Max coupler

[cnynrat]

Ok I have another question. Which one do people think is better and y, max coupler or lock n roll?

Having some experience with both the Lock & Roll and the Max Coupler, here are my views on the tradeoffs between them:

1. I can confirm what Martyn said about the L&R binding when you back up with the trailer at an acute angle to the tow vehicle. I toasted my L&R on a trip in the Maze where that type of maneuver is pretty much unavoidable. There are pics in my trip report linked below.

2. The L&R is easier to get aligned when hooking up the trailer compared to the Max-C. Not a huge negative on the Max-C, but a definite difference

3. As mentioned, the Max-C has a zerk fitting to allow you to grease the coupler. My L&R did not, but I've seen pics of some that did have a zerk fitting on them. Perhaps some owners added that.

Since I usually only hook up the trailer once per trip, and I think backing is almost inevitable when towing a trailer on many trails, I give the nod to the Max Coupler.

 

[TacoDell]

This is a terrible design. Don't copy this one. Any rolling motion of the trailer results in the bolt thread turning in that welded nut. I expect it will wear out fairly quickly. Bolt threads are not designed for constant movement like that. I believe the Max Coupler has a bearing in there, as evidenced by the zerk fitting.

Not to mention that welded nut is... <shudder>

I believe SAE J684 is only intended for trailer manufacturers, not home-builders. That being said, if you have a problem with a stupid design, expect to get sued. Buying a coupler from a manufacturer allows you a large degree of protection, plausible deniability.

For SWAG off-road to build that coupler and SELL it to a customer is opening them up to a world of legal problems.

There's a big difference between what home builders can legally do, and what manufacturers/vendors can do.

yeah that thing, looks to be an attempted copy of the Max C.
but they got the 360* shaft all wrong
threading that shaft into a nut... is bad mo jo
and it's scary that they think it's good enough to pass on to others...

I wouldn't trust that homebrew hitch anywhere. ...ever

 

[Greenmonkey]

So I decided today that I'm going to go ahead and build my own coupler, not to sell but for my use only. I don't care if it's legal or not, I know it won't fail and I think it will be fun to see how it turns out. I will post pics when I'm finished. Thanks for all the good info and giving me a lot to think about.

 

[TacoDell]

So I decided today that I'm going to go ahead and build my own coupler, not to sell but for my use only. I don't care if it's legal or not, I know it won't fail and I think it will be fun to see how it turns out. I will post pics when I'm finished. Thanks for all the good info and giving me a lot to think about.

It's not illegal to copy anything... for personal use

If built correctly...
it can be every bit as solid as other certified products.
only difference in the end... is the liability

^ no biggie... if you know what yer doing.

I look forward to seeing yer finished product

 

[Swag Off Road]

I like the open discussion on this topic.

If I would have set out and build an off road trailer hitch from scratch I would most definitely do things differently. However I don't have plans to do so as I'm geared towards metal fabrication tools and Jeep related off road products.

FYI: has anyone seen the Pro comp and or Terflex adjustable arms on Jeep TJ's from 3 years ago. Both of them used a bolt and nut for their front lower control arms.

Troy

 

[Greenmonkey]

Ok, so remember this was my first attempt at this coupler. I already have plans for changes on the next pair, but for now I made two like this. No crazy alloys or anything for super strength but it will be plenty strong to tow the two off road trailers that I'm starting now. All comments are welcome.

This is the insert I welded in to the square tube.

This is the 1 1/4 shaft that will be machined and inserted in the square tube.

This is it finished with a uhmw washer to eliminate steel on steel wear. I've already been looking at stronger, longer lasting materials to replace them with. There is another uhmw washer in side the square tube with a large steel washer and a nut. This coupler is totally rebuildable, I don't know how long it will last but worse case I have to rebuild it.

This is the square tube with a greasable bronze bushing.

Finished product with a poly bushing and 5/8 hole from energy suspension. I am still working on the part that will bolt the the hitch of the rig. Remember this is my first attempt and I still have a lot to learn.

 

[HenryJ]

One thing that is easy to do and might add some "insurance" to your design?
The shaft you butt welded to the sleeve for the bushings. On mine that shaft extended through the sleeve for the urethane bushings. An enlarged hole through it allowed clearance for the pin to have some movement in the urethane bushings. The shaft was then welded to the front and back of that sleeve. The pin then has a back up retention and the sleeve a stronger weld. This still maintained the isolation of the bushings , but with the security of the pin passing directly through the shaft.

Just an idea. Keep up the good work. It looks great!

 

[TacoDell]

that's a better design then many of the home brew couplers I've seen

so it uses a double (jam) nut, that is accessed thru the back end of the sq. tube ?
Not sure how well a nut would wear on the welded insert cylinder surface...
but would guess you'll know soon enough.

The shaft's bushing (UHMW) don't make a lot of sense being located at the front outside of the sq. tube/insert end...
as a trailer's dead weight is primarily pulled... not pushed ('cept backing)
I'd think the bushing should to be on the inside and likely where your jam nuts reside... ( backside of the insert ? )

hope I'm not being too critical...
I think yer design ain't too shabby so far...
and I'd possibly roll yours, over most the other home brew couplers I've seen made.

Look forward to seeing the other piece of this puzzle...

 

[Greenmonkey]

It's hard to describe but here it goes. There is a lock nut with lock tight, a large steel washer, all tightened up against the shaft that runs through the steel insert. But there is a uhmw washer that goes around the shaft between the steel insert and the large washer. This way there is a uhmw wear surface when pulling(forward) or pushing(reverse) and a bronze bushing (2"long) pressed in to the steel insert. This way there is no steel on steel wear anywhere. I will try to get a better pic of it next week. Hope this helps

 

[TacoDell]

a single nut ? no lock washer ?
I don't know that I'd trust loctite alone wit' 'dat

smart of you to incorporate the umhw washers front and rear
but what exactly is this washer material... I'm not familiar

I've used bronze bushings before...
but not so sure I would trust them under a load... that gets jarred on occasion.
I think that bronze stuff would require too much maintenance

but hey... in time you'll know more

btw... nice work... if I didn't say

 

[HenryJ]

How about another idea to "safety" the nut that retains the shaft? I drilled my shaft behind the nut for a roll pin. A hole through the square tube large enough for the punch and it can be set and removed.
Should the nut fail or loosen this roll pin would retain the assembly.

 

['05TJLWBRUBY]

Having used UHMW in production facilities all over the plants for over 14 years in high wear areas specifically, I'd say it's wear resistance here in the case of this application should last a LONG time, longer than steel-steel type out there as well for sure. Even with a 3000 lbs. trailer being towed, there is nothing that trailer would see as far as wear stress like what we do with it at work. Even still, I do have some harder delrin type stuff here I think it is-it's the harder stuff similar to UHMW, some is dark grey, some is almost black. You're welcome to it if you want it, but it will need machined down to fit your bushing dimensions there. There's enough to do a TON of bushings though and I'd be happy to help if you like. I have a buddy outside of town offering some CNC equipment if need be.

Now, hurry home-Can't wait to test this thing! :smiley_drive:

Best of Luck,

Mike

 

[r_w]

The pinned collar HenryJ mentioned is how most farm equipment is made. If it really needs to be strong it is an extended collar with multiple pins. Never has threads cut on a shaft and use shim washers to adjust it for wear on rebuilds.

 

[Uglyduck]

Its been a few months now GR. How's this coupler doing? What would you change?

 

[Greenmonkey]

Well, unfortunately I'm still building my two trailer so I have not been able to try the couplers on the trailer yet. I was hoping to let someone try it out for me by now but they are not currently doing any overlanding with their trailer either. I wish I had someone to test it for me while I'm building my trailers. Sorry, I will let u know as soon as I can get miles on it.