Opinions on Worn Tire

[Dale M.]

I'm pretty much in the school with others on over inflated is main cause of center wear, and sigh off center is maybe bent axle or lack of camber in axle...

Funny, a year or so ago this same thing came up about tire inflection and there were some in the school that inflation pressure in tire side was gospel and if it was not inflated to that pressure it was wrong.... Well here is proof that inflation pressures are weigh/wear related...

As for alignment, its a simple thing... if trailer is running a "crab" angle, the axle is severely out of line, it trailer is running straight, axle is aligned Its going to self align its self from hitch point where tires are running to their own best angle by tire drag... Simple measurement from ball hitch to tip of spindle will tell... Measurements should be equal ...

Dale

[KCStudly]

An argument can be made that with the battery offset to one side, and excess toe (either positive or negative) that the tire with the weight would have more traction and track true, whereas the tire with less weight would scrub more, even just a little more without resulting in visible crabbing. Over 4500 miles this difference might be enough to wear one tire and not the other. I'm not saying that this is absolute, but in my mind it is one possible explanation.

Place a straight edge up on paint cans across the outside of each tire (above the bulge) and measure very accurately from one straight edge to the other, right at the tread, both in front of and behind the tire and see what the toe is (if any), then measure very accurately from the frame rail to the edge of the tread (or center line of the tire) on both the front and rear of both tires; compare these numbers and see what it tells you.

I would think that anything more than 1/8 inch toe in either direction (toe in preferred) would be a concern (in diagnosing the stated problem, IMO). On the side to side frame rail measurements I would look closer if something is different by more than 1/16 inch compared to the opposite side.

Again, 9 times out of 10 this level of scrutiny is probably not called for, but with a known tire problem it is a simple check that can provide useful information at where the problem might be.

[ctstaas]

Hi Everyone, The first thing I would check is the tire tow in/out. Measure from tire to tire in the front and back as close to the horizontal center line as possible. Towed in slightly is OK but towed out is bad. The measurement should be equal ( front and back) or slightly less in the front. Ideally, the tires should be parallel to the center line of the trailer.
It could be a defective tire?
My tire guy hooked me up with very good tires. They weren't cheap, but confidence is worth how much?
Enjoy, Chris

[Nobody]

Recently had a similar experience with my TD tires except it was on a much shorter trip.

I built my TD in 2006, on an HF 1800# trailer (think that trailer is now called a 1720# or maybe 1740# trailer??). I towed the TD for over 15K miles with the original tires & had no problem. Travel varied from freeway to back country trails but mostly on open highway at 55-65mph. Always ran about 40-45lb pressure & TD weighed 1200 to 1350lbs loaded. These were Duro (Chinese?) brand tires rated for 1045lbs @ 80psi max).

In 2010 we drove thru some flooded areas in SE New Mexico after torrential rains. Apparently some water entered the hubs & after we returned home I discovered it & replaced seals & the slightly discolored bearings. About that time or in 2011 I also replaced the original tires while preparing for a trip to/from California (bought the Hi-Run 530-12 tire/wheel combo from local WalMart). We did the California trip in just over ten days (too much driving for an old man ). Tires showed negligible wear after that trip & absolutely NO odd or unexplained wear (tire pressure approx 35-36lbs). Between 2012 & this year I'd put probably another 1K miles or so on the TD in shorter, 3-400 mile trips. In preparing for our trip last month driving the Natchez Trace Parkway in MS, AL, & TN, I inspected the tires & noticed that they'd been wearing the 2 tread ribs adjacent to the center rib. I concluded they were probably under inflated so using same logic as angib touts in his post above, I calculated that with my trailer rolling weight (approx 1050/1100 lbs) & tire max capacity (1045lbs @ 80psi) = 525/550lbs each tire, I should be running about 42-43lbs so I increased tire pressure to 43psi.

At the end of our first day on the Pkwy I noticed that the driver side tire on the TD appeared to be 'scrubbing or scalloping' the 2 inner tread ribs while the curb side tire appeared to be wearing the 2 outer ribs the same way?? We spent the rest of that week driving the parkway (max speed 50mph) with a short distance driven on I-40 in TN (maybe 60mi) before returning to the parkway driving south. By the time we left the parkway near Tupelo, MS heading home, the curb side tire had begun to wear quite badly, mostly on the outer ribs but continuing past the center rib much as mikereuve shows in his pic. By the time we returned home, 1300 plus miles, the curb side tire was worn nearly 'bald' from outer rib, past the center rib, & the driver side tire had considerable 'scalloping' on the inner 2 ribs.

I was at a loss for a solution except I thought the axle might possibly have slipped a little in the spring shackles toward the rear on the driver side. When the TD was a couple of years old (2008 or 2009) & before replacing theoriginal tires I'd added a steel 1" spacer between the axle spring perch & the springs, to give me some additional clearance between my tires & the wheel wells. I'd drilled a hole in the top of the spacer for the spring bolt but made no provision for a 'dog' on bottom of spacer to fit the hole in the spring perch. That change had caused NO problem of tire wear with the original tires & throughout the California trip (more'n 4K miles). I pulled the wheels & hub dust cover in preparation for measuring from the 'countersink' in the spindles to center of coupler. I carefully inspected the axle & springs, the 'spacer' was still in place & square with both the springs & the spring perch.

When I measured from the spindles to center of coupler, there was nearly 1/4" difference but the driver side was the shorter, not longer as I'd expected?? I loosened the spring/axle 'U' bolts & again 'squared' the spindles to the coupler, as I'd done in initial construction, after installing the spacers, & after the rear end collision in 2010. After each of those operations I had less than 1/16" difference in measurement from axle spindle to coupler center. Every measurement I've taken indicates the axle is still square to the trailer chassis & the axle is again square to the coupler.

I'm reluctant to believe that an increase of tire pressure from 35/36lb to 43lb could grossly overinflate the tire(s) enough to cause such wear but I'm left with not much more than that to conclude. I'm sure that 1/4" difference in length from spindle to coupler (in a distance of only 120" approx) could cause considerable wear but the difference was on the wrong side IME.

Anyway, I ordered a pair of new Carlisle Sport Trail tires in load range 'C' (same rating as my other tires), had 'em mounted & balanced, & they're in place on the newly re-squared axle. We have an approx 3500 mile round trip planned for next month to the Walk the Winds gathering in WY. I've dropped tire pressure on the new tires back to 38/39psi & will carefully monitor tire wear & make appropriate adjustments throughout the trip.

Unfortunately I didn't take any pix of the WalMart tires before replacing them with the Carlisle tires. I do have a new set of the WalMart tires on a small Starcraft Meteorite pop-up trailer but haven't towed it any distance since they were mounted so don't know how they'll do. I've had pretty good performance with the Hi-Run tires in the past so hopefully this was an aberration or a simple matter of over inflation...

[eamarquardt]

As for alignment, its a simple thing... if trailer is running a "crab" angle, the axle is severely out of line, it trailer is running straight, axle is aligned Its going to self align its self from hitch point where tires are running to their own best angle by tire drag... Simple measurement from ball hitch to tip of spindle will tell... Measurements should be equal ...

Dale

Simply put, there's more to it than what is stated above.

Toe in can be correct on one side and incorrect on the other. Same with camber. A frame shop can get it right.

Cheers,

Gus

[mikerueve]

Again, I thank everyone for their thoughts and insights. I'm definitely going to take some measurements.

I'll also look into finding a frame shop if nothing is apparent.

[Socal Tom]

[quote="Nobody"



When I measured from the spindles to center of coupler, there was nearly 1/4" difference but the driver side was the shorter, not longer as I'd expected?? I loosened the spring/axle 'U' bolts & again 'squared' the spindles to the coupler, as I'd done in initial construction, after installing the spacers, & after the rear end collision in 2010. After each of those operations I had less than 1/16" difference in measurement from axle spindle to coupler center. Every measurement I've taken indicates the axle is still square to the trailer chassis & the axle is again square to the coupler.

I'm reluctant to believe that an increase of tire pressure from 35/36lb to 43lb could grossly overinflate the tire(s) enough to cause such wear but I'm left with not much more than that to conclude. I'm sure that 1/4" difference in length from spindle to coupler (in a distance of only 120" approx) could cause considerable wear but the difference was on the wrong side IME.

. ..[/quote]

Out of balance tires can also cause the scallopping, and so can poorly built tires. Running tires underinflated can also lead to a situation that starts the scallopping and once it starts putting the air back in won't fix it.
Tom

[Nobody]

[quote="Nobody"



When I measured from the spindles to center of coupler, there was nearly 1/4" difference but the driver side was the shorter, not longer as I'd expected?? I loosened the spring/axle 'U' bolts & again 'squared' the spindles to the coupler, as I'd done in initial construction, after installing the spacers, & after the rear end collision in 2010. After each of those operations I had less than 1/16" difference in measurement from axle spindle to coupler center. Every measurement I've taken indicates the axle is still square to the trailer chassis & the axle is again square to the coupler.

I'm reluctant to believe that an increase of tire pressure from 35/36lb to 43lb could grossly overinflate the tire(s) enough to cause such wear but I'm left with not much more than that to conclude. I'm sure that 1/4" difference in length from spindle to coupler (in a distance of only 120" approx) could cause considerable wear but the difference was on the wrong side IME.

. ..

Out of balance tires can also cause the scallopping, and so can poorly built tires. Running tires underinflated can also lead to a situation that starts the scallopping and once it starts putting the air back in won't fix it.
Tom

Yeah Tom, I concluded that imbalance probably contributed a lot to my problem. That's why I had the new Carlisle tires balanced & will carefully monitor the tire pressure, not only for this trip but all the time. I always pay close attention to my tires, wheels, & hubs as well as lights, coupler, hitch, etc. I'll just be a little more diligent than before...

[ctstaas]

Hi , Air pressure is the first to check because it is so easy to do. Second, measure the distance between the tires on the horizontal plane, front and back. The front and rear dimensions should be the same. The dimension in the front can be 1/8" less maximum. It looks like your tire has scrubbed. I think that's what they call it when a tire is not running parallel to the direction of tow.
Enjoy, Chris

[highdesertranger]

what brand tire was this? was it a el cheapo Chinese tire? it does look like over inflation. highdesertranger

[mikerueve]

They were the tires that came on the Northern Tool trailer kit. I believe that the quality does leave something to be desired. That said, I'm trying to find a place that can check the alignment of the wheels right now.
I believe the passenger side is not aligned properly. I think the front of the tire "toes in" a bit too much.

[RPH]

I think I my have found the problem with the unevenly worn tire. Everything I have read on this thread is based on the assumption that the Hubs; bearings; and spindles are accurately manufactured and that the problem lies with the trailer alignment or tires.

The truth is that the Harbor freight hubs are very poorly made. I presently own six Harbor Freight hub assemblies. Two are from an older trailer and are of cast ductile iron. The other four are from a new trailer and are made from three parts that have been assembled by welding and in this welding process the disc portions, that part of the hub to which the wheels are attached, are in most cases not properly aligned with the cylindrical portion. The result is that the hub face reveals a pronounced “wobble” when it is spinning. This “wobble” is then magnified in the tire and will certainly cause uneven wear.

My observation of the older cast iron hubs indicated that they were a little more accurately made. Another fault, however, is that the castle nuts were poorly made in that their mating faces are not square with the axis of rotation. The result of this is that when they are tightened (with the prescribed torque) they forced the bearing races out of alignment. This in turn causes misalignment of the hubs and in time damages the bearing races; spindles; and maybe even the hubs themselves.

My suggestion is to jack up the trailer and spin each wheel and see if there is any “wobble” in them. If there is any wobble check to see if the hubs are of the welded type rather than cast iron. If they are welded there is nothing you can do but replace them with new hubs from another source. Harbor Freight will replace them under warranty but with the same junk as before.

I would also suggest to everyone who owns a Harbor Trailer to look closely at the hubs. Inspect the bearings; spindles and races on a regular basis for any damage and replace them if necessary. Also everyone should replace their castle nuts because all of them are poorly machined and will probably mess up the rest of the assembly. Do not replace the “Chinese” tires with expensive quality tires until you are sure that everything is working properly. Let the Chinese tires take the abuse until everything is in tune.

[Shadow Catcher]

We replace our ST tires with Micheline Harmony passenger car tires, weight capacity for each tire is less than the weight of the trailer. More tread depth a real warranty and not made in China. We did check alignment and had wheels balanced.

[kd8cgo]

So this thread is a little old, but I wanted to add some extra things to think about in the relationship of tires and suspension. Normally tires are inflated to correspond to the load on that tire. So, an 80 PSI max. inflation tire rated for a specific max. weight rating of 1340 lbs, should be inflated up to the max. as your axle weight approaches 2680 lbs. An empty utility trailer that has 240 lbs per tire loading, is sometimes necessary to run inflation down all the way to 10 or 15 PSI in some cases, to prevent dangerous bouncing conditions caused by having such a high spring rate vs. the current load on the axle.

Sometimes we will bump up the tire pressure simply to get better mileage. This usually poses a minimal problem on our vehicle tires, often nothing more than a harsher bump response. A trailer, depending on the design, can respond quite differently.

Leaf sprung trailers are the most likely to cause tire symptoms due to increased inflation. In order to cut costs, most American companies do not put dampers or shock absorbers on a leaf sprung trailer, including the HF kits. Spring steel oscillates after absorbing a bump, because they conserve energy rather than dissipating it, so one pothole makes a bounce bounce bounce bounce... on the trailer. Tires, being rubber, tend to absorb and dissipate that bouncing energy, so the oscillations are much shorter and less severe. A over-inflated tire does not let the sidewall flex as much, which limits the ability to smooth out those bounces. The tires hop on the roadway, even if they don't come off the ground, they have a dynamic load component, and the carried weight is changing constantly while under way. The most prominent symptom of this effect is tire cupping or scalloping. Depending on the jounce in the suspension, a few PSI can take away the sidewall's ability to dampen the spring reaction forces. It's like bouncing a flat basketball vs. a really firm basketball.

Rubber torsion axles do not conserve energy like a steel spring, and dissipate jounce more quickly on their own. They are much less prone to show a tire symptom like this over a larger range of inflation pressure, because they do not rely as much on the sidewall for damping the spring reaction force.

With the HF trailers we also have to contend with the higher likelihood of quality issues. Loose or misaligned wheel bearings or races, and non-concentric bearings and hubs are big ones. I have an older HF folding trailer and the hub runout is not too bad. When you combine a bad hub runout where the hub and wheel/tire moves in an elliptical pattern around the spindle as it spins, it causes all sorts of crazy weird tire symptoms to show up, including the scalloping and cupping. You can check runout with a dial indicator. This all has already been mentioned, but I figured I'd add a blurb about it.

The last thing is non-centered wear on the tire, side to side. This can be any of the above causes, plus more - and maybe they only show up at certain tire pressures and trailer weights. Many production axles are cambered from the factory this mean the tires are tilted top to bottom, usually they use positive camber so the tires sit like this on an empty trailer:

\ ---- /
That is called positive camber, and it will wear the outside edge of the tire. When the trailer is loaded up to its axle design capacity, the axle will yield and the camber will do this:

| ---- |
Which is called "neutral" camber. The axles are designed to be under load in this case, and wear the tire more evenly while there are high loads on them. If you run a really oversize axle, it will never yield, and could run more positive camber than you might like.

The last camber situation would be negative camber:
/ ---- \

This would be common if you put a small axle on your trailer and run overloaded. It commonly wears the inside edge of the tire. Some manufacturers might also design some negative camber to keep the trailer from sliding out during cornering, although this is more common on cars and less common on trailers. If the outside tire rolls and the vehicle leans, the negative camber can help keep the tire contact patch more even on the roadway when it counts the most, in a sharp corner.

There is another component of alignment on a trailer and that is the tow settings. We call it tow in or tow out. Easiest way to remember it is look at your feet. Stand pigeon towed and your toes are pointing in towards each other - tow in! Do a duck walk and your toes are pointing out - tow out!

Excessive tow settings are what cause the tires to scrub, since they try to push in towards each other, or away from each other while rolling on the road. "Scrub" is the tire sliding at a angle on the road instead of rolling straight and true on it. Many manufacturers will put a small tow in on an axle. This is often reasoned because as you drag an axle down the road, it will tend to flex backwards ever so slightly in response due to friction. This small tow in setting becomes a neutral tow setting while under way. A tow out condition can cause the trailer to yaw more, inducing sway or wander. If you are towed in, you will normally wear the outside edge of your tire. Tow out will normally wear the inside. Tow affects tire wear faster than camber - scrubbing is a rougher activity than just rolling on a slight camber angle, in or out.

It can take special tools to sort out a niggly alignment or tire wear issue - you can make your own - but the pro's have the most experience and tools to sort you out. Alignment and frame specialty shops can take and adjust all the precise measurements if you can't figure it out on your own. Often times you need hydraulics and things to bend axles into submission.

A lot of people here already know all this and more, but I figured a simple post might help at least one person down the road.

[pchast]

Thanks!