2nd Gen Non-Engine/Transmission tire flat spotting

[FourBarR]

I have owned this truck for 14 years from new. Use michilin tires . Truck is driven every day so no sitting. Tire pressures checked every 2 weeks to factory pressures 50 psi front and 60 rear with no load.

recently did the front brakes a job I have done many times. This time new rotors,overhauled calipers,all new wheel bearings (timkin) New brake linings,and new brake hoses. Wheel brgs packed with high temp grease. Bearings tightened up spun wheel loosened ,spun wheel ,tightened final adjusted so no play .

Dont know why flat spotting happened ,anyone any ideas?

 

[mwilson]

Can you attach a few pictures so that we can see the wear pattern??? That would help.



Also, 50 psi in front sounds low. I have always had to run 65 psi in front on any of mine to get decent wear. If it is working for you that's fine, it just sounds low to me.



I just reread your signature. Is it a 2WD??? If so, the shocks could be bad. That will cause flat spots and other odd wear as the tire bounces.



Mike.

 

[jeepit]

Are you talking flat spot as in the first ride of the day after stting all night. My CJ7 does that with bias tires and low air pressure.

Either way, I would reverse the air pressure you have there. I run 60 in front and 45 unloaded rear. and see what you get.

 

[ata]

On my 97 4x4 the front axle is 4100# and the rear is 3200# empty. So I run 65# front and 55# rear. If your talking about what is called CUPPING high and low spots in the tread. Lots of reasons for that shocks,tire balance,tie rod ends, ball joints,loose wheel bearings,alignment. I don't know the mileage on your 98 or what you have had done over the years but it's getting old. Time to start keeping an eye on things.

 

[HBarlow]

Improperly or unbalanced tires will develop wear spots from pounding.

Flat spots appear on synthetic cord tires that are parked for long periods. I've never had a Michelin tire develop flat spots.

I agree with Mike. 50 psi is significantly underinflated on the front axle and also on the rear axle. Even a dually should run at about 60 psi on the rear.

 

[FourBarR]

The decal on the door shows 50 psi this is on 2wd. which is considerable lower weight than 4x4. and as I mentioned in 14 years of using 50 psi I have never had any unusual tire wear. I agree it could be a problem in the front end and I will be taking it to the shop to have everything checked. I will post the results here. Thanks for all your suggestions.

 

[FourBarR]

back from the shop ,checked everything as I watched,ball joints are all tight,tie rod ends show little wear,sector shaft and drag link are all good. checked shocks and show no signs of leakage bounce test by two big guys only one cycle and stop. They do not think that low pressure is the cause of the problem. Why would the factory put a sticker on the door stating 50 psi if it were not correct. Having run this pressure on michelin tires of the same type for 14 years with no problems . Tires show no sign of misalignment ,only slight flat spotting in the center of tread. do not know the answer to this problem. I will run the front tires on the rear to even them up and watch the front tires for signs of flat spots . Thanks for your help and suggestions.

 

[JMcCoy]

Like stated above, your pressures sound low, regardless of what the door says. If you remember, Ford used to recommend a low pressure in the Explorers to improve the ride with the Firestone tires. We all know how that worked out. I worked at Firestone just before that whole issue. The tires always flat spotted from low pressure. Whan we upped the pressure, the tires would wear much better. Low pressure, and heat are the killers. Low pressure also creates heat. If the flat spots are uniform around the tire, your cords are stretching. They will ultimately fail. They will usually fail when the tires get low on tread due to the lack of ability to dissipate the heat. Are your tires D or E rated. I have found the D rated tires I have run are far more susceptible to flat spotting. I currently run 55 lbs front and rear, because that is all my tire will allow, due to their D rating. My tires are very flat spotted and I am sure it is due to low pressure. Florida heat doesn't help either. I plan to go back to an E rated tire soon. Good luck

 

[FourBarR]

Thanks for your comments. The tires are michelin LT245/75/r16 M/S E rated. I do understand the problems with low pressure and the problems it can cause. I have no problem with your opinion on the problem, My only question is why after 14 years of running these same make and type of tires at 50 psi there has never been a problem. Thats the reason I went to the shop to see if there is some other reason. Appreciate your comments ,I will raise the pressures and see how it goes.

 

[ata]

Maybe Michelin changed something in there tires. I ran Goodyear and the last set I bought bounced like basket balls on every bump with the pressures set at 65 front and 55 rear which I had been running. Had to set the pressure at 80 front and rear to get them to stay on the road. Just another guess.