M416 Build (was "Starting from Scratch - Recommendations?")

[dieselcruiserhead]

Finally scored my M416 trailer. It is a pretty neat 1967 that came from Pennsylvania that is actually technically (I believe) a pretty rare 416 that is a couple inches wider, called a M614 or this is how it's identified on the tag. If you google M614 trailer it yields some cool results...

So I'm unsure of what to do with it. My interested is pretty much because I always wanted one and never had one My friend Damon with a sweet BJ42 wants to build it with me and it will sort of be "ours..." It is more useful for him as BJs are so small but would be fun to pull behind and use with my mini truck versus sleeping on the ground....

It tows like a dream, 75 mph without batting an eye and it is so light you don't even notice it there. All I noticed was slight loss of mileage. It does jackknife easy in reverse so I am planning to extend the tongue. Plenty of surface rust but no rot so we are going to take it apart and sand blast it, probably after thanks giving some time. And from there we have a nakid platform and are unsure what to do.

I'm interested in relatively minimal project/not tons of fab. I was thinking clean and paint and a nice lid. Possibly a roof top tent and possibly a tailgate. Not sure if I want to cut out the tail gate. We could do this really cleanly and have it functional. And not that I ever cross deep rivers but I like the idea of an unmolested M416 and I hear this might be the way to go.

I don't have much time for fab but Damon does this winter (within reason I think) so we could make it semi complex or not. I like the idea of a stand-alone unit with a stereo and all that but am not 100% sold on it and all that work.

Also not sure on suspension. I have some decent 60 series springs outside (and also some coils and matching shocks) that I could do an independent suspension with semi-imitating the AT stuff. Not sure if I am up to the fab for that right now or not. I was thinking SOA but switch to the longer/shallower 60 springs with new hangers to reduce height but still gain a couple inches in the SOA configuration...

I sort of like the stock military tires. I do have some tall skinny 9 x 16 Michelin XL tires around (measure about 36" - huge) lying around that would fit on the stock rims. I also have 33 x 10.5 x 15 tires and rims which is what will be on the mini truck that will be pulling it most of the time.

RE color: Damon's BJ42 is tan. My 55 will be white/orange and the mini truck is baby blue. Not sure what color I should paint it. A desert camo might be sort of fun, I dunno... It is important that it "looks cool" as always, LOL...

I'm all ears if you guys have recommendations...

 

[dieselcruiserhead]

The trailer and the BJ42

 

[GLTHFJ60]

My humble suggestions include:

1. Cut in a tailgate, because loading tires and such can be a pain if you have to lift it up that high, especially after doing an SOA.

2. Skip the independent suspension and order a 3500# axle with the standard toyota bolt pattern - less spares to carry

That's what I'm planning on doing with my trailer as soon as I get a garage to do this in. As for the 60 series springs, that's a great idea not only to get it lower but they are significantly longer yielding more suspension flex if it's ever towed off road. I don't think I've ever seen anyone do that, but I might try it myself!

 

[fj40fax]

Let's talk sometime about the suspension. I have been wanting to do an ind suspension on my trailer, and I don't think it will be that hard, or expensive.

 

[Exiled]

I am not sure that going with 60 series springs will yield a lower height after a SOA conversion on it, the spring packs on the M416 aren't that big, and you can easily take out the bottom two leaves, which are really short. I'd keep the stocksprings but definitely swap out the axle to a 3,500 lb. unit with standard 6-lug axle hubs (easy to service, parts everywhere, and will share spares with the 55, the mini and the BJ42.

The tongue extension is one of the best mods you can do, and it's pretty easy.

 

[Brian in Oregon]

It's wider than a standard M416? Or wider than an M100 or WWII trailer?

Can you post the measurements, please?

 

[dieselcruiserhead]

I will... I was with a guy who knows his M416s and he could have sworn this one was just a couple inches wider at the top. This may not be the case though. I started digging deeper in the M614 thing and there is a rumor that it was a USMC variant but looks like it was just straight up some weird dialect. So nothing fancy, just a different name...

Good call on the 6 lug and the axle. Yes something I'm considering..

 

[dieselcruiserhead]

RE FJ60 springs I'm trying to mimic my good friend Kurt's trailer where he uses long and soft FJ55 springs with a straight axle. Absolutely hauls ass so this appealed to me. I also don't like the spring hangers so I figured both would be a good addition. I can pull out some leaves to soften it up...

Just thinking aloud here..

 

[Exiled]

The Marine Corps variant is the M416B1, there's a couple of minor diferences tied to the designated tow vehicle (M422 Mighty Mite vs. the standard M151 Mutt) but the tub should be the same for all M416 variants.

Never heard of an M614 before, I'd love to see the tag, that sounds interesting.

Kurt's trailer should be heavier than an M416, right?

 

[fj40fax]

Found this thread which is exactly the type of frame I have with a full bed on mine. Really a blank slate.

https://forum.ih8mud.com/trailer-tech/129864-radish-trailer.html

I don't know if I have any pictures of it assembled, but it is all torn down to the frame now.

 

[SUMMIT CRUISERS]

Here's a couple pics of my 614m I picked up a few months ago. One is the inspection plate and the other is hooked up to my 75. What my research came up with is that the 614m is the Marine Corp version of the army's 416.

 

[dieselcruiserhead]

Cool, looking good. Henry correct Kurt's trailer is signifcantly heavier than a M416 would be. I'm starting to have it in my head to go ahead and start doing the imitation AT style arms and just do it right and do it once But am still on the fence. I'm really excited to get it torn down and sand blasted

 

[Exiled]

Here's a couple pics of my 614m I picked up a few months ago. One is the inspection plate and the other is hooked up to my 75. What my research came up with is that the 614m is the Marine Corp version of the army's 416.

Am I missing something? It says "M416" on the first line of the tag???

 

[dieselcruiserhead]

Check out about the 5th line down. It say model # 614 and then repeats it again. Mine looks about the same... I wish mine were that clean and legible, I wonder if acetone will clean it up...

 

[Exiled]

Check out about the 5th line down. It say model # 614 and then repeats it again. Mine looks about the same... I wish mine were that clean and legible, I wonder if acetone will clean it up...

Those are manufacturer codes, the first line says M416. I need to pull my tag out of storage to take a peek at it.

 

[jonb96150]

x2 on the tailgate. I've had 2 416's and one already had a tailgate. Big improvement. Especially if you soa on big tires you are going to hate lifting ice chests, etc... over the side.

I don't think they are rare enough to worry about the alterations. But some folks don't like to tinker with any milsurp stuff but to me a tailgate is a must have. Especially if you have a tent over it. With a tailgate and a sliding drawer you could still access all your gear.

 

[fj40fax]

Here are the spindles for 2x2x1/4 tubing

Tie Down Axle Spindle — 1 1/2in. Square, 8in. Long, Single | Axle Spindles | Northern Tool + Equipment

Here is the general design for the arms, hard part will be keeping the top and bottom parallel.

Adventure Trailers Suspension Review from JeepBrokers.com

and here is what i was thinking for suspension

Amazon.com: VW Bug Dune Buggy Adjustable Coil-Over Shocks Pair: Automotive

It won't ride as nice as the airbags on an AT for sure, but should work on the same principle without the gigantic shock angle on the first airbag version. Somewhat adjustable, and super cheap.

LMK if you think i'm crazy, but I think this could be a sweet setup.

Fax

 

[GLTHFJ60]

Those are manufacturer codes, the first line says M416. I need to pull my tag out of storage to take a peek at it.

I'd check mine as well but it's 220 miles away from me right now. When I bought mine I didn't even think to look at what model it was.

 

[dieselcruiserhead]

I was thinking for the height that the M416 will have to match the truck that I should be able to get a shock pretty upright or at least at a 45 degree or heigher. Henderson on State Street in Orem (and throughout Utah) has really killer prices on axle parts, and here is their catalog...
Catalogs

I considered coil overs too. I was thinking something much softer than a VW spring though (though that price is right). The airbags are probably a couple hundred and I could probably rig it with a gauge and an air fill per side and that would be pretty neat. Martyn says his arms are the hardest part to fab and they have something like a 20% rejection rate probably due to warpage in the welding process. I'm sure if I measured and measured and measured I could get it to work well...

Here are the spindles for 2x2x1/4 tubing

Tie Down Axle Spindle — 1 1/2in. Square, 8in. Long, Single | Axle Spindles | Northern Tool + Equipment

Here is the general design for the arms, hard part will be keeping the top and bottom parallel.

Adventure Trailers Suspension Review from JeepBrokers.com

and here is what i was thinking for suspension

Amazon.com: VW Bug Dune Buggy Adjustable Coil-Over Shocks Pair: Automotive

It won't ride as nice as the airbags on an AT for sure, but should work on the same principle without the gigantic shock angle on the first airbag version. Somewhat adjustable, and super cheap.

LMK if you think i'm crazy, but I think this could be a sweet setup.

Fax

 

[ntsqd]

Keep in mind that AT has to keep production moving. So they really don't want to let something cool and then check/straighten it between each weld as that would drive costs way up. This will have an affect on warping the trailing arms during fabrication. By how much I do not know since I haven't been there.

I have some concerns over going too soft. Rider comfort isn't a concern (is it???), so a super soft and slinky suspension for a trailer isn't the order of the day. Soft enough to not shake up the beer or break the eggs is good enough.
My guess is that you could use the OE front bump stops on late model GM 4X trucks (those trucks use them as a spring - they sit on them at ride height!!) as the sole 'spring' in a trailing arm suspension. To get the stroke desired it would need to be up near the pivot point. Those and some shocks and I think you'd be good to go. Recall the the original Mini's used a rubber block as their sole spring, so the idea is not without precedent.