truck.

 

[rickf]

Under warranty at 17 years old!!!!! My guess would be that the tires were run with a heavy load and then cross rotated. That could make the belts shift in some of the older radials. I would lose the 17 year old tires fast, The rubber compound is probably hard as a rock and if you have to stop fast it will be like wet ice.

Rick

 

[idM1028]

Supposedly the guy the tires were bought from was willing to warranty them. I really don't run the truck with a heavy load. The truck originally had troop seats (since removed) and all I keep in the bed is odds and ends I really don't care about having stolen (nothing that heavy. Probably not even 50 lbs total weight) The tires had been on the truck for about a year before I bought it. I haven't had problems with any of the other tires, just the two I have put on in the same exact spot. I haven't even put enough miles on the truck to justify rotating the tires. Like I said before, I seriously suspect there is a problem with the truck. If there is I'd like to fix it before burning up more money on messed up tires.

 

[rickf]

75 lbs. of air seems to be a lot for an empty truck. I run 45 in the rears and 55 in the fronts on mine and still tend to wear the centers out on the back.

 

[acmunro]

I would get rid of those old coopers as soon as possible. I have had the entire cap come off one on my truck. Tire looked great but was older than 5 yrs. It was not a recap. The whole tread just came off. Tire didn't deflate so I limped it about a mile until I could get a safe place to change it. Since then I have been down on old tires.

 

[motomacguyver]

I would start by having someone knowledgable follow you to see if it's "dogtracking" Then get a four wheel alignment done. A two wheel alignment won't show rear axel crookedness.

 

[idM1028]

@ Rick. Thanks for the info. 70-75 seemed a little high to me too.
People who have followed behind me have already said they can see wheel and tire bouncing. When I had the problem the first time I took it into Firestone and had the alignment done. Not sure if they did the front or both. I'll have to find the paperwork. I saw it the other day. It's floating around here somewhere. Either way, I have lifetime alignments on the truck.

 

[Barrman]

They did a 4 wheel alignment. All Firestone stores use Hunter equipment and it automatically does a 4 wheel. However, since it is a solid axle truck. I bet the guy doing the work didn't even look at the rear axle data. If you go back. Tell them you want to know what your thrust line is and if possible, to align it with the centerline. The machine can do it if the tech know how to work the machine correctly.

Buy 4 new tires. That is the simple and really only safe answer. I know it cost a bunch. My 1009 had some old tires on it. I kept it below 60 mph as my self imposed red line until I could buy a new set on there because I didn't want to hurt myself or others. Normally, I kept it around 50. My tires had no wobble or out of round issues. Be safe and smart. Get new tires.

 

[idM1028]

@Barrman thanks for the info. I didn't exactly think it was a good thing when I took it in there the first time and the only person who knew how to align the thing was the old codger that was working there.
I'm starting to think a new set of tires and realignment is in order. Granted, not cheap, but certainly more bearable than killing myself or God forbid, someone else on the road. And since this entire thing is bumming me out, to keep things on the lighter side, a snippit from a converstation I had with my buddy last night concerning the problem:
Him: I really don't know what to tell you.
Me: C'mon. You've got to tell me something! And don't tell me it's a magical unicorn thats causing it. . .
Him: Naw, it's a leprechaun. Unicorns only mess with the passenger side.