Pintle hook mounted directly to Shorty Forty rear bumper? (1 Viewer)

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Mar 8, 2017
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Location
Australia
I have a Hayman-Reese (2") tow bar and it is fitted to the BJ40 by bolting onto the chassis and uses the four factory trailer hitch holes in the rear bumper. See pic below.

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I want to retain the Hayman Reese towbar for use with normal tow ball hitches, but I want to be able to mount a pintle hitch to the factory mount. Besides, the Hayman Reese bar has loops for the trailer chains so I don't need to find looped bolts long enough.

Why not just continue to use the pintle hitch in the photo? It sits too low for the trailer, which has SOA suspension.

Why not use one of those plate type tongues to which a bolt-on pintle hitch can be bolted at various heights to make the pintle hitch higher? Tried that and discovered the spare wheel carrier latch doesn't open, let alone the tailgate.

My proposed solution is to use a lockable, rotating pintle hitch bolted in the FJ40/BJ40 factory location. Since it can be unlocked and rotated, it will clear both the tailgate and the spare carrier latch.

My question to you guys is two-fold:

1. Who runs a pintle hook bolted directly to factory mount on the bumper?
2. What rated bolts did you use to mount it?
 
I did on my 80 until I got a 4x4 labs bumper which eliminated the rear cross member. I used grade 8 or equivalent. It is a ball pintle combo which was pretty handy.

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On a '79 FJ40 I had a pintle mounted directly to the rear cross member factory holes. I towed a 1200 lb M101 trailer with it.

That was enough years ago you could still buy grade 8 bolts at places other than Fastenal. IIRC that's what I used.

I only used it around my place and did not add any hook-ups for safety chains.
 
Thanks guys. I'll go ahead and bolt the pintle hook to the factory mount.

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I'm using a lockable/rotating British and Australian military pintle hook (see manufacturer's page here - 4.08T Light Towing Pintle - Bradley)

It's the same pintle hook fitted to land rovers so I found the details in an army parts book -

The bolts are M12 70mm long and grade 8.8. The nuts are 12mm locking nuts, grade 8. I picked up a box of 16 of bolts, nuts and washers which are same specs but are 75mm long to hopefully help clear the Hayman Reese towbar plate.

Here's an exploded diagram of the pintle hook.

pintle-hook-bolts.jpg
 
The US military used both rotating and fixed pintles on the small vehicles. As I recall the CUCV pintles were rotating and the jeep versions were fixed.

The rotating type ought to be perfect for off road applications.
 
Will the tow ball slider place the ball out far enough to not get hung up in the pintle?

8.8 bolts are roughly SAE Grade 5, not strong enough. You want 10.9's at least.

I have one of those ball/pintle combo's and I used to think it was a good idea. I no longer do. No lunette fits and works well. They'll all bang and make noise.
 
Will the tow ball slider place the ball out far enough to not get hung up in the pintle?

8.8 bolts are roughly SAE Grade 5, not strong enough. You want 10.9's at least.

I have one of those ball/pintle combo's and I used to think it was a good idea. I no longer do. No lunette fits and works well. They'll all bang and make noise.

Thanks mate.

I'll track down some stronger bolts.

The pintle hook in the pic above is old-spec and has a locking latch jutting out of the bottom. If the military pintle I'm receiving has one of these then the tow ball slider won't fit and I'll need to remove the pintle hook before towing a normal ball hitch-equipped trailer.

If it's the new-spec rotating pintle hook like the one in the parts diagram above, then it won't have the lock and the ball hitch slider will fit fine by simply rotating the pintle on its side.

With military surplus it's luck of the draw to the extent that I may or may not even receive a set of mounting bolts. All I know is that it's a pintle hook taken off an Australian military land rover that's been refurbished in service before being declared surplus.

When it arrives in a day or two I'll update the thread.
 
The US military used both rotating and fixed pintles on the small vehicles. As I recall the CUCV pintles were rotating and the jeep versions were fixed.

The rotating type ought to be perfect for off road applications.

The Aussie mil trailer I have (Aussie Military Trailer) was originally built in the early 1960s with a rotating lunette ring, and the pintle hooks on the Australian military vehicles were fixed - identical in fact to the pintle hooks on a WWII Willys MB/Ford GPW jeep. Rotating pintle hooks were introduced into service in the later 1960s with the Series IIA and Series III land rovers and then the 110 and by the 1990s the lunettes on the bulk of the trailers had been modded to be fixed. Mine was so-modded.

The various mil vehicle geek forums reckon that if your pintle is fixed and the lunette is fixed then you can encounter a situation out bush where if you somehow flipped the trailer it would flip the tow vehicle. I don't know the physics or mechanics of such an incident but it would suck if it happened hence my change to a rotating pintle.
 
I remember reading about discussions of the possibility of such an occurrence of rollover induced by the trailer, but not about one seen firsthand. No matter, it's indeed better to have something rotate freely if the trailer were to tilt to the extent that something could be damaged if there were no give someplace in the system. I'd guess that with a typical size pintle hook and lunette it'd be around 45deg maybe? On this side of the Pacific, it does seem to me that the rotating lunette was (still is?) the preferred approach by the military for some time, in contrast to rotating pintle hook, though.
 
I think it was "volcanic iceberg"'s thread where the possibility of a rotating lunette "rolling under" while backing up and jack-knifing the trailer could lock up the whole assembly and the resulting damage was pictured. I welded a 'fin' onto my pintle that limits this behavior. I know that I've posted pics of the fin and of my rotating lunette, perhaps in the same thread?
 
I think it was "volcanic iceberg"'s thread where the possibility of a rotating lunette "rolling under" while backing up and jack-knifing the trailer could lock up the whole assembly and the resulting damage was pictured. I welded a 'fin' onto my pintle that limits this behavior. I know that I've posted pics of the fin and of my rotating lunette, perhaps in the same thread?

I was thinking seriously of pulling apart my trailer and unlocking the lunette ring so it swivels 360 degrees, but there had to be a reason why the whole fleet of Australian army No. 5 trailers was modified with a locked lunette and rotating pintle and I think you just posted said reason. Cheers!
 

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