Scamp tire wear

[MyronL]

After 2 thousand plus miles of pulling the Scamp I parked it out back and forgot about it. Now, six months later, the trailer is back on my “to do” list. Cleaning out, tightening up, etc.

The tires! Couldn’t believe what I saw. But, before I go buy new tires I got to know what causes this kind of awful wear.

Could it be a worn out 3000 pound Scamp axle? Old axles make me nervous. Besides being rusty the torsion bar suspension doesn't look worn and crooked to me. But is it? Could it be wheel bearings, unbalanced rims? First instinct was to panic and replace everything under there. This is an ’86 and everything is screaming old, old, old. Yet, that formidable old Scamp axle is welded to the frame. Have not detected any cracks, twists, or whatever else might contribute to the issue. What did this? Tires are Carlisle ST 175/80D13 Sport Trail. About 6-7K miles on them I think.

My forum search was inconclusive. Do not want to fix what ain’t broke. Opinions anyone?

[Darwin Maring]

That is really bad. I would guess unbalanced and out of alignment but if it were me I would email the pictures to Dexter Axles and ask them. Get the answer straight from an axle company and take the guesswork out of it. Good luck and please post what U find out.

[Thomas G.]

Looks like balance issue to me. You may need an axle if there is no suspension travel left. A welded on axle can easily be removed and replaced.

[Darwin Maring]

The arm on our camper is angled down and yours are level. Look inside your wheel wells to see if the tires have rubbed up top side. It could be that the flex axle is worn out.

[Donna D.]

Humm, the tire is cupping. Cupping can be caused by an unbalanced tire condition, faulty wheel bearings, loose parts, or bad axle.

So, are the tires balanced? When was the last time the bearings had maintenance? Is this an original or replacement axle? (I see what you've written about the original axle).

I replaced a 20 year old axle in my 88 Scamp five years ago because it started eating tires. YMMV

[Byron Kinnaman]

The wear is on the outside of the tread, no wear in center. I would say under inflation is a probable cause.

[Brian B-P]

The arm angle means nothing about the state of the axle unless you know what it should be, which requires knowing the start angle. I would jack up one side and remove the wheel, then look at the arm where the square bar comes through - then I would see if the bar is permanently rotated and what the start angle is. Dexter Axle charts show the arm angle under full load, to be compared with the observed level attitude.

I described this several years ago in post #8 of When do drooping axles need a lift?, but since then it seems that most people seem more interested in wild guesses than actually seeing their axle configuration and condition. I don't know why.

As for the tires... sure, out of balance seems like a reasonable guess. Now that they are worn this way they presumably will be out of balance, even if they were not to start, making diagnosis less certain.

[David B.]

That is EXACTLY the look of our brand new & balanced tires about half way into our 2 month trip last summer. I placed the new spare to finish the trip, but it ate the tire the same way (bearings were fine and adjusted properly). My 1990 Scamp had the old style leading arm set-up, and I had the axle changed out to the current scamp style trailing arm set-up, but used a Flexi-ride axle. New tires again, and no unusual wear.
Good luck
Dave & Paula

[Byron Kinnaman]

Originally Posted by David B.

That is EXACTLY the look of our brand new & balanced tires about half way into our 2 month trip last summer. I placed the new spare to finish the trip, but it ate the tire the same way (bearings were fine and adjusted properly). My 1990 Scamp had the old style leading arm set-up, and I had the axle changed out to the current scamp style trailing arm set-up, but used a Flexi-ride axle. New tires again, and no unusual wear.
Good luck
Dave & Paula

Dave, I'm curious. Did you tire wear on outsides of the tread and leave the center alone. It looks that what happened the center seems to be normal wear or lack thereof. but the edges seem worn pretty bad.

[Carol H]

Myron as others have said lots of things can cause that type of wear. Did you have the wheel bearings checked and repacked prior to your trip? How old are the tires? Hard to tell on your small profile photo but the trailer looks to be riding a little low, which could indicate the axle is done. How much clearance do you have at the top of the tire to the wheel well?

[David B.]

Byron, I wish my memory would kick in as to exactly what the wear pattern was, but when I saw Myron's picture, my stomach reacted as it did when I discovered our ruined tire on our trip. From what I remember it looked exactly like Myron's picture. I believe that the worn leading axle design would allow the spindle/wheel to spread either out or inward, causing the scrubbing of the tire. Have you ever tried to push an oxygen tank caddy or a carry-on suitcase instead of pulling one? The forces of trying to keep a nice straight tac are tiring.
You can quickly see the advantage of a trailing arm system.

[Byron Kinnaman]

Originally Posted by David B.

Byron, I wish my memory would kick in as to exactly what the wear pattern was, but when I saw Myron's picture, my stomach reacted as it did when I discovered our ruined tire on our trip. From what I remember it looked exactly like Myron's picture. I believe that the worn leading axle design would allow the spindle/wheel to spread either out or inward, causing the scrubbing of the tire. Have you ever tried to push an oxygen tank caddy or a carry-on suitcase instead of pulling one? The forces of trying to keep a nice straight tac are tiring.
You can quickly see the advantage of a trailing arm system.

There's lots of unwanted forces in leading arm systems. Braking wants to lift the trailer, which I suppose could cause bouncing. The wear looks like under inflated and bouncing to me.

[MyronL]

This is interesting: I dug up the original Scamp owners guide. It provides general information on the trailer.

Under the sub-title "Running Gear- Axle":



"...the 16 foot and 5th wheel use a 3000 pound axle with 10 inch electric brakes. This type of configuration allows each spindle to operate independently of the other. Each spindle is set at 1/4 degree toe in, and 1/4 degree camber. Toe in and camber can eventually go out of adjustment, especially on curb side of vehicle...if unusual tire wear is noticed on one side of the tire this is usually the problem. Have axle checked at an alignment shop and corrected if necessary."

• Carol I thought it was riding a little low too, but picture indicates no clear evidence of issues in the wheel well. Was no play in the hub, suggesting the bearings are good. They were well packed.
• Brian with wheel removed everything with the axle is looking normal to me. But of course I have no idea what is normal here.
• Byron, Donna, Darwin, Thomas, David: along with Scamp's suggestion on axle allignment, wheel balance and underinflation is also looking to me like a prime perpetrator.

Guys, your input is very muchly appreciated. The wheels are off, I'm ordering new tires, and (damn!) seriously considering replacing the hubs and wheels, since they may not be involved in the problem but for some reason they are 4 bolt instead of 5 bolt.

I need a money tree.

[Carol H]

Myron, the bottom photo of your wheel well sure looks to me as if the tire has been rubbing on it. No idea if true or not but I was told when I got my old trailer to keep an eye on the tire clearance and make sure there was at least a full hand width of clearance at the top of the tire to the top of the wheel well as once that clearance is gone its time for a new axle.

[David B.]

Myron, if you do purchase new hubs, you can replace them with 5 lug bolt pattern, but you would need to purchase new wheels also. If you do purchase these items (either 4 or 5 bolt pattern) and this does not solve your tire wear problem, you can still reuse these items by just ordering a bare axle that fit your particulars. I had replaced our axle with a Flexi-ride and used our old hubs, bearings, brakes and wheels. This solved our problem and afforded me to be able to adjust our ride height in just 15 minutes.
Good luck.
Dave & Paula

[gmw photos]

My bet is the axle ( suspension ) is shot. Lack of a correctly working suspension, in this case, it's mostly bottomed out, is causing the tires to be slammed and overloaded every time you hit a bump.
How old is the axle ? If it's approaching or exceeding ten years old, the rubbers in it have likely perished.
Now having said that, I fully expect a legion of users to come along and say their ten year old torsion axle suspension is as good as new. Franchesca will be along shortly with her samurai dude to chase me off stage left.
All I am saying is I deal with various horse trailers, and I see a lot of them that are sacked out in ten years or less. YOur mileage and rubber thingies may vary.....
.... carry on folks.....

[Darwin Maring]

I got slamed for saying this: The arm on our camper is angled down and yours are level. Look inside your wheel wells to see if the tires have rubbed up top side. It could be that the flex axle is worn out.

Our camper arms are not level and there is room for them to flex up without hitting the wheel well.

The major thing is to see if the tire was rubing on the underside of the wheel well. I would speculate that a worn out axle would show some tire rub every time it hits a big bump.

[Carol H]

Originally Posted by Darwin Maring

The major thing is to see if the tire was rubing on the underside of the wheel well.

So am I the only one that can see rubbing marks on the wheel well in the photo posted by the OP????

[Carol H]

Originally Posted by gmw photos

How old is the axle ? If it's approaching or exceeding ten years old, the rubbers in it have likely perished.
Now having said that, I fully expect a legion of users to come along and say their ten year old torsion axle suspension is as good as new. Franchesca will be along shortly with her samurai dude to chase me off stage left.
.

looking at it I would guess its the original axle which based on the age of the trailer would make it about 27 years old. So might be safe from the samurai dude this time George - but I cant promise you!

[MyronL]

My axle shows no sign (old other welding scars, grind marks, etc.) it is other than an original factory install. However, Scamp's Owners Guide states, "3000 pound axle used on 16 foot with 10" brakes...etc " but goes on to claim a five bolt pattern whereas I got a 4 bolt pattern. Wonder if this is an indication of any significance.

Those black marks inside wheel well? If caused by a tire rub I can detect no actual sign of abrasion to the fiberglass skin like as if the tires were touching. Clearly, though, those black marks are rubber-ish.

I like the idea of buying a bare axle and re-using my brakes and hub, etc. but wonder if it is wise. Do I want to go and spend $600+ to fix the issue? No I do not. (Feeling kinda cornered .)