New Axle Called For?

[daniel123]

When putting my boat away for the winter I noticed that the new-last-season Loadstar/Kenda 205 75D-14 tires are showing excessive 'cupping' wear on the inside edge of each. Since they both show the same inside wear, I'm thinking whatever is causing it is happening to both sides at once and that it might be a weak axle, bending down under the weight of the boat and forcing the tires outward and putting more load on the inside edges of the tread? It's a 1999 single-axle Continental aluminum holding a 1999 200 Osprey. It was a FLA/saltwater rig before I found it here in OH-IO, and there is some surface rust showing on the rectangular beam that holds the axle. Any thoughts/advice?

[wingtime]

If the axle was bending due to rust  through the amount of the bend would be pretty severe (think cracking and getting ready to break).   Surface rust on the outside is a non issue.  Just wire brush it, treat it with OSPHO rust converter, and then spray on a coat of cold galvanizing compound to protect it.   Rust scale you need to hit it with a hammer to knock off the scale.  If the damage isn't too bad treat as above but keep an eye on it.

It sounds like you have a 3500 lbs axle.  If you ask me I think the axle is just overloaded and the axle is flexing under the load.  A 20' boat should be living on a tandem axle trailer.  The best thing you can do is find a public truck scale and have it weighed.  It should cost you $10-$20.  That way you will know exactly what the load is on the trailer.  Most scales will let you do a tare and loaded weight for the same fee.... so you can weigh your rig... then go put the boat in the water and weigh it again.  Then you can subtract the weight of the trailer and get the actual weight of the boat.  Oh and if you can do this with the boat fully loaded.  You know full of fuel, gear, coolers etc.

[flounderpounder225]

When putting my boat away for the winter I noticed that the new-last-season Loadstar/Kenda 205 75D-14 tires are showing excessive 'cupping' wear on the inside edge of each. Since they both show the same inside wear, I'm thinking whatever is causing it is happening to both sides at once and that it might be a weak axle, bending down under the weight of the boat and forcing the tires outward and putting more load on the inside edges of the tread? It's a 1999 single-axle Continental aluminum holding a 1999 200 Osprey. It was a FLA/saltwater rig before I found it here in OH-IO, and there is some surface rust showing on the rectangular beam that holds the axle. Any thoughts/advice?

You may be correct on the axle weakening and flexing undr the load, putting a long straight edge along the bottom of the axle might help confirm that.  Also, most axles coming from axle MFGs and not home-made ones, usually have a positive arch or curve put into them during manufacturing, so they resist a negative flex under load, I have heard of people putting them in wrong (upside-down).  As far as the rust, get a hammer and see how bad it is, usually on these trailers when you see rust forming on the outside of an axle tube or frame piece of box tubing, it means the rust on the inside is fairly advanced.  That is probably a borderline trailer for a 200 Osprey, how many lug nuts does it have?  The biggest 5-lug hub is going to be a #3500 lb axle.  May be time to step up to tandem, or a larger single #6000 axle

[wingtime]

I was going to mention the pre-loaded axles but Marc beat me to it.

[gman 82 aquasport]

The only true way I have figured out to check an axle to see if it's bent or if the end is bent is to have it off the trailer and sitting on a level floor and measure the distance from floor to axle stub end....Bent one end of one of my 8 month old axles by hitting a nice state of North Carolina Road dept. pothole ...Bent the stub about 1/4 inch and it started wearing that 1 tire on the inside..New axle purchased  and awaiting install...Sounds like it may be time to upgrade yours to a tandem set-up..Just my .02

[Georgie]

Daniel,

Another thing to consider, but are you running bias ply or radial tires?  I've found bias ply will cup-wear like you describe when carrying relatively heavy loads (i.e. 20 ft. osprey on a single axle   ).  However, in my experience they usually wear on the outside corner, not the inside corner like you describe.     Radials are bouncier and don't retain their vertical shape as well as bias ply (my radials constantly look like they're low on air pressure even when they're at max rated pressure), but I find they are much more laterally stable due the belted reinforcement and my tires now wear evenly instead of having the corners chewed up after a couple thousand miles.

[daniel123]

Great advice, guys. Not sure what to do at this point. But I will have it weighed next spring when it gets back into commission. I'm not in a position financially to buy a new trailer - and I like the aluminum Continental it's on, as I do drop into salt once or twice a season. Continental has offered to sell me a replacement axle and hardware to replace the present one. Maybe I should ask them for an upgrade from the #3500 one you tell me is likely on there now, to a #6000 class? Or maybe get another #3500 axle assembly (or keep the present one and just add the new one?) and convert it onto a tandem? As for tires, I am running Kenda K550 14 inch bias ply five-lugs. I'll upgrade to radials if you guys agree they will help with the wear issue. Is there a round axle inside the rectangular tube with the surface rust -- and is that axle what may have 'advanced' rust? Just curious about how that is constructed. As always, thanks for the advice!

[Capt. Bob]

Is there a round axle inside the rectangular tube with the surface rust -- and is that axle what may have 'advanced' rust? Just curious about how that is constructed.

No.
The spline is welded onto the channeled "axle". The hub revolves around the fixed spline. It does not have an axle like a car with rear wheel drive has but on the same note, it is similar to that same car's front wheels. That's why it's important to keep the bearings inside the hub properly lubricated.

The wheel is attached to the hub (lug nuts).
The hub is attached to the spline (large nut).
Spline attached to the channel (weld).
Channel (axle) attached to the frame (several methods depending on suspension type).

Here's a photo(s)
http://www.boattrailerparts.com/Galvani ... p_861.html

Good luck.

[wingtime]

At each end of the square axle tube is a stub axle (sometimes called a axle spindle) similar to this one:



The stub axle is welded into the end of the hollow square axle tube.  As Marc mentioned it is this hollow axle tube that can in time rust from the inside out.  You'll never see it until it has started to rust through.  At that point it is time for a new axle assembly.

[Capt. Bob]

At each end of the square axle tube is a stub axle (sometimes called a axle spindle)

I knew it started with an "S".

[wingtime]

At each end of the square axle tube is a stub axle (sometimes called a axle spindle)

I knew it started with an "S".

Your description was good but I figured a pic would paint a clearer.....  picture  

[daniel123]

Thanks, guys. That really helps me wrap my head around what's going on down there.

Which leads to more questions:

Are radials really that much better, as they are for vehicles, for trailer tires too?

Can I make a single-axle trailer into a tandem just by adding a second axle assembly?

Dan

[wingtime]

How far do you tow?  Radials are best for those who tow far distances.  The sidewalls on bias tires are much stronger and are more resistant to sidewall damages, this includes rubbing the occasional curb etc.  I had radials on my last trailer.  They towed nice but as already mentioned the sidewalls bulged out MUCH more than a bias ply tire. Also when making a sharp turn (tandem wheels) the sidewalls pulled in and out very far due to the side loading caused when spinning the trailer.  I hated seeing that in the rear view mirror.  I was scared the radial tires were gong to pull off the rim! (it never happened).  I personally think the bias ply tires handle a overloaded trailer better than the radials.

Depending on how your trailer is built it could be possible to convert it to a tandem trailer.  You would need a set of four matched springs, equalizer, slipper style tandem spring hangers, U-bolts, shackles, fenders, hardware, and of course the axles.  oh yeah and tires and wheels.  With all of that it would probably just be cheaper to buy a used tandem and sell your current trailer.

[Capt. Bob]

I'll second the description on the radials (and the pic).

When I lived in S. Fla. I used the bias ply but switched to radials when I moved to the Forget Me coast. There (S Fla.) I was very close to the coast or kept my CCP in the water in the Keys so the trailer mileage was low but now....

I tow a decent distance to the closest ramp and make many a long haul so the radial is a good choice for me. They have a higher cost and as Wing stated, don't (IMHO also) stabilize a heavy load as well as the bias but....

They make for a very smooth ride (assuming your trailer is set up correctly) and wear well. Remember, it isn't the mileage factor but the time a tire sits on the trailer. Dry rot is the culprit. I tend to put a lot of miles (like Lewis) on my trailer so the radial makes sense. Knowing your boating habits helps.

Good luck.

[daniel123]

My boat is on the trailer all the time. I do one long haul from Ohio to the Keys or Pine Island each spring; other than that ten day trip the hauls are 20 miles round trip to the local lake once a month with the occasional 200 mile round-rip up to Lake Erie and back during our April-September season. I like to rig for that long haul to FLA, since it's our primary family-of-three vaca and a big deal trip for us that we'd hate to have interrupted with a breakdown. I'm glad to hear those Kenda's are ok for heavy loads (which it sounds like my 200 Osprey, on a single axle trailer, is?) as they are almost new and seem to tow fine --otehr than that cupping wear which I hope to remedy with a new axle. I actually bought three s of those tires so I'd have a matching spare. I have noticed very small hairline cracks on the sidewalls already...maybe I should get covers.

Dan