Caues of uneven tire wear?

MillWeld · Apr 1, 2017

My tandem trailer tires are showing uneven wear, especially the left front and right rear. (The left rear and right front tires show almost the same wear). Measurements with calipers show more than 0.1" difference with the most wear occurring on the trailer side (inside).The tires are 6 years old, probably less than 1000 miles. The axles are 5400 lb ALKO (purchased used). I installed brake kits and wheels/tires from eTrailer and welded on axle seats myself. Any advice on what caused this and how to correct it?

sweettractors · Apr 1, 2017

Is it possible the axles are not square with the center line of the trailer pull? Ken Sweet

Rocky J · Apr 1, 2017

Most axles have a arch up and is installed up so it goes straight when loaded. If it was rotated forwards or backwards it could cause a toe out or in . If you can place the palm of your hand on top of the tire tread and slide it in to the trailer and back out and feel for feathering,(edges felt one way but not the other) if both tires on that axle are feathering out then it is toed out and the opposite equals toed in. If the two tires on the same axle both feather the same direction then the axle is dog tracking (trying to go to the left or right of the road even though you are pulling it straight). Like you said they were used so the possibility of abuse is there. When I set toe in on semi tractors I took a 4 x 4 block and drove a 16 penny nail point at a angle to scratch the tire, jacked up the axle spray painted the center of the tires tread as I spun them, after they dried I spun them again and pushed the 4 x 4 with nail into the tire to make a scratch all the way around the tire, then with a tape measure compare the front measurement to the back, then adjust. In your case it would be rotating the axle to correct or replace.

Redlands Okie · Apr 2, 2017

Rocky J said:
Most axles have a arch up and is installed up so it goes straight when loaded. If it was rotated forwards or backwards it could cause a toe out or in . If you can place the palm of your hand on top of the tire tread and slide it in to the trailer and back out and feel for feathering,(edges felt one way but not the other) if both tires on that axle are feathering out then it is toed out and the opposite equals toed in. If the two tires on the same axle both feather the same direction then the axle is dog tracking (trying to go to the left or right of the road even though you are pulling it straight). Like you said they were used so the possibility of abuse is there. When I set toe in on semi tractors I took a 4 x 4 block and drove a 16 penny nail point at a angle to scratch the tire, jacked up the axle spray painted the center of the tires tread as I spun them, after they dried I spun them again and pushed the 4 x 4 with nail into the tire to make a scratch all the way around the tire, then with a tape measure compare the front measurement to the back, then adjust. In your case it would be rotating the axle to correct or replace.

Interesting. Thanks.

MillWeld · Apr 2, 2017

When I bought the trailer it has MH axles on it which I replaced with the ALKOs which are straight - no arch. I used the same hanger points the original axles hung from. I really don't understand how the pull point being off can cause what I have - excess wear on the inside of 2 tires on opposite axles. To me it is like I have a lot of negative camber on the ill-worn tires. I was thinking I may have distorted the axles on one end when I welded on the spring seats. The spring seats are on top of the axle and welding too hot would draw the top in a bit causing the negative camber. Does that make sense??

Concerning the "feathering" - how could I rotate the axle with welded-on seats? Mine being straight, there would be no gain in rotating them anyway. Correct?

Thanks for the comments.
Bob

Rocky J · Apr 2, 2017

What you are saying makes sense, welding the spring saddles on with a lot of weld and building a excess in heat could have pulled the carbon from the surrounding area of the axle tube around the saddle to the weld and making it softer and capable of bending .Everything I weld pulls some no matter how much tacking I do. Yes you would have to remove the saddles to rotate them if it was needed. I think you need to start with the scratch line on both tires on one axle and measure to compare front to back and top to bottom to be sure there is a difference and shows a relationship with the tire wear . I can tell you have put a lot of thought into this by your answer and you are probably right it has just hit a chuck hole and bent each axle at different times.

crazyal · Apr 2, 2017

I would start off by simply getting a nice straight piece of steel and placing it on the outside of one of the tires and making sure that the other tire on that side was parallel with it. Here's a good link to basic checks you can do.
Trailer Axle Alignment and Tire Wear Problems

PILOON · Apr 2, 2017

crazyal said:
I would start off by simply getting a nice straight piece of steel and placing it on the outside of one of the tires and making sure that the other tire on that side was parallel with it. Here's a good link to basic checks you can do.
Trailer Axle Alignment and Tire Wear Problems

Excellent link showing easy methods to check alignment.

Diamondpilot · Apr 2, 2017

We see this a lot. My guess is you are out of alignment. You can get it aligned at a semi trailer shop. My guy uses hydraulics and a frame straightener.

MillWeld · Apr 3, 2017

Thanks for the good info. I will make some of the measurements in crazyal's link for my own education and will probably end up taking it to a trailer shop as Diamondpilot suggested.