Fold-Away Bolt-On Trailer Coupler

[mikeman]

Will I have issues using this steel Fold-Away couple on my aluminum trailer? Corrosion issues or anything?

https://www.princessauto.com/en/fold-away-bolt-on-trailer-coupler-hinge-kit/product/PA0008476459

logic tells me it wont work... so anyone know a solution for folding tongue on an aluminum trailer?

[nmpeter]

you could do a variable length tongue, the type that slides under or into the existing trailer setup. make it fully retractable and I think you;d make your space requirements.

heres a link

https://www.trailersauce.com/information/draw-bar-design/extendable-drawbar/

[K447]

Will I have issues using this steel Fold-Away couple on my aluminum trailer? Corrosion issues or anything?

https://www.princessauto.com/en/fold-away-bolt-on-trailer-coupler-hinge-kit/product/PA0008476459

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The photo image shows it to be a Fulton trailer tongue hinge.



I have used Fulton hinge for years on my aluminum Triton double PWC trailers, first was a single axle Triton Elite double and currently a modified double axle Triton WC2-2. I have also posted photos and info on using the Fulton tongue hinge.

I have not encountered any significant corrosion issues.

Is your aluminum trailer a Triton? PWC trailer?

http://greenhulk.net/showthread.php?t=291554&p=3147353&viewfull=1#post3147353

http://greenhulk.net/showthread.php?t=290011&p=3102655&viewfull=1#post3102655

http://greenhulk.net/showthread.php?t=283463&p=3050922&viewfull=1#post3050922

http://greenhulk.net/showthread.php?t=275496&p=2985032&viewfull=1#post2985032

http://greenhulk.net/showthread.php?t=274112&p=2973208&viewfull=1#post2973208

http://greenhulk.net/showthread.php?t=226268&p=2487702&viewfull=1#post2487702

[mikeman]

This is the feedback I was hoping to see, someone using it and being fine! Thank you.

I just bought a brand new seadoo and triton trailer so of course am wanting to make sure its all safe. turns out the trailer is a bit too long with the seadoo on it. This fix seems perfect!

I think with the zinc coating on the steel coupler should be fine.

also read this bit of information as well:
if the base material is a large sheet of aluminum, then using very small stainless steel screws will not dramatically decrease the life. Conversely, if you use aluminum to attach a large sheet of stainless steel, the aluminum life will be dramatically shortened.

[K447]

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I just bought a brand new seadoo and triton trailer -

Single PWC Triton trailer?
Which model Triton?

I have not looked closely at the tongue on a single PWC Triton, in terms of the wall thickness of the aluminum square tube. If it is the same thickness as the double Triton tongue then it should be just fine.

Do pay attention to the details.

Attach the tongue jack to the tongue/frame behind where you make the cut.

Extract/protect the trailer wiring during the metal cutting.

File the cut edges smooth and rounded before assembling the hinge to the trailer. I suggest sleeving the trailer wiring in convoluted plastic wire loom tubing to protect it where it goes through the hinge.

Plan where and how you will connect the safety chains to the frame of the trailer and to the hinged tongue. Chains must bolt to the trailer structure. On my own I ran the chains inside the tongue. Bolt through the tongue and chain inside near the coupler and another bolt farther back through the tongue stub. Plastic sheath on the chain where it goes through the hinge.

[mikeman]

I purchased LTWCI-X. And from watching YouTube videos and the advise you have given I agree with the recommendations and will be sure to use them. The frame is 2x3 so that's the Fulton couple I ordered. I could not find wall thickness so hope it's fine. Thanks for the info!

[mikeman]

Just viewing it online now Im confused it says 2x3 frame but wondering if the tongue part is in fact 3x3

[K447]

- the tongue part is in fact 3x3

A friend confirmed to me that the tongue on his single Triton PWC trailer (only a few years old model) is 3x3 aluminum.

[mikeman]

I appreciate you finding that out for me. It makes sense as that's the much more common size. I luckily was not only able to cancel my order on the 2x3 but ended up saving money and have ordered the 3x3! It all worked out luckily . Thanks again

[mikeman]

So ive got a response from one of the retailers and this is what they said : "Aluminum trailer frames have a greater wall thickness than a steel frame. The bolts that attach the hinge to the trailer frame have a large diameter shoulder which acts like a rivet, holding the parts together very tightly. Since an aluminum trailer frame has a greater wall thickness, the shoulder won't have contact all the way through the metal, resulting in a looser fit."

I just wanted to clarify that you do not have these said issues with yours?

[K447]

- "Aluminum trailer frames have a greater wall thickness than a steel frame. The bolts that attach the hinge to the trailer frame have a large diameter shoulder which acts like a rivet, holding the parts together very tightly.

Since an aluminum trailer frame has a greater wall thickness, the shoulder won't have contact all the way through the metal, resulting in a looser fit." -

This is technically correct, but I would describe it differently.



The portion of the bolt immediately under the head is smooth sided, without threads. The unthreaded portion fits through the hole in the hinge and then part way into the hole in the tongue material.



I have not precisely measured the extent to which the non-threaded portion extends into the tongue wall thickness. When the nut is tightened on the inside of a steel trailer tongue the bolt threads must allow the nut to fully clamp against the inner surface of the tongue wall without running into the non-threaded portion of the bolt.

So the smooth portion of the bolt does not (and should not) extend all the way through the tongue material thickness.

For the 3x3 coupler Fulton specifies

- material thickness between .188ÔÇØ and .120ÔÇØ

With an aluminum tongue the wall material is thicker (it must be, if it is going to have similar strength to a steel tongue), so there will be one or two more 'exposed' bolt threads between the tightened nut and the smooth portion of the Fulton supplied bolt.

The smooth sided portions of the bolts are there to 'pin' the hinge to the trailer tongue material, to resist sliding (horizontal pull/push) forces. If there was sufficient tension or compression force from the tongue to the hinge to overcome the clamped material friction and attempt to slide the tongue in or out of the hinge 'sleeve' the smooth sides of the bolt will transfer the force from the holes in the tongue to the holes in the coupler.

If there were threads all the way up to the bolt head, sideways forces would push the threads into the metal. The threads would allow a small amount of motion as the threads cut into the aluminum and the steel coupler hole sides mash against the threads. Over time the bolt threads would chew away at the aluminum holes, slowly enlarging them. And the bolt would become worn where the coupler was bearing on the threads.

The smooth sided portion of the bolt avoids this by having solid bolt material pressing against the inside sides of the holes.

In the case where we are 'adapting' the Fulton tongue hinge which is load rated for a steel tongue to use with an aluminum tongue, we need to recognize the differences. In my case I deliberately use a hinge coupler rated for a much heavier load than the actual trailer. My current Triton trailer weighs less than half of the weight rating of the installed hinge.

Here are the specifics for the 3x3ÔÇØ Fulton Fold-Away Coupler

https://www.fultonperformance.com/product/hdpb330101_trailer-tongue-bolt-on-hinge-kit

Note the load rating (based on a steel tongue) decreases as the 'tongue extension' becomes longer.

A swinging section that is 24ÔÇØ long is rated (steel tongue) for 5000 pounds of trailer.
With a 48ÔÇØ long movable portion the rating is half that (with a steel tongue).

24ÔÇØ to 36ÔÇØ seems to be a reasonable length for the swinging portion of the tongue on a small PWC trailer.
At 36ÔÇØ the Fulton 3x3 hinge is rated for 3500 pounds (with a steel tongue).

To maximize the strength of the installed coupler on an aluminum tongue you want to minimize the length of the foldable portion of the tongue. Measure for the shortest swinging section of tongue you can and still fit the trailer into your space.

My approach is to derate the Fulton coupler by at least 50% from the Fulton specs.
With a 36ÔÇØ long movable tongue section of 3x3 aluminum I would want the fully loaded trailer to be well under 3500/2=1750 pounds

A single Triton trailer weights about 200 pounds. The PWC might be roughly 1,000 pounds with fuel. So 1200+ pounds combined total weight.
1200 pounds is just over 1/3 of the Fulton coupler's weight rating (steel tongue rating) for 36ÔÇØ
If you can work with just 24ÔÇØ of tongue extension then the coupler is working at 25% of capacity.

Not only is the stress on the coupler reduced with shorter tongue swing lengths, the stress on the aluminum tongue material at the bolts is also reduced.


So yes, the smooth shaft portion of the Fulton supplied bolts is not engaging with the full thickness of the aluminum tongue material in each hole. It is engaging with a portion of that thickness.

My experience * has been that by greatly under stressing the Fulton hinge coupler the supplied bolts do not chew into sides of the aluminum tongue holes. It matters that the nuts be fully torqued so there is sufficient clamping force at each bolt to resist the sliding forces created during towing. Properly tightened into properly drilled holes in the aluminum tongue, the hinged coupler should not shift and slide on the tongue ends during use. The portion of the bolt shoulder that is engaged inside each aluminum hole seems sufficient to withstand the applied stresses.

There are sixteen bolts in the hinged coupler. Four on the top and four on the bottom, for each half of the coupler. That is a lot of clamping force and bolt 'side load' capacity.


* A story. When I had my second tongue extension installed using a Fulton coupler, I had a professional shop modify my new Triton WC2-2 double trailer. They added some aluminum decking forward of the winch towers and installed the Fulton hinge plus the tongue extension. This did make the trailer longer at the tongue by about 36ÔÇØ, which I knew would increase the stress on the coupler. The extension was also aluminum.

That modified WC2-2 trailer weighed maybe 2500 pounds with both skis.

There were multiple delays which resulted in the completed trailer being 'ready' literally the day before we departed on a road trip. The new trailer towed well, except that the surge brakes were repeatedly grabbing whenever we slowed down, jerking the trailer harshly. We drove about 600 miles the first day.

The next morning I noticed the tongue was 'sagging' at the hinge. I discovered the shop had installed all the bolts into the hinge coupler but they had not been torqued. The nuts were finger loose and the bolts were backing out and canted in the holes.

I decoupled the hitch, removed all weight from the tongue and spent some quality time with tools retightening all sixteen bolts to properly tight. I rechecked those bolts several more times during that 4000+ mile road trip. They did not re-loosen.

After thousands more trailer miles and a couple of years I removed that 3x3 Fulton coupler. The WC2-2 double trailer was further modified, and now has 3x5 tongue rail, 3x5 tongue extension and 3x5 Fulton hinge coupler.

I examined the removed 3x3 hinge and the places where it had been bolted to. There was no apparent wear on the aluminum, no evidence of sliding motion between the aluminum and the coupler sleeves. The bolt holes in the aluminum were still round. The bolts all looked good, no damage.

That was a 2500 pound trailer with 36ÔÇØ added to the aluminum tongue. Over 70% of the hinge weight rating. It was fine.



I think you will find a Triton single trailer with the same hinge (properly installed) should be strong enough.

[mikeman]

Well I don't think you missed a single thing. To say you have been helpful is an understatement. It has been exceptionally difficult to find details on this issue, people either say you simply can't do it, or that it's fine - but with no explanation. So I appreciate the time and thought you put into the response.

I would agree with everything you stated, 200 lb trailer, 1000 pwc with gas and storage.

I feel much more confident in the attachment now and know what to keep an eye on.

BTW that's a great set up you have, nice trailer !

[K447]

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BTW that's a great set up you have, nice trailer !

It now has a 3x5 tongue and reinforcement rails welded under the original WC2-2 structure. Strong enough to carry a third ski on bunks in between the trailer boxes.

[mikeman]

It now has a 3x5 tongue and reinforcement rails welded under the original WC2-2 structure. Strong enough to carry a third ski on bunks in between the trailer boxes.

That is awesome. I'd need a much bigger garage for that haha maybe one day. Glad the coupler holds strong.