M116A3 Fix-up & Conversion Thread

[CallMeColt]

Making this thread to document what I have done to convert my newly acquired M116A3 over to tow with my civilian truck. Also wanted to document repairs I have done & sources for parts.

Got the trailer to mount my MEP-802A on & add my own things to make it an easy tool for power & fuel at my off grid place, backup power for my home, & mobile power in case disaster help is needed.

I started posting what I did in my MEP-802A Fix-up Thread but figured that to documentation would be better for the trailer part of it here in the trailer thread.

This is what the trailer looked like when I got it. Almost nothing wrong. Seller was asking $1500. $550 cash I paid. The only thing I could find wrong is the handle for the tongue jack is missing & the original pin for the rear kickstand.

Looking through some TM's I figured this originally was a PU-797 setup before the generator was taken off.



UPDATE: Here is the video I put together. Figured that I would add it here on the first post.

 

[CallMeColt]

Started looking at TM 9-6115-659-13&P & it seems like this trailer was from a PU-797 setup. In that TM, I can't find the parts diagram for the tongue jack. I'd just replace it with a commercial one, but everything with it works find except the missing handle for cranking it. Is there is a different TM that would have that part?

UPDATE: Added the pictures. Also, found a handle that I think should work from eTrailer. I can toss it in the toolbox when not in use. Here's a link;
http://www.etrailer.com/Accessories-and-Parts/etrailer/RVLG-HDL.html

 

[CallMeColt]

Zed254 on my MEP Fix-up Thread posted this information for the military handle for the tongue jack;

From TM 9-2330-202-14&P, Fig 17

8 PAOZZ 5340013863974 19207 12441073 HANDLE,BOW.......................... 1
UOC:CT1,SPR,TC1,258,263

 

[CallMeColt]

GuyFang posted these two Tactical Manuals that can be used for the M116A3 trailers;

TM 9-2330-202-14&P
TM-9-6115-659-13&P

 

[CallMeColt]

So I placed an order with eTrailer. Got an adjustable pintle hitch. I have one already but it's a bolt on type. Since I will need to adjust more with this new trailer, it was my excuse to buy the quick adjustable one so it's easy to hook up to any of my trailers. Ordered the 7 pin wire pigtail & the tongue jack crank that were both linked above.
I may make a video showing how the cord hooks up to the military wiring. The info is on here but a video is always nice.
Here are links to all 3 items in case someone else ends up finding this;

https://www.etrailer.com/Wiring/Mighty-Cord/A10-7W6.html

https://www.etrailer.com/Pintle-Hitch/Pro-Series/63072.html

https://www.etrailer.com/Accessories-and-Parts/etrailer/RVLG-HDL.html

 

[CallMeColt]

So, I started working on the trailer. Used the information I found here on the forum & wired up the 7 pin RV type connector that I ordered. Matched the green wire to 22460, Yellow to 22461, Brown to 21, & white to ground. Put in the proper 12v bulbs to the existing housing. Only the right side running light works. No left signal. Right signal put both on like the hazards. Hazard lights work. Brake lights work. Started getting late & I was a little annoyed that I didn't fully check ALL functions before closing everything up.

Things I'm going to try tomorrow;
-Make sure all the grounds are good.
-Make sure my connections are good.
-Swap running bulbs from side to side to be sure one of the LED's aren't bad.
-Confirm all connections to the light housings are good & proper.

Hopefully it's just a silly ground connection. Trailer lights are usually real simple.

Going to be a bit annoyed with myself if it all gets to deep since my original plan was to take all the wires off & just get the LED kit from Harbor Freight Tools for $40. I'd have a license plate light with that kit too.

Enough of my complaining for now. Just cranky after a long day. Starting fresh after work will help. At least I have A/C in my garage now!
Tomorrow the new wheels & tires come. Should ride level with them.

 

[CallMeColt]

Got it all figured out & finished yesterday. Will update with pictures later.

Apparently the required hook-up with the 7 pin harness I had was different. I noticed that the cover on my truck connection had what each pin was supposed to connect too. Confirmed with multimeter & changed up connections with the proper wires on the trailer.

For a 7 pin harness;
Green goes to 21
Brown goes to 22-460
Red goes to 22-461
White is the ground

For a 4 pin harness;
Green goes to 22-460
Yellow goes to 22-461
Brown goes to 21
White is ground

New wheels & tires came in. Bolted up nicely.

Ordered a plate bracket with LED light on it.

Went & registered it today so it's now road legal.

May need to check the surge brakes as it seems they're not working well.

Took a bunch of video along the way to share on converting this trailer, what I did, & what I purchased to make it happen.

Going to try & setup a time next week for the local generator shop to swap my MEP-802A over to this new one as my tractor won't to it safely.

I'm excited to see it all come together!

 

[CallMeColt]

Depending on how often you trailer, if the surge is giving you fits there is a cross hole through it that you can use a long bolt through to 'lock out' the brakes (especially handy if you are trying to back the thing up an incline...). I wouldn't use less than Grade 8 personally for the bolt, but its at least there.

Didn't know this & it was shared in my MEP 802A Fix-up Thread. Wanted to share it here.

On my trailer, the holes don't line up so you can't get a bolt through. Later down the road, I will pull the lunette ring off & make the internal hole bigger so I can do this.

 

[CallMeColt]

Zed254 in my MEP-802A Fix-up Thread shared a link to some of the parts for the surge brakes along with a parts break downs. You will need to know your exact model on your trailer, but cross referencing the TM part numbers with this website will find you want you need.

https://www.crofttrailer.com/surge-brake-actuators/?sort=priceasc

 

[CallMeColt]

Everything is done on the trailer & the service department at my local Kubota is going to move the generator over for me this afternoon!

I did discover that there is a little brake line damage. Will probably need to replace the lines to repair. Shouldn't be bad but it isn't necessary right now.

 

[Tinstar]

Once you get the surge brake system in shape, they work great and last for years without major maintenance.

The hole is to lock out the brakes while backing up a loaded M101A2/3 trailer.
Dexter, also a military supplier, makes a FreeBack brake replacement.
Very easy install.
It allows backing up a loaded trailer.

The M1101/02 trailers have them already installed.

 

[Guyfang]

Started looking at TM 9-6115-659-13&P & it seems like this trailer was from a PU-797 setup. In that TM, I can't find the parts diagram for the tongue jack. I'd just replace it with a commercial one, but everything with it works find except the missing handle for cranking it. Is there is a different TM that would have that part?

UPDATE: Added the pictures. Also, found a handle that I think should work from eTrailer. I can toss it in the toolbox when not in use. Here's a link;
http://www.etrailer.com/Accessories-and-Parts/etrailer/RVLG-HDL.html

View attachment 768075View attachment 768076

The jack is considered a "Pluck and Chuck" Item. If its broke, order another. It was deemed not worth the millions to stock parts for it. I have fixed several. When I got done with the last one, I was a firm believer in Pluck and Chuck in this instance.

 

[CallMeColt]

Once you get the surge brake system in shape, they work great and last for years without major maintenance.

The hole is to lock out the brakes while backing up a loaded M101A2/3 trailer.
Dexter, also a military supplier, makes a FreeBack brake replacement.
Very easy install.
It allows backing up a loaded trailer.

The M1101/02 trailers have them already installed.

Yes, it seems like they will be trouble free once I get them working.

 

[CallMeColt]

Here's what it looks like with all the work done & ready for my MEP-802A to be mounted.


Here's what it looks like after I mounted the generator. Put the accessory box & step plate that I removed at the start of the project on in my own spot.

 

[CallMeColt]

Added a link to the video I put together in post #1. It's still uploading as I type this, so it may not be available right away. Long & boring, but should help anyone looking to covert their trailer.

 

[Bulldogger]

Looks good. Well done. Did you figure out the surge brakes? I had an M116A3 former genset trailer too. All I ever had to do with mine was pull the wheels off and open and inspect, replace one broken spring, repack (grease) the wheel bearings and set the tension on the shoes. The brakes are pretty simple inside. If you ever opened an old truck or old car's drum brakes, everything will look very familiar. For replacement springs, grab a large truck rear brake rebuild spring kit, like for a Ford F350 or something. Usually they will have a spring you can use.

Hope it gives you years of trouble free service.

BDGR

 

[Tinstar]

Looks good. Well done. Did you figure out the surge brakes? I had an M116A3 former genset trailer too. All I ever had to do with mine was pull the wheels off and open and inspect, replace one broken spring, repack (grease) the wheel bearings and set the tension on the shoes. The brakes are pretty simple inside. If you ever opened an old truck or old car's drum brakes, everything will look very familiar. For replacement springs, grab a large truck rear brake rebuild spring kit, like for a Ford F350 or something. Usually they will have a spring you can use.
Hope it gives you years of trouble free service.
BDGR

Dexter and Redline still offer brand new brake rebuild kits.
It’s a Dexter axle.
No need for a truck brake parts kit since exact replacement kits are available.

Any decent trailer parts store should have the parts.

 

[CallMeColt]

Looks good. Well done. Did you figure out the surge brakes? I had an M116A3 former genset trailer too. All I ever had to do with mine was pull the wheels off and open and inspect, replace one broken spring, repack (grease) the wheel bearings and set the tension on the shoes. The brakes are pretty simple inside. If you ever opened an old truck or old car's drum brakes, everything will look very familiar. For replacement springs, grab a large truck rear brake rebuild spring kit, like for a Ford F350 or something. Usually they will have a spring you can use.
Hope it gives you years of trouble free service.

BDGR

Honestly, I haven't really dug in on them yet. All I did was go get some DOT 5 fluid today. My truck is big enough that I don't really need them but would like them to work. I have never worked on a brake system before except on an ATV... never needed too. I have the TM to guide me. I'm confident I'll get them working.

Dexter and Redline still offer brand new brake rebuild kits.
It’s a Dexter axle.
No need for a truck brake parts kit since exact replacement kits are available.

Any decent trailer parts store should have the parts.

There are multiple, large trailer shops near me so I'm sure parts sourcing won't be hard.

 

[CallMeColt]

Spent some time on the trailer today.



Got a bottle of DOT 5 fluid from the local auto parts store. The master cylinder was empty. Filled it & bled the brakes according to TM-9-2330-202-13-P work package 53. Page 265 of the .PDF file. After getting the air & crud out, the system seems to be fine. I could use a new cap on the master cylinder along with a gasket. Will get it sometime.

The surge brakes work real well... almost to well. At slower speeds, the brakes almost want to lock up & the trailer bucks a little. May be because it has such smaller & lighter tires now. Either way, I don't think it's a huge issue... just something to pay attention too.

I'm going to keep an eye on a fitting that may leak on the axle. If so, will just replace all the lines on the axle. Looks like they've been hit a few times.

Added a toolbox to the tongue from Harbor Freight Tools. Drilled 4 holes & tapped them so it's a direct mount. Fit's about 175ft of cable along with the tongue jack crank with room to spare. The only thing I'm unhappy with it is since it's such a thin gauge metal, it will make a little bit of vibration noise sometimes while the generator is running. I will remove the lock at a later time & put a regular hasp with padlock like the accessory box that came with the trailer.



Put a new locking hasp set on the accessory box since the top was missing on the one I got.

Received the fire extinguisher holder that I ordered & mounted it to the fender. It's not the original type one, but close... & is military surplus. Guess it's what goes in the MRAPV's. Made by Force Protection, part number 3010424. VERY secure. Going to order another one for my truck actually. Had a few of the extinguishers already.



Last but not least, I ordered a fuel tank from Aluminum Tank Industries. Spoke with them & they're going to put the mounting tabs so they will like up with the generator mounting rails. 50 gallon capacity. I wanted a little more but then it would need to be custom made or I'd have no access to the rear panel if needed.

I will plumb a connection to the auxiliary fuel input on the generator. Probably will add a transfer pump on as well for filling my ATV, Tractor, & anything else that needs diesel.

Very happy with how it's all falling together!

 

[Sgt Jiggins]

The surge brakes work real well... almost to well. At slower speeds, the brakes almost want to lock up & the trailer bucks a little. May be because it has such smaller & lighter tires now. Either way, I don't think it's a huge issue... just something to pay attention too.
Last but not least, I ordered a fuel tank from Aluminum Tank Industries. Spoke with them & they're going to put the mounting tabs so they will like up with the generator mounting rails. 50 gallon capacity. I wanted a little more but then it would need to be custom made or I'd have no access to the rear panel if needed.
I will plumb a connection to the auxiliary fuel input on the generator. Probably will add a transfer pump on as well for filling my ATV, Tractor, & anything else that needs diesel.

Colt that looks good! Thanks for all the pics.

Yea, the brakes on mine tend to buck a bit too. I just drug mine 800 miles down I40 the other day and that was a bit unnerving at points, particularly when raining, because, until I figured out what was going on, it wasn't clear to me if it was the ABS in the car doing it or what it was. My guess is that it's not normally going to be an issue for most folks, but something to be aware of "just in case".

I like your aux tank idea. Can you please post more pics/info on that? What model? More on how you mounted it? I'm not opposed to a larger tank if it requires mods/blocks access to the back panel. First because I can lift the genset off the trailer entirely if it comes to it, and second, because if memory serves, there's not much on that back panel that would require access? Or at least I don't have any hatches on that face that I am yet aware of (but I'm very green with these units at the moment)?

Thanks,
SJ/JD