Ultimate M416 Axle Build, 6k Narrowed, Electric Brakes

[Rock40]

So it’s time for a bit of an M416 upgrade and I will try to keep this short

I’ve had the M416 for 14 years now, was bone stock and did a full rebuild. The RTT is on a telescoping rack with gas pistons, has onboard water and lighting. I’ve towed it all over the Western US behind the 40, Moab, Rubicon, etc. It’s been up and down the Alcan several times and I’ve always run the stock axle and goofy NDT military tires. I’m over it. The tread wears quickly, occasionally it fully separates from the steel core and when towing downhill off-road the lack of brakes sucks. Plus it’d be nice to have a matching 6 lug pattern.

I actually bought a custom length 3500# Dexter axle, then laughed and sent it back when it arrived. Didn’t realize they all utilize a torsion tube and the 3500# spindles are puny and dumb. No thanks

Looked into converting the lug pattern using FJ40 wheel hubs. Didn’t like the goofy (and expensive) bearings you have to source, drilling multiple extra holes in the 416 brake drum and the fact you still wouldn’t have brakes. Part of the thought process is the ability to procure replacement parts ANYWHERE so I ditched that idea

Ended up sourcing parts to do a complete build using 6000# spindles which happen to be the largest spindles you can use and still be 6 lug on the hubs. There is a night and day bearing size difference between 3500# and 6000# spindles and the bearings and seals are super easy to find.

Here’s a comparison shot. 6000# spindles next to a GM 14 Bolt spindle

 

[Rock40]

Picked up a piece of 2.375” DOM with a .25” wall thickness for the main axle tube. Machined the OD of the spindles down for a 2 thousandths tolerance fit into the DOM tube.

The spindles then spent several days chilling in the chest freezer. Preheated the DOM with a rosebud, grabbed the super cold spindles and slid them right in without any hammering required. In seconds, they were tight

 

[Rock40]

Welded the spindles and perches on. With how narrow I was shooting for, there is JUST room to pass the u-bolt between the perch and brake mounting plate

 

[Rock40]

Mounted the axle using the original parts…

Mounted the brakes and hubs…

Color matched a fresh Allied beadlock wheel…

DUN

 

[Rock40]

Different axles and modern wheels/tires really changed the look of things

And the tires are CLOSE to the leaf springs

Now to ditch the 5 lug spare and alter/fabricate a better tow connection than the lunette

 

[ntsqd]

Looks great!

I'm not convinced that there is a better off-road coupler than a pintle, so I'm interested to see what you end up doing.

Who's M715 in the background?

 

[Rock40]

Looks great!

I'm not convinced that there is a better off-road coupler than a pintle, so I'm interested to see what you end up doing.

Who's M715 in the background?

Thanks, I agree the pintle is great. I’m just sick of the low speed noise off-road and the difficulty with backing it up since the connection isn’t very “positive”. Will likely eventually go with a Max Coupler or similar in the future. I’m leaving for Alaska in about a month so I’m currently modifying the trailer pintle to accept a 2” square tube and a standard 2 5/16” ball.

The 715 is a LONG project at this point for a friend of mine.

Builds - 68' M715, AKA "Smokey" (Can I post this Jeep on MUD?)

Go ahead, flame me if you wish. After completing a very original frame off chassis restoration on a 66' FJ40 for a customer in California, it's time for a little something different. Yes, it's a Jeep. Let's be realistic though, the only "Jeep" part left is the frame and sheet metal...

forum.ih8mud.com

 

[ntsqd]

The common source of noise with a pintle that I see is that people use a lunette with a small cross-section. That obviously isn't the problem here. hum..... I wonder how far down the pintle's opening can be closed up before it quits working as it should? And would that be enough to reduce or stop the noise? I have not heard mine make any noise, and that has surprised me as I highly doubt that I've done or have anything special. Maybe I just need to log more miles with it?

Oh boy, that thread looks like an interesting read!

 

[clrussell]

Great build. I have one similar. I love that your water supply is below the bed floor, that’s a planned mod for mine.

I used this hitch and love it. I got mine off eBay though.

https://www.aliexpress.us/item/3256803951035837.html?src=google&src=google&albch=shopping&acnt=708-803-3821&slnk=&plac=&mtctp=&albbt=Google_7_shopping&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=19623912707&albag=&trgt=&crea=en3256803951035837&netw=x&device=m&albpg=&albpd=en3256803951035837&gad_source=1&gbraid=0AAAAAD6I-hHe08gxvZ6zkVr1QBwpuwTDV&gclid=EAIaIQobChMI-Iun18GNhgMVdjrUAR1xOgT1EAQYHCABEgKNAvD_BwE&gclsrc=aw.ds&aff_fcid=c21718b32b9a4aa484c3341cbe6444a0-1715702469862-00235-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=c21718b32b9a4aa484c3341cbe6444a0-1715702469862-00235-UneMJZVf&terminal_id=b7661e680a20409587d5f66c77c6b49c&afSmartRedirect=y&gatewayAdapt=glo2usa

I can get actual product pics if you’d like. Zero rattle, easy hook up, solid connection.

 

[Exiled]

I towed a customized M416 all over the US back in the late 90s/early 2000s (since sold). I lengthened the tongue on it but kept the lunette. One thing I'll say is that not all pintle hitches are created equal. I had an OEM Toyota pintle hook and that thing was TIGHT around the lunette of the the M416 (mine was a Stevens-built '67 model) and kept the clanking to a minimum.

 

[Rock40]

The common source of noise with a pintle that I see is that people use a lunette with a small cross-section. That obviously isn't the problem here. hum..... I wonder how far down the pintle's opening can be closed up before it quits working as it should? And would that be enough to reduce or stop the noise? I have not heard mine make any noise, and that has surprised me as I highly doubt that I've done or have anything special. Maybe I just need to log more miles with it?

Oh boy, that thread looks like an interesting read!

Yeah I don’t know. That’s a factory military lunette with a military pintle, it’s noisy. Going up Imogene Pass was awful from the Telluride side. IDK

It’s a super strong and very capable off-road connection, just too dang noisy for me. Probably made FAR worse by the fact I’m normally towing it in an open top FJ40

 

[Rock40]

I towed a customized M416 all over the US back in the late 90s/early 2000s (since sold). I lengthened the tongue on it but kept the lunette. One thing I'll say is that not all pintle hitches are created equal. I had an OEM Toyota pintle hook and that thing was TIGHT around the lunette of the the M416 (mine was a Stevens-built '67 model) and kept the clanking to a minimum.

And maybe that’s it, that the pintle is just too loose on the lunette. I am going to lengthen the tow point on the M416 by about 18”. It’s just too short overall, can’t even drop the tailgate on the FJ40 or FJ80 if the M416 is attached

 

[Rock40]

Great build. I have one similar. I love that your water supply is below the bed floor, that’s a planned mod for mine.

I used this hitch and love it. I got mine off eBay though.

https://www.aliexpress.us/item/3256803951035837.html?src=google&src=google&albch=shopping&acnt=708-803-3821&slnk=&plac=&mtctp=&albbt=Google_7_shopping&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=19623912707&albag=&trgt=&crea=en3256803951035837&netw=x&device=m&albpg=&albpd=en3256803951035837&gad_source=1&gbraid=0AAAAAD6I-hHe08gxvZ6zkVr1QBwpuwTDV&gclid=EAIaIQobChMI-Iun18GNhgMVdjrUAR1xOgT1EAQYHCABEgKNAvD_BwE&gclsrc=aw.ds&aff_fcid=c21718b32b9a4aa484c3341cbe6444a0-1715702469862-00235-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=c21718b32b9a4aa484c3341cbe6444a0-1715702469862-00235-UneMJZVf&terminal_id=b7661e680a20409587d5f66c77c6b49c&afSmartRedirect=y&gatewayAdapt=glo2usa

I can get actual product pics if you’d like. Zero rattle, easy hook up, solid connection.

Interesting. On the trailer side connection, you had to fabricate some sort of attachment plate?

 

[clrussell]

Interesting. On the trailer side connection, you had to fabricate some sort of attachment plate?

Mine has an extendable tongue on it. But yes, 2x4 tubing knotched around the 2” square, hitch bolted to that

 

[clrussell]

Also. I made my trailer as wide as possible, the extra 2 feet of sliding tongue makes it tow like a dream down the highway.

 

[ntsqd]

What I'd suggest doing for the tongue is like that above, but make it so that the coupler/Lunette/whatever is attached to a section of receiver tube that pins to the extending tube. That way you can remove it and now there's no way for someone else to tow the trailer. Add a second pin while you're there, it will take the slop out of that connection. I like to make the second pin holes 90° to the first pin holes but it isn't absolutely needed. Can also make up different coupler assemblies so that the trailer can be towed by something that only has a ball or only has a pintle or etc.......

Our TrailBlazer camp trailer's new frame was built with an extendable tongue, but after trying it I've never felt the need to tow in the extended position. Every trailer is different. This one doesn't need it while I'm sure others need it desperately. I do use the extending feature when moving the trailer around the yard by hand, THAT is very handy!

 

[Rock40]

Thanks for all the input here, I like the sliding tongue idea. I might pursue that in the future although my space is limited. I have an AGM battery mounted up under the front of the trailer currently. And a longer tongue would certainly make it easier to push around by hand!

 

[clrussell]

On my tongue the tube it slides into goes to the back of the trailer as a spine to a rear receiver.

I have the big pin and a 1/2” bolt I tighten to keep the slop out. Zero rattled while towing.

 

[Rock40]

That’s awesome, I really like that. Way too late for me to do that with mine tho, I’ve got the battery, water tank, etc all tucked up where that tube would have to run

 

[ntsqd]

Our TrailBlazer's new frame was built the same way, the receiver tube extends all of the way to the rear of the trailer. I am convinced that this isn't necessary. As I didn't build it I don't have pics from during the process. Looks like I don't even have good pics of it at all. Best that I have of the tongue:

AFAIC the receiver tube only needs to be a little longer than the fully collapsed length of the extending tube and have both ends tied into frame structure.