Scamp tire wear

[gmw photos]

I reckon some these kinds of issues are a good news/bad news kind of situation. You all have these FG trailers, and like Airstream trailers, they seem to last a good long time. That's of course the good news. The bad news is there are going to be some consumables, like suspension parts, that are simply going to have to be replaced occasionally.
My little stickie I'm sitting in right now, will probably fall apart before the suspension gives up the ghost. So there we go, life is full of tradeoffs.
In your case Myron, I would just go ahead and buy a new axle, complete with new brakes, get some new wheels and tires, and plan on enjoying the heck out of this little jewel for a whole bunch more years. And even if you end up selling it in a few years, the new components will be a definite selling point, no doubt resulting in a higher selling price.

[Carol H]

Originally Posted by Myron Leski

. 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.

Is the manual you got that from the original with the trailer or the one Scamp has on line now? Scamp has made some changes to axles and hubs used over the years I know my 92 has a 5 bolt pattern but looking through older photos of some 80's 16' trailers it appears they may only had a 4.

Based on the age of the trailer I would say if you need a new axle your best to replace the hub and brakes as well. I replaced the hub and brakes on mine a few years ago due to their over all condition even though the axle was/is not bad enough to need replacing yet....

[RogerDat]

With the tires on and trailer hitched to TV have someone bounce on back bumper while you watch the hub, axel and tire.


You will see tire hub moving up and down and how much OR you will see nothing but tire wall flex because the rubber is so shot you have no suspension.


If you step on the back bumper without hitching to TV the trailer will probably try to "stand up" on it's hind legs. Don't ask how I know.

Hard to tell but that cupping looks pretty even. Not sure if suspension bounce cupping would be that evenly spaced. As Byron pointed out low inflation can cause cupping because tire "wiggles" as it goes down the road, wiggles tend to be even.

How old are the tires? Age can cause hidden breakdown of inner ply that can lead to tire wiggle and cupping. Tires are typically only good for 4 or 5 years no matter what the tread wear.

Dog tracking where trailer tows straight but offset a little to one side can cause cupping, tire will tend to scuff on curves and corners. Having someone follow behind is easiest way to spot that. So called because some dogs run with back end moved sideways to keep rear legs from running into front legs.

And one really odd thought - do you have a 1 7/8 inch trailer hitch on a 2 inch ball? Hitch might go on but be too tight and so drag the trailer tires on curves. I have trailers with both and have hooked up small hitch on bigger ball. Felt wrong latching so I caught it but am pretty sure I could have continued if I had used a little more force to latch. And 2 inch is more common size.

[MyronL]

I honestly don't know where I got that owners manual-- cannot find an original copy and do not have a cover sheet, which tells me I must have downloaded from Scamp and printed seleced pages. I noticed other discrepancies, like their listed wheel bearing part number was different from what fit in the hub when I changed the bearings.

[GMike A]

I had that on my car once and it was because the wheel was being gouged by the fender well. Looks just like that.

[RogerDat]

Originally Posted by GMike A

I had that on my car once and it was because the wheel was being gouged by the fender well. Looks just like that.

I have seen fender/wheel well rubbing as you describe cause that type of wear on a car also. I would have expected more damage to the FG wheel well for the amount of tire wear I think I see in that picture. But as someone else pointed out if it's hitting top of well at all it's probably too bouncy from shot rubber in axel.

One nice thing about replacing the axel, if you are willing to replace hubs you can use larger tires if you order axel with enough down angle. Get some additional height. and decide how stiff you want the suspension to be. Still pretty good chunk of money, I would want to bounce test before spending it. Improve the odds the expense would fix the problem.

[Donna D.]

Myron, my 1988 had an Alko axle with four stud wheels. It died, it was eating tires... replaced it with a 3,500 lb axle, five stud 4x5.5 wheels.

[Eddie Longest]

Myron
In the 80's Scamp was installing 2.2K axles on Scamp 16's. They have 4 lugs, 7" brakes and (I think one inch) straight spindles. The 3500# axles have a stepped spindle with 10" brakes and drums. Like the PIC. If you had a Dexter axel you could verify what you had with Dexter from the data tag. You won't be able to use your current equipment with a new 3.5K stub axle if yours is a 2.2K axle.
All the dead 2.2K axles on S-16 I have seen are like yours in the 0 degree position. With a new axel you can order it with ez lube hubs, and a 2" rise and bolt on brackets so when you replace it 25 years from now you can just bolt on the new axle.
Eddie
You can order which bolt pattern you want.

[MyronL]

Yep. Them are 7-inch brakes on my Scamp. Eddie, Donna, I think you just cleared up the muddy waters in my mind. Looks like my best move is a new axle.

[Roy in TO]

What information does the Al-Ko tag provide on the axle? Can you upload a close up of that? The Al-Ko is a little different from other axles I've see and can't come close to guessing what the original angle may have been from your picture.

What is the range of motion on your axle? Jack up your trailer so one wheel is off the ground. Pick a spot on the torsion arm and measure it to a marked spot on the wheel well on one side. Do the same with the trailer on the ground bearing its own weight. Add 4-500 Lbs weight to that side and measure again. Repeat for the other side. Compare your numbers and post them.
That will give you a range of motion of the "torsion" part of the axle and not tire flex.

[MyronL]

3500 lb. Flexride torsion axle with electric drum brakes: $519 + $73 shipping.
2 ea ST175/80D13 tires with 5-lug wheels: $126 + $40 shipping.
Backyard labor with beer and sandwiches: free
Medical attention: bandaids, linement, more beer

Piece of brain-- I mean mind-- priceless.

[Brian B-P]

Originally Posted by Myron Leski

• Brian with wheel removed everything with the axle is looking normal to me. But of course I have no idea what is normal here.

Okay, I was foolishly assuming a Dexter Torflex; if it were a Torflex, I would gladly work through the visual assessment. Unfortunately for this purpose, it's not a Torflex. It is probably an Al-Ko; there's nothing wrong with that, but the round cap covers the part which would allow determination of the start angle on a Torflex.

Sorry for the confusion.

Originally Posted by Darwin Maring

I got slamed for saying this: The arm on our camper is angled down and yours are level...

I certainly didn't intend to "slam" anyone, but since start angles vary from year to year or just at the whim of the builders, a comparison of arm angles without knowing that they started the same just isn't useful.

Originally Posted by Roy in TO

The Al-Ko is a little different from other axles I've see and can't come close to guessing what the original angle may have been from your picture.

Neither can I. Again, sorry for the confusion. If anyone does have a way to determine the start angle of an Al-Ko (is the bar end visible if that round cap is removed?) please share it.

[Jared J]

My wheel well clearance didn't change at all when I jacked up my scamp 19', it was pretty obvious the old 2200 pound axle was shot.

With the new 3500 pound axle, you can see it squat a bit when the jack goes down.

[MyronL]

[QUOTE=Jared J;393251]My wheel well clearance didn't change at all when I jacked up my scamp 19', it was pretty obvious the old 2200 pound axle was shot.

Jared, can you elaborate? I really need to know what "pretty obvious" means. With my '86 2200 lb axle nothing seems amiss at all to me. Looking at my pictures, can you detect anything? I see no twisting, no bleeding, no popped open seams, no squeezed out rubber grommets or washers, no loose nuts - in fact - I see nothing looking out of allignment or even at all adjustable. I'll take more pictures if necessary.

I just got back from the city where I had 2 new tires mounted on my old rims, which were then also balanced. The guy said he thought my kind of wear would likely be caused by unbalanced rims, and/or underinflation, or both. This same opinion was also offered by the trailer axle shop owner I spoke with today. By the way, axle-guy also volunteered his low opinion of torsion axles compared to ones employing springs. Said they don't last as long.


Well, the fun just never ends.

• I also went to two trailer parts suppliers in town, looking for replacement brake pads, 7-inch. Nobody has them!
• I measured the outside width of my frame at 47½ inches, and Scamp claims their 3500 lb. replacement axle with 10" brakes is 49 3/4 inches for a 19-footer.

[RogerDat]

[QUOTE=Myron Leski;393440]

Originally Posted by Jared J

... I see no twisting, no bleeding, no popped open seams, no squeezed out rubber grommets or washers, no loose nuts - in fact - I see nothing looking out of allignment or even at all adjustable. I'll take more pictures if necessary....

...By the way, axle-guy also volunteered his low opinion of torsion axles compared to ones employing springs. Said they don't last as long....

Torsion axle they insert rubber bar into hollow axle by freezing to the point it contracts and becomes hard, then slide it in with arm and hub spindle attached. Once rubber expands it's locked in place. Nothing to leak, or grommets, or washers or adjustments.

The only "adjustment" is done when it is manufactured, and that is what angle the arm with the hub spindle is connected to the rubber in the axle at, or down angle.

0 degree down angle would be spindle straight back and level with axle, 10 degree would be spindle just slightly below axle, on through 22.5 and 45 degree down angle. Down angle is the angle of the line between the axle center and the hub spindle center as measured against level with axle center.

Suspension action normally provided by springs and shocks in "regular" axle is provided by the fact that pushing up the hub causes the rubber in the axle to be twisted, the further it gets twisted the more tension rubber is under so the more it resists tire being pushed up. Keeping the tire pressed firmly on the road when going over bumps while cushioning the trailer from the bumps.

Your spindle looks like it is very close to 0 degree down angle in those pictures, if it was originally 10 degree down angle, being 0 now would mean the rubber has lost a lot of elasticity. Trailer weight is enough to push tire up, trailer rides low, and going over bumps the tire bounces off the road because the rubber can no longer apply the force to hold it down.

But no one knows what original down angle was on your trailer, could have been only 5 degree or even 0 degree when manufactured. That stuff changed a lot over the years.

As to spring axle lasting longer... well yes steel leaf spring would BUT if you ever watched a lightly loaded utility trailer bouncing down the road like a rubber ball you know why high end campers such as Airstream used torsion axles. Empty or fully loaded torsion axle provides smooth suspension.

That and torsion axle provides the ride and suspension of springs plus shocks without putting the trailer an extra foot or more off the ground. Or having to find some weird sized shock absorber when they wear out.

I should note since if I don't someone else will there is an after market axle that does allow adjusting down angle, that one would have adjustments.

Reason axle is suspect for tire wear is if rubber is shot it allows tire to bounce off of the road when tire slams back into road there will be scuff wear and/or cupping. But someone noted your cupping is mostly at the edges, underinflated tire arches in the middle so center is not making contact with the road.

[Eddie Longest]

Myron
The brackets on a #10 (3500#) Dexter is 2.5" wide and the #9 axles are 2" wide. When you order an axle your bracket spacing is is based on outside spacing of the brackets. Scamp frame rails are only 1.5" wide. So your #10 axle over hangs the frame by 1" on each side. You want to your axle brackets to line up (almost) on the inside of the of the frame rails. So measure your inside frame spacing the add 5" and you get the apprpoximate bracket spacing. You can't weld the axel bracket to the inside edge of the frame rail because the floor support angle is welded to the edge of the frame. Scamp spreads the axle brackets so the axle bracket is welded to the bottom of the frame not exactly to the edge of the frame rail. That is why the axle brackets are slightly wider than the inside of the frame.
Now you get to the axle alert issue with the 1" gap from the outer edge of the frame rail to the outer edge of axle bracket support. Some weld 1" square stock to the frame rail outer side to the edge of the outer axel support. On the last axel I replaced Scamp used 1" angle iron to provide the support which worked OK. This support should be welded to the frame prior to the axle install so the bottom of the support can be welded to the lower outer edge of the frame rail.
One more note: If you add the bolt on brackets to your axle you also have to add for their thickness.
I'm sure this adds a little more confusion, but that's why the numbers don't seem to add up. Just measure the inside spacing of your current axle and add 5" and you should have your replacement axle bracket spacing.
Eddie

[MyronL]

Roy, Roger, I very much appreciate your detailed and learnéd description of how these axles (should) work. So um...therefore, the only physical proof the axle is shot is rubber marks inside the wheel well and - "eaten" tires?

I will install my new tires and tow the trailer to nearest big, flat, paved parking area, where I will perform bounce tests to see what happens in the well.

[Carol H]

Originally Posted by Myron Leski

Roy, Roger, I very much appreciate your detailed and learnéd description of how these axles (should) work. So um...therefore, the only physical proof the axle is shot is rubber marks inside the wheel well and - "eaten" tires?

I will install my new tires and tow the trailer to nearest big, flat, paved parking area, where I will perform bounce tests to see what happens in the well.

If I was you I would do the test first. If you get a new axle (& it sure sounds and looks like you need one) you will need new wheels and with those come different tire sizes. Would be a waste of money to buy new tires to fit old wheels you will not be able to use on the new axle.

As far as no physical proof the axle is shoot other than the tire marks on the wheel well and the tire wear which are two big ones, more than a few people have mentioned your profile photo shows a trailer riding pretty low which in itself could also be taken as physical proof of a shot axle.

[Carol H]

Originally Posted by Myron Leski

I honestly don't know where I got that owners manual-- cannot find an original copy and do not have a cover sheet, which tells me I must have downloaded from Scamp and printed seleced pages. I noticed other discrepancies, like their listed wheel bearing part number was different from what fit in the hub when I changed the bearings.

Myron I would suggest you either downloaded the manual from Scamp or from the Document center on this site. Unfortunately the information contained in it applies to somewhat newer Scamps than yours that have different axles, hubs and bearings.

[Jared J]

What I meant was, if you jack up the axle and the tire doesn't move in comparison to your wheel well, the axle is shot.

Here's how mine started with 175-80/13 tires.



The axle was angled up, and didn't move when jacked up.



New axle, 3" frame lift, 225/75/15 tires.