Lunette ring......

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Degnol

Degnol

Joined
Jan 22, 2003
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I am going to build a 416-style trailer and want to use the pintle/lunette type hitch. Sourcing a lunette there are at least two swiveling styles, one short with a threaded end and a castle nut/cotter. The other is longer (like the 416) with a spring, threaded end/cotter. There is a huge difference in cost, like $40 versus $140. How important is the spring? I think I would be fine without one, but thought I'd ask anyway.

Ed:confused:
 
The spring setup is quite useful in giving the trailer dynamic stability. There is the ability to articulate; however, the spring attempts to keep the trailer coming back to alignment (rotationally speaking) with the tow vehicle. Very useful.
 
dieseldog said:
The spring setup is quite useful in giving the trailer dynamic stability. There is the ability to articulate; however, the spring attempts to keep the trailer coming back to alignment (rotationally speaking) with the tow vehicle. Very useful.
Click to expand...

Does it have some rotational force? Other than creating a little friction and maybe acting like a shock absorber on starts, I don't understand how it would keep the trailer upright. :confused:

Ed
 
the springs are typically just a shock "absorber" of sorts to prevent big clunking when braking, I believe. Well, at least the ones I've seen.
 
That's what I thought, but Dieseldogs reply had me confused, which is not difficult to do;)
OK, I'm goin' on the cheap and leave out the spring option. I'll just watch those burn out starts.

Ed
 
i thought they were shock absorbing too. the only way I can see them having a rotational effect is if there are two of them, with each allowing rotation under tension in each direction but wanting to snap back to 12 o'clock. I don't see that on the set up i've seen.

dieseldog talking to degnol on a thread is also confusing due to their avatars belnding together ;)
 
semlin said:
dieseldog talking to degnol on a thread is also confusing due to their avatars belnding together ;)
Click to expand...


I never saw that! But you're right.:)


Ed
 
check ebay, I got mine there, a setup cut off some big trailer...
 
Well, there is an outfit that sells used 416 parts, and the ring alone is $100, the spring and nut are offered separately for more $$. I called a local trailer outfit here in KC and was quoted $140 for the whole shebang. The short ones are online, ebay stores, for about $40. That is why I asked about the importance of the spring. Think I'll do without. The short one still swivels.

Ed
 
Dieseldog is talking about setups that have a camming surface and pin through the shaft of the lunette ring. The cam surface has it's low points at top and botom (could be left and right, I guess) and the spring pushes the crosspin into the cam surface causing it to index at vertical and keeping the ring horizontal by the spring pressure. This is easier to visualize than to describe, and I hope I've given you the idea, Ed.
 
Now that makes sense. Kinda like swinging doors. The door in the closed position is the low point and open either way is riding high on the "lobe", trying to return to the low point.
Gotcha. Dieseldog always has good replies, but I wasn't getting this one. So, the lunette, even the long one with spring will need the cammed housing to be effective? More $$ and maybe unobtanium.

Thanks,

Ed
 
Well, the ring will always align to the pintle without a spring/cam thing when the trailer is hooked up, and the spring doesn't and couldn't have sufficient strength to prevent the trailer from flopping over if poorly loaded or taken into an area that requires such drastic misalignment to the towing truck, so it's more a nicety than a necessity, I think, particularly if there is a sizable disparity of pricing.
I think you do want one that will turn but may not need the spring loading.

Something that occurs to me as I type this is that the spring does correct the lunette when the trailer is not hooked up and thereby readies it for engagement again. You can do that manually just as well if the lunette can be pinned into it's horizontal position.

Can you tell that my lunette rings don't spin? They don't and I don't have an offroading trailer either, only flat road ones.
 
Although it is possible that the spring gives some "rotational stability" to the trailer, its main function is to keep the conical root of the lunette in place, while allowing rotation around the root. The main idea of the design is to keep the conical root in place, allowing for the trailer to roll over w/o rolling over or putting any undue pressure on the towing vehicle.
 
When all the talking is done, the spring on an M416, M100, M101cdn... Does not do anything to "stabilize" the trailer. The rotationg lunette allows the trailer to roll with no restriction so that it does not pull the towing vehicle over with it. BTDT more than once. The spring is to absord towing shocks. That's it.


Mark...
 
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