Ot- Is there a visible camber change on dual torsion axle trailers when you back?

Some friends just bought a sort of mid level RV a 5500 pounds or so, dual torsion axles and set with a sway bar rig on tow vehicle.

I was working with them as they tried to learn how to back the rig in a parking lot and wow the front and rear axle were out of alignment.
Really weird- looked like extreme positive camber on right front wheel and less so on left.

What’s up.
Is backing loading the rear axle enough to relieve the load n front pair and make the unloaded pair change camber?
Or both sets change load enough to make them look way out.
I’m talking like 2” difference.

I started grabbing the tire and giving it a shake to see if the lug nuts were loose or the bearing play way out.
What’s the deal- optical illusion?
I followed them to the parking lot and all looks fine while moving forward.

Thanks

Trboatworks said:

Some friends just bought a sort of mid level RV a 5500 pounds or so, dual torsion axles and set with a sway bar rig on a Suburban as tow vehicle.

I was working with them as they tried to learn how to back the rig in a parking lot and wow the front and rear axle were out of alignment.
Really weird- looked like extreme positive camber on right front wheel and less so on left.

What’s up.
Is backing loading the rear axle enough to relieve the load n front pair and make the unloaded pair change camber?
Or both sets change load enough to make them look way out.
I’m talking like 2” difference.

I started grabbing the tire and giving it a shake to see if the lug nuts were loose or the bearing play way out.
What’s the deal- optical illusion?
I followed them to the parking lot and all looks fine while moving forward.

Thanks

Click to expand...

That’s normal, the trailer will pivot on one set of axles and scrub the other depending on how it’s configured?
You should see a triple axle, it pivots on the center and the other two axles scrub in opposite directions!

Kevin

A loaded trailer should have zero camber. Many cargo trailers have a bent axle so under load they go from positive to zero camber. The spindles may be bent.
Or do you mean on the tow vehicle axles?
Bill D

Bill D said:

A loaded trailer should have zero camber. Many cargo trailers have a bent axle so under load they go from positive to zero camber. The spindles may be bent.
Or do you mean on the tow vesicle axles?
Bill D

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TORSION AXLE…..

I'm not sure how you would tell the difference, but there are cheap shit torsion axles and there are decent ones.

A good friend has an equipment trailer with dual 8 lug torsion axles. It will try to kill you with any weight on it. Sketchiest thing I have ever towed. Like there's a monkey with a steering wheel slamming left-right. I have tow-bar towed a city bus down a mountain pass with an F-250 and that trailer is worse than that. One of my heavier trailers has dual torsion axles. I have had 20K on that trailer and it does fine. It usually hauls an 11k excavator.

Given the option, I will choose slipper springs on any small trailer.

I am buying the scrub explanation as the trailer pivoted.
It just was surprising to watch- WAY out of camber..
I guess they were 15” tires, alloy wheels.
It seems odd but something was happening.

I yanked the tires around a bit and didn’t feel any obvious give.
Did not go so far as toss up on a jack and check.
It’s a brand new rig and seemed like the delivery was a bit rushed.
I guess I went into it wondering if everything got set up correctly at plant.
The trailer belongs to some friends of mine.

I yanked the tires around a bit and didn’t feel any obvious give.
Did not go so far as toss up on a jack and check.

Do you seriously think you can grab a wheel on a tandem axle travel trailer sitting fully weighted, and “yank it around”? Seriously? SMH!

Dieseldoc said:

I yanked the tires around a bit and didn’t feel any obvious give.
Did not go so far as toss up on a jack and check.

Do you seriously think you can grab a wheel on a tandem axle travel trailer sitting fully weighted, and “yank it around”? Seriously? SMH!

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Yeah I actually do- it’s just ~1400 pounds on each tire and believe it or not you can get a good feel for how solid something is attached by a decent kick or grabbing the tire and giving it a decent shake.
But I’ve been working in shops all my life and have good sense.
I can’t speak for everyone.

Normal. Two axles, different circles.
Never owed a car with 14 inch wide tires and a spool? Same deal.
Something gives up in the turn.
It does look like something is coming apart or oh so wrong and you do the whole oh-shit thing.
It's just wind up. Mostly only see on clean pavement as in dirt the tire will skid and give up first.
As a boat guy I'm surprised you have not seen this when someone wiggle wabbles a trailer in.
First time I saw it I was, holy poop, that wheel is coming off that trailer, this is going to be bad. I'm gonna run.
Watching it wind up and twist top to bottom seems all so wrong to everything your mind says.

Me too on the decent kick or hard shake even when loaded.
Bob

Yeah Bob now that you mention it yes- scuffing and popping gravel as some newbie tries to back a boat trailer.
I just never remember seeing the whole rim laying over.
Maybe the torsion liners in the axle tube yielding.
The damn tube itself?
These travel trailers are pretty light built deals.
And yep- on clean dry pavement with brand new tires.
And the guy driving was fighting it- jack knifing the rig- halts and starts as he tried to get a feel for backing her down.

Thanks guys- that seems to answer it.

Sort of off topic but since mentioned.
Never ran a sway bar or this sort on a 5-6000 pound trailer.
Not even at 12,000+ pounds from Michigan to Florida.
Does it work? Do the fancy hitches and bars help?
Yes I know a fifth wheel miles different deal but the fancy trailer hitches why?
Bob

I told them not to bother- I just balance the tongue weight to 10% and figure if the tow has enough balls to not squat not heeded.
This was yet another case where I got overruled by the dealer and youtube. The extra kit was 4K from dealer on a 16k trailer so a big bump up on price of rig.
You tube sort of scares people into these things- the “it saved my life” stories...
To me it looks like a complicated pain in the ass and this kit creates a pinch point where the rig first contact on a jackknife is right on the welded bail and first two links of safety chain on the tongue.
And the rig jackknives way too early...
With that one I just kept my mouth shut and hope the bail bends out of the way and doesn’t get torn off..

After a couple of rounds of I can fix this/weld that etc met with calls to the dealer and panics about voiding warranty I have just backed away and figure they are on their own.
And the stories from them about the quality of help from the dealer... whew.
Last night there was another one where the tongue jack the dealer provided did not fit the rig and the SUV back hatch can’t open- I told them I could yank the jack tonight and take it into the shop to modify and weld up so it works.
You know- on my dime- just to get them going.
The eyes go wide- the calls to dealer who I know are clueless MF’s....

The way I see it the move it down the road feeding chain is from top to bottom - aviation, yachts/marine, automotive and in far last place RV’s

A couple of our friends have gotten into this trap- mechanically clueless and arms tied by “it will void the warranty” trap.

It is NOT in my nature- I buy good gear and once I buy it it’s mine- if I want to cut into it to set things to right I am damn well going to.

Yachts are like this in a big way- basically two types of clients - those tied to a repair network to keep them going and the skippers who will beach the boat at low tide to patch the hull or tear down the engine themselves to replace a thrown bearing at the ends of the earth.

The second type sail to the ends of the earth and when they roll into town it’s for beans and beer and a extra set of bearings for the pumps in case they need them out there. The first come back from a weekend sail with a list of things needing done to keep me employed...

Ok rant over- they will be fine and have fun with this rig.
It’s just a whole different world from how mechanical types go about business.

Of course I am building a camper from scratch in the shop right now and the damn thing is still not done so there is that.
And I live in a piece of shit falling down house I don’t have time or money to fix while the less mechanical sorts make enough coin to just pay for the work so there is that..

There is something to be said for buying the damn gear and getting on with life.
But my trailer design is a cool piece of kit and no one makes one like it and that’s what I do- design and fabrication work...

I like sailing and camping and welcome everyone to get out there.
Different folk/different ways to go about things is the way of the world..

Trboatworks said:

I am buying the scrub explanation as the trailer pivoted.
It just was surprising to watch- WAY out of camber..
I guess they were 15” tires, alloy wheels.
It seems odd but something was happening.

I yanked the tires around a bit and didn’t feel any obvious give.
Did not go so far as toss up on a jack and check.
It’s a brand new rig and seemed like the delivery was a bit rushed.
I guess I went into it wondering if everything got set up correctly at plant.
The trailer belongs to some friends of mine.

Click to expand...

Was this the torsion boxes set up ? the kind with no axle ?

No- cross square axle which looks sort of light weight- has a uneven beat up looking camber bent into it.
I am assuming the stubs/cords are short on each side.
I don’t know if they use the Dexter axles or not.
It was some crazy shit- I’ve never seen wheels lay over this far.
The cords on the torsion boxes must be crushing and even that doesn’t seem like enough to allow the wheels to fold over this far.

I'm wondering if the manuf didn't align the axles right. Reading in trailerLife Mag. I see this has happened many times.

Backing a boat trailer....well sometimes with any trailer, you need to crank it around tight (I love gooseneck trailers for this reason)
Used to sit down at the Niagara pier with my uncle and watch the boat trailer backing (a spectator sport for sure).

Don't put wife out back to holler directions. Always have "helper" get in your mirror, and use hand signals. And agree on which "right & Left" you are working with...yours, hers, the car's, or the boat's.

The arguments we saw going on were hilarious.

My uncle, a truck driver, finally went over and got in one of the newbies vehicles and plopped the boat
right where it should go. There was a line of angry boaters waiting for ramp access, was gonna get ugly
in short order.
Google Maps
We used to sit right where that white boat & truck is sitting, bottom of pix.

Yep- some of the scenes dockside are grim- I’ve watched plenty of bloody yelling matches and boats being driven up into docks or into the cockpits of other yachts- the helmsman in full panic and wow.


It seem like the brain disconnects- they realize there are no brakes so slam the throttle forward- weird..

I bought our first big boat up in Maine.
We immediately did a down East cruise and the first time I had to get on a fuel dock was grim.

Took about five tries to lay along side into a strong ebb.
Old codger was standing on the dock- “eh you coming today”.
I yelled back to just wait I’d get there..

These days a midships spring handed calmly off the bow, let her blow off and soft forward steering the prop wash with the rudder to kiss the dock beam on neat as can be into a full gale or a 6 knot ebb.

Ya learn things.. hopefully.

Trboatworks said:

...believe it or not you can get a good feel for how solid something is attached by a decent kick or grabbing the tire and giving it a decent shake.
....

Click to expand...

What would you have done if the wheel just popped off in your hand? Sorta like the dog chasing the car, what would he do with it if he caught it?

jim rozen said:

What would you have done if the wheel just popped off in your hand? Sorta like the dog chasing the car, what would he do with it if he caught it?

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Well I’d probably tell the owners it wasn’t needed anyway.
Just carry on..

jim rozen said:

What would you have done if the wheel just popped off in your hand? Sorta like the dog chasing the car, what would he do with it if he caught it?

Click to expand...

Much better to find out right there & then, standing still.

Or you would rather like that wheel coming at you at 80 mph whilst out on your motorbike ?

I was following a couple of codgers driving a pair of matching little campers with alloy wheels.
The must have just bought the damn things.
So we crossed a repair area where there was a standing seam in the asphalt running off at an angle as a lane shift ran past the repair site.

Damn If both of those little trailers didn’t both shed a wheel which put them both on their hubs and what was left of the tire/wheels went running off the road.

Weird- little shitty 13” alloy wheels .

I also had a friend toss a wheel he had forgotten to tighten the lugs on which also went running off down the road.
That’s what I had figured here- the dealer didn’t tighten the nuts..

The world is full of idiots— you have to be careful out there.
I have first hand knowledge- I’m one of them..