How does this tire and axle look?

[Zennifer]

Trying to determine what's going on with our 1979 scamp; new to us this year. It needs new tires, but...does it need a new axle, or does it look like it's been replaced at some point? What could be causing this odd wear pattern?

[Zennifer]

Hers the front

[Zennifer]

The axle

[Zennifer]

The tire. Thanks!

[tractors1]

Looks like a bent spindle is causing wear on the one side due to the tire being tipped over a bit.

I'd replace the axle. Consider the down angle if you want to use bigger tires.

[Donna D.]

What is the born on date of the tires? What PSI does the tire say is the maximum PSI? What PSI is actually in the tire?

[Ian G.]

According to the Dexter engineers “Dexter would consider any Torflex arm that has moved more than ten degrees from the original build angle as weak or losing suspension”. But how would you know if your axle has sagged 10° or more when you don’t know what the start angle was?

The first test is to jack up each side of the trailer and watch to see if the wheel moves down as weight is removed from that side, if on either side the wheel does not drop at least 1½” the axle needs replacing. Second, measure the diameter of your tire (as an example ST175/80D13 trailer tires have a diameter of 24″) and divide this number by 2 (in this case 12″). Now with the trailer sitting on level ground measure the distance from the ground to the underside of the street side or drivers side frame rail as close to the axle as you can, either just ahead or behind the axle mounting brackets. Take the tire radius and subtract the frame to ground measurement, if the result is greater than 2½” your axle needs replacing (the above calculations are based on a fully loaded axle with an initial start angle of 0° to 10° up angle). Boler Rubber Torsion Axle - Boler-Camping

[ruscal]

I am not familiar with the suspension on 13' Scamps, but I know they are built lower than the 16s so they can fit into some garages. That said, the suspension arm may not angle down as much as a 16' which is in the area of 22 degrees. Yours looks to be angling UP about 20 degrees. If your axle is original to the trailer I would recommend replacing it. You could have smoother ride and new brakes. I could not see the tire wear in your photos due to the washed out light. Continuous wear along the inside of the tire would indicate a de-cambered (bent) spindle. Scalloping tread wear would indicate lack of suspension travel (worn out elastic in axle) causing the trailer to bounce. A new axle would make her sweet. And perhaps a new paint job to match the bug in your driveway!

[Zennifer]

Thanks! I was kind of hoping to just put new tires on an just kick the can 5 years down the road, but now I'm thinking I should take care of it.


If I go with 13" wheels again, but new 5 lug wheels, would my baby moons fin on them?

And how have people dealt with the spare tire not fitting on the mounts?

[gordon2]

Originally Posted by Zennifer

...

And how have people dealt with the spare tire not fitting on the mounts?

Trunk of tug.

[Johnny M]

Originally Posted by Ian G.

According to the Dexter engineers “Dexter would consider any Torflex arm that has moved more than ten degrees from the original build angle as weak or losing suspension”. But how would you know if your axle has sagged 10° or more when you don’t know what the start angle was?

The first test is to jack up each side of the trailer and watch to see if the wheel moves down as weight is removed from that side, if on either side the wheel does not drop at least 1½” the axle needs replacing. Second, measure the diameter of your tire (as an example ST175/80D13 trailer tires have a diameter of 24″) and divide this number by 2 (in this case 12″). Now with the trailer sitting on level ground measure the distance from the ground to the underside of the street side or drivers side frame rail as close to the axle as you can, either just ahead or behind the axle mounting brackets. Take the tire radius and subtract the frame to ground measurement, if the result is greater than 2½” your axle needs replacing (the above calculations are based on a fully loaded axle with an initial start angle of 0° to 10° up angle). Boler Rubber Torsion Axle - Boler-Camping

Great info Ian! I want to raise the height of mine and thought about a leaf spring axle any thoughts on that?

[Zennifer]

Originally Posted by gordon2

Trunk of tug.

Maybe...but it's a minivan and often packed to the gills anyway with two kids and a dog plus bikes and the stuff that doesn't fit in the camper! I'd love to figure a way to keep it on the rear of possible..

[floyd]

Originally Posted by ruscal

I am not familiar with the suspension on 13' Scamps, but I know they are built lower than the 16s so they can fit into some garages. That said, the suspension arm may not angle down as much as a 16' which is in the area of 22 degrees. Yours looks to be angling UP about 20 degrees. If your axle is original to the trailer I would recommend replacing it. You could have smoother ride and new brakes. I could not see the tire wear in your photos due to the washed out light. Continuous wear along the inside of the tire would indicate a de-cambered (bent) spindle. Scalloping tread wear would indicate lack of suspension travel (worn out elastic in axle) causing the trailer to bounce. A new axle would make her sweet. And perhaps a new paint job to match the bug in your driveway!

Up 22 dgrees is OEM on Scamp 13s. Negative camber is the result of rubber fatigue(normal wear over time). A spindle is much more likely to break than bend, and in the unlikely event it did bend,it wouldn't roll much more than out of sight.
The photos aren't clear but they don'tseem to show inside edge wear, but there might be wear on the second tread in from the outside which is common on straight axles with bias tires. plus the tires do appear to be superannuated and weather worn.
Better pictures please, but from what can be seen, I'd say new tires, then monitor tire wear over the next few years.

[Zennifer]

New tires are DEFINITELY on the plans. TBH, I only trusted them the 7 miles from where I bought it to my house (I know-how lucky was THAT!) at slower speeds on the side roads. They look OLD and worn out.

Thanks for the look everyone-I still need to do Ian's test, too. and then weigh everything. And see if anyone can get us taken care of on a new axle before our first trip in 3 weeks. That may determine it...

[ruscal]

I had to deal with changing the lug pattern on the spare tire, but I can't recall what I did. There were some all thread studs that protruded through the shell. I suppose you could just redrill as necessary, and patch the old holes. There is some wood structure inside that supplies support. Alternately you could bolt a flange to the existing studs with a short tube welded to it and a flange to fit the new wheel lug pattern welded to the tube. That would be more costly, but eliminate the holes to patch.
Russ

[ruscal]

Originally Posted by floyd

Up 22 dgrees is OEM on Scamp 13s. Negative camber is the result of rubber fatigue(normal wear over time). A spindle is much more likely to break than bend, and in the unlikely event it did bend,it wouldn't roll much more than out of sight..

???
I was using the term "spindle" to mean the control arm/axle assembly. I speculated that an axle that had worn out rubber would ride harshly and not absorb bumps. The combination of worn out axle encountering a pot hole would bend the control arm decambering it. Most metal will bend before breaking unless is is glass hard or a casting. I assume the control arm is a forging, not a casting, so could bend.
If the torsion bars are not supported at the center of the axle, the tips would sag as the rubber elastomers age allowing some decambering that the outer bushings could not resist due to leverage. That is probably what you speak of. Bushings at the center could stop the decambering effect of rubber wear, but the axle is probably done in by then anyway!
Russ

I've been informed there are no bushings, just rubber. That would explain plenty of decambering with rubber aging!