Trailer Tire Cupping

[Steve P]

I'm getting "cupping " type tire wear on the inside edges of both tires. I keep them properly inflated and get them balanced once a year. The trailer is rated to carry 1650 lbs. (2000 lb.GVWR)and total weight of boat, motor and extras is no more than 1250 to 1300 lbs. and the tires are B75 R13.
The trailer is 12 years old and aside from the tire wear issue the trailer is holding up well.My guess is I've got a bent axle.
A new axle with hubs is appx. $125, two new tires about the same price. I don't mind spending that amount if it will remedy the problem, however I don't want to spend the money and find out there is something else causing the problem?
Any insights would be appreciated.

[AquaMan]

LAST EDITED ON Feb-28-01 AT 04:57PM (CST)[p]Bent axle or spindles. Replace or have it straightened and save on tires.

AquaMan~~~~~~~~~~~~~

.·´¯° --- "It all begins and ends at the water's edge"

[prairie walleye]

Axle may be bent but more likely the camber of the spindle needs to be straightened. Happens on my trailer too. I have had my current rig for 3 years and have had the problem corrected twice (too heavy of a boat, not big enough trailer). This problem can be corrected for about $30-40. Frame stretching/tire/frame straightening place should be able to do the job.

[Sparky]

I had the problem until a local weld shop owner, who also happens to love walleye fishing, corrected the problem. I had a bent axle. It has been 5 or 6 years with no further problems.

Sparky

[REW]

The problem is as you have identified it - a bent axle.
It really makes no sense to straighten it - because if it bent once, it will bend again.

Whoever made your trailer - go back to the manufacturer and get the nex heavier axle. i.e. if you have a 1500 lb axle - buy a 2000 or 2500 lb axle.

That way, when you go out and spend the money for the new axle - you know that the trailer is likely to stay fixed.

Assuming that you aren't bottoming out on the springs - the trailer is heavy enough for your boat. You simply need to get a heavier axle.

I had the very same problem on my trailer. The vendor explained that they had a few models of my particular year - where the axle wasn't hardend properly. However, they would not warrent the axle and were charging me for a new one. In my case - to increase the weight rating of the axle by 1000 lbs cost me an additonal $20.00.
I picked up the heavier axle. The axle also included the bearings. The bearings were larger sized id, but the same sized od. Thus, I was able to reused my old hubs. I simply installed the new bearings with seals, bolted the axle on the trailer and I was good to go.

p.s.
I kept the old axle - and speny about an hour one day and ground one end of the axle to a wedge point. This axle makes a very excellent pry bar -- and wedging bar for some of the projects that I run into around the house and garage.
It never hurts to recyle gear.

Take care

REW

[Sparky]

The trailer is now 10 years old and I've only had it straightened once. I checked the load rating of the trailer, axle, and boat weight. I left a healthy reserve for fuel gear, and etc.. It all checked out so I went to the shop. If it ever does it again the axle gets replaced. Thanks for the info.

Sparky

[RD]

I went through this a couple of years ago. I was going thru a set of tires every two years. After advice from this board, I took my boat & trailer to a local shop. They straightened the frame and I have never had another prolem. Tires still look like new. Cost me $85 dollars. They said the trailer of off 3 degrees on bothe camber and caster. I have a shorelander trailer. Bet yours is too. I got at least 75 answers to my original post and all of them were from Shorelander trailers owners.

[Sparky]

Ditto on the Shorelander!

Sparky

[chadk66]

If your boat is truly that light in regards to the axle weight limit, you may want to just take a look at the spring shackles before you take it to a frame shop. If your shackles are wore out,(you noted your trailer is 12 years old) you can get strange tire wear especially on the inside.

[Steve P]

What type of shop does this type of repair and straightening. I've called several tire places that would normally do allignments and they did not want to try bending something to straighten a misalignment? Help, or new axle here I come.

Thanks to all for the feedback

Steve

[Steve P]

What exactly am I going to be looking for as far as wear is concerned on the shackles and would it be likely to be uniform on both Sides?

[REW]

Nearly any "high end" alignment "only" shop will straighten a frame or axle to get the alignment.

The "tires plus" or high volume tire dealers don't have the capability -- but nearly any shop that does only alignments - will be able to take care of this bending.

Another place to go - if you don't have a shop like this in your area --- is to simply go to any nearby body shop.

Many of the body shops have alignment capability in their frame shops with all of the laser guided alignment tools and measuring devices as well.

Take care

REW

[Tim P]

30 + years as an alignment specialist & I can tell you If you trully have cupping on BOTH sides of youre tiresThe ONLY thing that is causing it is vibration. The tires HAVE to be bouncing to develop that kind of wear pattern. No alignment is going to correct the problem. First off I'd suspect the balancing. You did not mention the size but IF they are smaller than 13" most auto shops do not have the balancers that are sensitve enough to really do a good job on small tires. Try a shop (usually a H.D.truck shop)that can bal. ON the veicle. Could also be caused by less than premium tires Buy the best. As long as everything is tight & the axle/spring/tire combo is not over loaded You should have no more problems. One other thing, once a pattern has started the only way to get rid of it is to replace the tires. Acupped tire will continue to cup even if everything else is corrected.The guy that sugested a PRO alignment shop was on the right tract IF your axle is bent Just be sure to look for one that has the equipment AND THE MECHANIC to bend axles. It's not rocket science but the man has to know what he's doing. good luck!

[cut bait]

Tim P. I believe the original post said that he was getting the cupping on the inside edge of BOTH tires not cupping on both edges. Thanks for the info though. Any new advise?

[Westy]

I have used alignement shops that cator to big over the road trucks for my boat trailers They have the equipment and are very knowledgeable.