My DIY tow bar

[Rutjes]

Hey guys,

I might need to move my M1009 soon, so I started fabricating a tow bar today. I want to keep it around and mount it in the bed of my M1028 by the time I get to that. Who knows when it might come in handy.

Tube is 40mm (1 9/16" )square tubing with 4mm (5/32") thick walls. The flat iron bar is 6mm (1/4"). I think it's strong enough, but I might put another one on top to make it stronger. It's what I had available to me. The "hinge" bolts are 16mm (5/8"). Bolt at the shackle hanger is 24mm (15/16"), a tad too small. Next size up is 27mm, but those won't fit the shackle hangers. I will probably drill out the holes on the tow bar and use the pins holding the shackles to get rid of any slack in there. I need to get proper sized and shanked bolts, these are just for test fitting.



Not sure how to mount the eye yet. Hope you guys go easy on me after seeing the thread from the guy welding angle iron to the shackles .

 

[Mullaney]

Hey guys,

I might need to move my M1009 soon, so I started fabricating a tow bar today. I want to keep it around and mount it in the bed of my M1028 by the time I get to that. Who knows when it might come in handy.

Tube is 40mm (1 9/16" )square tubing with 4mm (5/32") thick walls. The flat iron bar is 6mm (1/4"). I think it's strong enough, but I might put another one on top to make it stronger. It's what I had available to me. The "hinge" bolts are 16mm (5/8"). Bolt at the shackle hanger is 24mm (15/16"), a tad too small. Next size up is 27mm, but those won't fit the shackle hangers. I will probably drill out the holes on the tow bar and use the pins holding the shackles to get rid of any slack in there. I need to get proper sized and shanked bolts, these are just for test fitting.

View attachment 838155 View attachment 838156 View attachment 838149 View attachment 838150 View attachment 838151

Not sure how to mount the eye yet. Hope you guys go easy on me after seeing the thread from the guy welding angle iron to the shackles .

.
Nice! Heck of a welding job there too. There isn't any bubblegum flowing out of your welder!
Just looking at it, it seems beefy enough to drag that truck anywhere you would want to pull it.

I was looking at the bolts and giving them the evil eye, then I went back to read again and saw "test fitting".

 

[98G]

With military issue towbars being cheap and plentiful, I would be extremely reluctant to fab one just from the standpoint of liability if things go sideways.

When I do fab something that will be used on the road, I try to make sure that the part I fab won't be the first thing that breaks if the whole system is overloaded. In the case of a towbar for flat towing a cucv, I would want to make sure that the stock shackle mounts break before my piece does. I don't see that being the case here. If the whole thing is overloaded and something has to break, the first thing that breaks will be your 1/4" plates, where the 1" pin goes.

You'll probably get away with it. I just don't have a warm fuzzy feeling about it.

Edit to add - 1" clevis pins are available from tractor supply and such places. While they aren't as strong as military towbar pins, they are more than overkill for a cucv.

 

[gringeltaube]

Not sure how to mount the eye yet. ..............

Depends what you have in mind.... a fixed triangle, 1-pc design, or rather an adjustable 2-arm towbar, like the military uses?

Almost sounds like your towbar will only be used for either one of your CUCVs (?) The distance between mounting points should be more or less the same for both vehicles so your towbar could be a non-adjustable 1pc design, where the tubes could be welded directly to the eye's shaft.


Now, if this thing was intended to be fixed, then why that extra horizontal articulation at the shackle end? The only movement will be up and down, pivoting at the shackle mounts...

 

[Rutjes]

Nice! Heck of a welding job there too. There isn't any bubblegum flowing out of your welder!

Thanks! Been teaching myself how to (MIG) weld the last 3 years so. Trial and error and lots of YouTube videos .

With military issue towbars being cheap and plentiful, I would be extremely reluctant to fab one just from the standpoint of liability if things go sideways.

When I do fab something that will be used on the road, I try to make sure that the part I fab won't be the first thing that breaks if the whole system is overloaded. In the case of a towbar for flat towing a cucv, I would want to make sure that the stock shackle mounts break before my piece does. I don't see that being the case here. If the whole thing is overloaded and something has to break, the first thing that breaks will be your 1/4" plates, where the 1" pin goes.

You'll probably get away with it. I just don't have a warm fuzzy feeling about it.

Edit to add - 1" clevis pins are available from tractor supply and such places. While they aren't as strong as military towbar pins, they are more than overkill for a cucv.

The military tow bars aren't that plentiful on this side of the pond. I guess that's 1 vote adding extra flat bar on top of the current ones.

Depends what you have in mind.... a fixed triangle, 1-pc design, or rather an adjustable 2-arm towbar, like the military uses?

Almost sounds like your towbar will only be used for either one of your CUCVs (?) The distance between mounting points should be more or less the same for both vehicles so your towbar could be a non-adjustable 1pc design, where the tubes could be welded directly to the eye's shaft.
View attachment 838161

Now, if this thing was intended to be fixed, then why that extra horizontal articulation at the shackle end? The only movement will be up and down, pivoting at the shackle mounts...

I would like to have it adjustable. More compact for storing and hauling it around. I think I have to have the eye fixed to 1 of the tubes and have the other able to articulate.

At first I just copied the military design. I want it to be "universal". I might swap my K1500's ? shaped tow hooks for some CUCV style D shackle mounts.

In the past I copied the D shackle mounts and put them on my Iveco Daily. I still have them on the back. They looked silly on the front. I might put them back now tough. It would be nice to be able to flat tow any of my vehicles in case it is ever needed. No need to rely on others to get a tow.

 

[98G]

Thanks! Been teaching myself how to (MIG) weld the last 3 years so. Trial and error and lots of YouTube videos .



The military tow bars aren't that plentiful on this side of the pond. I guess that's 1 vote adding extra flat bar on top of the current ones.



I would like to have it adjustable. More compact for storing and hauling it around. I think I have to have the eye fixed to 1 of the tubes and have the other able to articulate.

At first I just copied the military design. I want it to be "universal". I might swap my K1500's ? shaped tow hooks for some CUCV style D shackle mounts.

In the past I copied the D shackle mounts and put them on my Iveco Daily. I still have them on the back. They looked silly on the front. I might put them back now tough. It would be nice to be able to flat tow any of my vehicles in case it is ever needed. No need to rely on others to get a tow.

View attachment 838178 View attachment 838179

The thing about MIG welding is that with some practice you can get nice pretty welds that look great.

Getting welds that penetrate is a bit harder. Especially with 120V machines. And the only way to know if your welds are penetrating is to have them destructively tested, until you *know* you're producing a high quality penetrating weld.

I went to school to learn welding. I got the 5G pipe cert in stick welding and also the structural MIG cert. I would not use the MIG process for anything mission critical to be used on public roads.

I'm not saying your welds aren't good. For all I know they're perfect and penetrate well. But generally speaking, intermediate level welders tend to go cold and slow with MIG and create decent looking welds that lack penetration. (And beginner MIG welders go cold and slow and create ugly boogery looking welds that lack penetration...)

Note that hitch companies typically use a dual shield Flux core type process for their welds. The welds on the military issue towbars also look to have been run with dual shield, very hot and fast.

MIG leads itself to a very high productivity rate, but is the most difficult process to get a really strong weld out of.

 

[nyoffroad]

I can't comment on the welds but why not make it adjustable AND instead of keeping it in the bed where it's in the way and rattling around make some brackets and bolt in the 'dead' space UNDER the bed? Yeah it would suck having to crawl under in the mud to get it but it would always be with you and out of the way.

 

[Lothar]

I hope you will take my input as it is intended, only to be helpful. I am a professional welder/ fabricator with 28 years in the trade. Last 15 or so pipe certified in stick and tig. Want to commend you for coming up with your own solution that will probably work well if you are moving your vehicles around your property. However, if you intend to haul on the highway, I have to agree with others that your plates should be no less that 3/8" thick and hardened pins or at least grade 8 bolts used in your connections. While the 1/4" will work it can very easily fail with fatigue and wear over time. Please consider the safety of the innocent people you might be putting at risk with a substandard fabrication. I have had 1/4" suspension brackets on my own truck fail and had to completely rebuild with 3/8" plate. If any single point in your towbar fails at speed, it is very unlikely you will be able to recover safely. It sounds like thicker plate might not be available to you so I would very closely inspect the 1/4" plates before each use. Looking for the holes opening up, cracks appearing around the welds and the holes. And replace the plate entirely when those signs appear. Also there is no clear view of the inside of your "yoke" pieces so I can't tell but I would also weld that edge of the tube to the plate if you haven't already. Best of luck to you and keep on weldin'. Looks like you've developed a pretty decent hand and it will only get better unless you stop.
* edit* Regarding the welding of the lunette ring, it is most likely a cast piece that I would stick weld using some preheat and a 7018 rod. Add a plate to the top and bottom that will connect both square tubes and the ring. Weld everywhere possible.

 

[cucvrus]

I have worked at a truck body manufacturing plant for over 30 years. We have built 10's of thousands of fleet trucks with liftgates and tow hitches. Some even tow from the lift gate in the folded position. I myself welded hitches on truck frames for Ryder, Penske. Budget and all major rental truck companies. We always used Miller mig welders and welded with 75/25 gas thru a major manifold system in the truck shop. We use .045 welding wire and I never heard of a hitch failure yet. We train welders in house and most welders are welders when they come thru the door. I think the military tow bars are build way too heavy for the CUCV they are towing. I have 3 military tow bars and have loaned them to other people to tow CUCV's , 2 1/2 ton and 5 ton trucks. I have a brand new medium tow bar that I can hardly lift. I have been pinched more then once loading and unloading the tow bar. I think the tow bar he has made will do the job. I also think of my utility trailer. It is 35 years old and made of 3/16" 2 X 2 angle and welded to a stamped ball receiver. all them years of use and hauling everything and it still goes up and down the road. The safety chains and S hooks are the only connection after failure and it it unhooks or the frame fails nothing is going to change. It will have to be stopped. I think about the M416 trailer. How much steel and weight must you add so it is 100% safe. I think it will work great and the welds look good. Just saying. Bigger and heavier is NOT always better.

 

[Rutjes]

I can't comment on the welds but why not make it adjustable AND instead of keeping it in the bed where it's in the way and rattling around make some brackets and bolt in the 'dead' space UNDER the bed? Yeah it would suck having to crawl under in the mud to get it but it would always be with you and out of the way.

Noted. My idea was mount it to the bed above the wheel well. Brackets attached to the side panel.

I hope you will take my input as it is intended, only to be helpful. I am a professional welder/ fabricator with 28 years in the trade. Last 15 or so pipe certified in stick and tig. Want to commend you for coming up with your own solution that will probably work well if you are moving your vehicles around your property. However, if you intend to haul on the highway, I have to agree with others that your plates should be no less that 3/8" thick and hardened pins or at least grade 8 bolts used in your connections. While the 1/4" will work it can very easily fail with fatigue and wear over time. Please consider the safety of the innocent people you might be putting at risk with a substandard fabrication. I have had 1/4" suspension brackets on my own truck fail and had to completely rebuild with 3/8" plate. If any single point in your towbar fails at speed, it is very unlikely you will be able to recover safely. It sounds like thicker plate might not be available to you so I would very closely inspect the 1/4" plates before each use. Looking for the holes opening up, cracks appearing around the welds and the holes. And replace the plate entirely when those signs appear. Also there is no clear view of the inside of your "yoke" pieces so I can't tell but I would also weld that edge of the tube to the plate if you haven't already. Best of luck to you and keep on weldin'. Looks like you've developed a pretty decent hand and it will only get better unless you stop.
* edit* Regarding the welding of the lunette ring, it is most likely a cast piece that I would stick weld using some preheat and a 7018 rod. Add a plate to the top and bottom that will connect both square tubes and the ring. Weld everywhere possible.

I was already thinking about adding another plates on-top of the existing ones. Making them thicker. I could've ordered thicker iron, but this is what I had at the moment. Then again, I have to agree with cucvrus, more on that below.

Btw., I did try to break, cut and beat my welds before. They seem plenty strong. I have 230V MIG welder 35 - 220 A.

Bolts are 8.8. That's a standard bolt around here. The (approved) eyes on my trailers are held by two 12mm 8.8 bolts. Those trailers weigh up to 18000 lbs. Been driving trailers like that around on a daily basis for about 11 years now and never did one of the bolts holding them break so I'm confident in the 16mm bolts on the pivot points will do fine.

I have worked at a truck body manufacturing plant for over 30 years. We have built 10's of thousands of fleet trucks with liftgates and tow hitches. Some even tow from the lift gate in the folded position. I myself welded hitches on truck frames for Ryder, Penske. Budget and all major rental truck companies. We always used Miller mig welders and welded with 75/25 gas thru a major manifold system in the truck shop. We use .045 welding wire and I never heard of a hitch failure yet. We train welders in house and most welders are welders when they come thru the door. I think the military tow bars are build way too heavy for the CUCV they are towing. I have 3 military tow bars and have loaned them to other people to tow CUCV's , 2 1/2 ton and 5 ton trucks. I have a brand new medium tow bar that I can hardly lift. I have been pinched more then once loading and unloading the tow bar. I think the tow bar he has made will do the job. I also think of my utility trailer. It is 35 years old and made of 3/16" 2 X 2 angle and welded to a stamped ball receiver. all them years of use and hauling everything and it still goes up and down the road. The safety chains and S hooks are the only connection after failure and it it unhooks or the frame fails nothing is going to change. It will have to be stopped. I think about the M416 trailer. How much steel and weight must you add so it is 100% safe. I think it will work great and the welds look good. Just saying. Bigger and heavier is NOT always better.

You are right. Bigger and heavier is NOT always better. The military tow bar looks like way too much tow bar for towing a CUCV or vehicle of similar weight. I like making things stronger then they need to be, but there is a limit. Right now I'm leaning towards welding another piece of flat ontop of the existing ones, making them stick out a little bit on the square tube side, bend them down there and weld them to the sqaure tube as well. It will make them stronger and a little bit heavier, but not too heavy or bulky.

 

[Rutjes]

Wow, time flies! I've been too busy with my M1028, K1500 and my friend's M1008 to get around to working on this tow bar. I bought a tow eye a while back for this project.



Not sure how to mount it. I would like it centered, like how it is laid out in the second picture, but I think it would be to flexible and would move to much, especially when braking. I'm guessing I should have it fixed to 1 arm and have the other pivot? It is a "weld on" eye, but I don't think just MIG welding it will be strong enough as it is cast iron? I can grind it down a bit to make it slide into the tube and put some bolts through it? Any thoughts?

 

[Keith_J]

When it comes to bolting in shear loading, higher tensile strength can be less effective. Yes, higher grade bolts achieve higher clamping force with a loss in ductility.

Metric class 8.8 is the proper choice here.

 

[98G]

A good bolt is better than a poor weld.

For things used on the road or other places where failure would be critical, if you don't absolutely trust your welds, bolt it instead.

If I were welding that, it'd get multiple passes of 7018 stick.

 

[Mullaney]

A good bolt is better than a poor weld.

For things used on the road or other places where failure would be critical, if you don't absolutely trust your welds, bolt it instead.

If I were welding that, it'd get multiple passes of 7018 stick.

.
Agreed @98G

My opinion is that if you are standing in court where the towed vehicle "got away" and killed someone - having a certified card carrying welder that "glued" that metal together will be important.

 

[Keith_J]

Chains attached to independent points from the tow bar are always a good idea.

7018 are good rods if they are fresh. They don't stay that way, especially from your local hardware store. The key is ductility, 70 S6 GMAW with 75/25 Ar/CO2 can have issues.

 

[dougco1]

Wow, time flies! I've been too busy with my M1028, K1500 and my friend's M1008 to get around to working on this tow bar. I bought a tow eye a while back for this project.

View attachment 845265 View attachment 845264

Not sure how to mount it. I would like it centered, like how it is laid out in the second picture, but I think it would be to flexible and would move to much, especially when braking. I'm guessing I should have it fixed to 1 arm and have the other pivot? It is a "weld on" eye, but I don't think just MIG welding it will be strong enough as it is cast iron? I can grind it down a bit to make it slide into the tube and put some bolts through it? Any thoughts?

I think a pair of matching heavy triangular plates welded fast to the tow eye "top and bottom" with 2 holes to accept the arm bolt pins will work just fine. That will still allow for the adjustable tow bar width your looking for.