My 13-footer sits on a galvanized E-Z-Loader trailer with 12-inch wheels and torsion springs. I am experiencing what I consider unusually high tire wear and an unusual tire wear pattern. Load Star radial load range D tires were put on new in October 2019. Tires are inflated to the maximum 65-PSI. On a 2,500-mile round trip from Ohio to Florida and back, both tires were worn about 1/16-inch on the outside part of the of the tread, and very little on the inside. The same thing happened on the prior set of new tires.
I measured the distance from the coupler to the outside edge of the tire. ( I would like to measure directly to the center of the hub but the tire is in the way and I haven't figured out a good way to get at the hub for a direct measurement!). The left tire is 1/4-inch further to the rear of the trailer than the right tire. I've measured each side several times and I get the same measurements.
I can see how the axle being out of square would cause tire wear, but it seems like it would wear evenly across the tread of both tires.
Q: is 1/4-inch out of square a lot?
Any suggestions on how to take a measurement directly to the center of the hub?
It looks like it's just a matter of loosening a couple U bolts to adjust the axle fore and aft.
Thanks for your help.
Trailer Tire Wear
Re: Trailer Tire Wear
Is there any deflection of the axle when the boat is on the trailer from the loading (or lack of loading) on the axle?
What is the weight rating on the axle?
What is the total trailer weight with the boat loaded?
- Fig. 1. A bowed axle could cause uneven tire wear on the outside edge of both tires.
- bowedAxle.png (8.8 KiB) Viewed 4304 times
What is the weight rating on the axle?
What is the total trailer weight with the boat loaded?
Re: Trailer Tire Wear
Jim, thanks for your comments. I think the mystery is solved. The axle is indeed bent upward as you show in your sketch. I was able to lay a 36" long straightedge against the underside of the square tubular axle and there is about a 1/8" gap at the center. (measured with allen wrenches). As I looked closer at the axle with better lighting I can see and feel a sizeable depression on the underside of the axle near the center which I believe bent the axle upward due to an impact. It looks like the trailer probably bottomed out on the bottom of the axle and bent it. It must have happened to one of the two previous owners.
I don't live near a body of water where I could easily offload the boat for further measurements. However, I was able to jack the trailer frame up a few inches which took almost all of the load off the axle. I remeasured the axle straightness and the same 1/8" bow is still there. So it does not appear to be a function of the load but the axle is simply bent.
I could buy a new axle or I could take it to a frame shop but a new axle would probably be less expensive. I may just live with it.
The axle is rated for 1560 pounds. I have had the entire loaded rig weighed on a certified scale at 970 pounds. This included boat, motor (40hp 2 stroke), trailer, full fuel, trolling motor and all my gear.
I don't live near a body of water where I could easily offload the boat for further measurements. However, I was able to jack the trailer frame up a few inches which took almost all of the load off the axle. I remeasured the axle straightness and the same 1/8" bow is still there. So it does not appear to be a function of the load but the axle is simply bent.
I could buy a new axle or I could take it to a frame shop but a new axle would probably be less expensive. I may just live with it.
The axle is rated for 1560 pounds. I have had the entire loaded rig weighed on a certified scale at 970 pounds. This included boat, motor (40hp 2 stroke), trailer, full fuel, trolling motor and all my gear.
Re: Trailer Tire Wear
It looks like about $150 can solve the problem:
https://www.easternmarine.com/1-1-2-square-1560-lbs-ez-loader-trailer-axle-25073-10
I have had good luck with that on-line seller of trailer parts. Shipping might be expensive. Sometimes you local boat dealer that sells E-Z-LOADER trailers might be able to order it and you won't have to pay for shipping. It could come on a load with other trailers for other dealers. They tend to stack up a dozen trailers on one truck and make deliveries to many dealers off that one load.
Look at the cost this way: replacing two tires that wear out early will cost more than that.
But check with E-Z-Loader to make sure the the axle is not pre-bend slightly in anticipation of loading. I don't know if that is possible, but it can't hurt to check.
ASIDE: although removing the old axle will be a messy job, it will allow you to inspect the wheel bearings and grease seals. It may be a good time to replace the grease seals and inspect and re-grease the bearings.
https://www.easternmarine.com/1-1-2-square-1560-lbs-ez-loader-trailer-axle-25073-10
I have had good luck with that on-line seller of trailer parts. Shipping might be expensive. Sometimes you local boat dealer that sells E-Z-LOADER trailers might be able to order it and you won't have to pay for shipping. It could come on a load with other trailers for other dealers. They tend to stack up a dozen trailers on one truck and make deliveries to many dealers off that one load.
Look at the cost this way: replacing two tires that wear out early will cost more than that.
But check with E-Z-Loader to make sure the the axle is not pre-bend slightly in anticipation of loading. I don't know if that is possible, but it can't hurt to check.
ASIDE: although removing the old axle will be a messy job, it will allow you to inspect the wheel bearings and grease seals. It may be a good time to replace the grease seals and inspect and re-grease the bearings.
Re: Trailer Tire Wear
I definitely will call Eastern Marine.
After further research it appears many trailer axles are made with a bow to straighten out under load. so, I'm not sure now if my axle is bent but it certainly has a bow even with the fully loaded boat on it.
My axle is different and more expensive than the one you referenced.
https://www.easternmarine.com/loadrite- ... le-6227-90
\
The axle is made by a German company by the name of Knott GmbH and the bearings are supposedly greased for life. The only option is to replace the entire hub assembly (which I have done, and I carry a spare hub). It's not the typical design hub assembly with replaceable bearings used on most trailers. I didn't know this until after I bought the boat.
After further research it appears many trailer axles are made with a bow to straighten out under load. so, I'm not sure now if my axle is bent but it certainly has a bow even with the fully loaded boat on it.
My axle is different and more expensive than the one you referenced.
https://www.easternmarine.com/loadrite- ... le-6227-90
\
The axle is made by a German company by the name of Knott GmbH and the bearings are supposedly greased for life. The only option is to replace the entire hub assembly (which I have done, and I carry a spare hub). It's not the typical design hub assembly with replaceable bearings used on most trailers. I didn't know this until after I bought the boat.
Re: Trailer Tire Wear
If the OEM axle is slightly pre-bent intentionally by the manufacturer in anticipation of flex under load, there may be no remedy for the uneven tire wear.
The axle is rated for 1,560-lbs. The total trailer weight is described as 970-lbs. We can assumed that perhaps as much as 10-percent of the total trailer weight, say 100-lbs, occurs as a load on the tongue of the hitch of the towing vehicle. So the actual weight on the axle is then about 870-lbs. That suggests the load weight on the axle is only about 56-percent of the maximum rated load.
The light loading on the axle may be the cause of the uneven tire wear. If it turns out there really is not a defect in the axle on the trailer now, and it indeed had some pre-bend designed into it, then the uneven tire wear may have to tolerated.
The axle is rated for 1,560-lbs. The total trailer weight is described as 970-lbs. We can assumed that perhaps as much as 10-percent of the total trailer weight, say 100-lbs, occurs as a load on the tongue of the hitch of the towing vehicle. So the actual weight on the axle is then about 870-lbs. That suggests the load weight on the axle is only about 56-percent of the maximum rated load.
The light loading on the axle may be the cause of the uneven tire wear. If it turns out there really is not a defect in the axle on the trailer now, and it indeed had some pre-bend designed into it, then the uneven tire wear may have to tolerated.
Re: Trailer Tire Wear
Have you tried different tire pressures? Have you tried doing that with a chalk or grease pencil line to see how uniform the wear is?
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).
Re: Trailer Tire Wear
biggiefl, no I choose to run at the max pressure. I have not experimented with tire pressure. Likewise, I have not used chalk to see the tire contact pattern. May try that.
Re: Trailer Tire Wear
Max pressure is just that. It does not say to run max pressure but you should not exceed it, same goes for your car/truck. The tire says max pressure but your vehicle's has a label (usually on the door jam] that gives recommended inflaton.
If I ran the max tire pressure in my car my teeth would fall out if i hit a bump and my tires would not wear evenly. I usually run around 5 to 10-PSI less than maximum on trailers. When those tires get hot, pressure goes up as well. My money is on tire pressure, especially with a small 12-inch tire.
If I ran the max tire pressure in my car my teeth would fall out if i hit a bump and my tires would not wear evenly. I usually run around 5 to 10-PSI less than maximum on trailers. When those tires get hot, pressure goes up as well. My money is on tire pressure, especially with a small 12-inch tire.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).
Re: Trailer Tire Wear
biggiefl, if the problem is tire pressure it would seem like the tire would wear fast in the center, not on one side.
Re: Trailer Tire Wear
NICK has a good suggestion regarding tire inflation. As presumed above, the actual axle load is perhaps as low as 870-lbs. The load on one tire is then about 435-lbs. I anticipate the trailer tire maximum load rating is probably more than 435-lbs by quite a big margin.
If the tires you have happen to be
LOADSTAR ST145/R-12" RADIAL Tire, Load Range D
then, according to a vendor website (Eastern Marine), they have a maximum load rating of 1,220-lbs each at 65-PSI. You have a lot of margin in load rating when the actual load is only 435-lbs.
Reducing inflation might result in a change in wear pattern.
I don't know how to predict the change. However, if the tires are not rock-hard, perhaps the tread will better conform to the road surface and wear more evenly.
If the tires you have happen to be
LOADSTAR ST145/R-12" RADIAL Tire, Load Range D
then, according to a vendor website (Eastern Marine), they have a maximum load rating of 1,220-lbs each at 65-PSI. You have a lot of margin in load rating when the actual load is only 435-lbs.
Reducing inflation might result in a change in wear pattern.
I don't know how to predict the change. However, if the tires are not rock-hard, perhaps the tread will better conform to the road surface and wear more evenly.
Re: Trailer Tire Wear
Ding ding....well said Jim
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).
Re: Trailer Tire Wear
Assume the axle center to wheel distance is 48-inches. The axle is reported to be 0.125-inch out of true. The resultant angle the tire will make with the road surface will then be slightly off. How much off? I calculated about 0.15-degree off. That seems like a miniscule amount of angular misalignment of the tire to the road.