M916 Novice!

[Kdubfan01]

Hello all, new m916 owner here! Actually first time military truck owner aswell! I have a few questions about it. When I picked it up it had 2 very dead group 31 batteries. I ran the screw out on the injection pump and jump started it to get it 50 miles home, it did pretty good other than the lack of a working tachometer made it difficult to shift the cat trans. How are you guys wiring in group 31 batteries in these so that the dash and lights get 12 volts and the starter gets 24? A picture would be great! I’ll include a picture of what I’ve got currently in my battery box. Also what rpm are you guys up shifting and downshifting the 7155? I just fixed the tachometer so we’ve got that now! I made sure to do my best to keep it above 1100 rpm on the way home. Last thing, when I got the truck the fuel tank was rotated way up. So I loosened the tank straps to rotate the tank back so the steps were level. In the process I broke the rear tank strap anyone know where I can get one? Heck a new battery box as well while I’m at it? Mine past deteriorated! Not my first rodeo with an old semi tractor, definitely my first rodeo with a old military semi tractor! Thanks guys!

 

[Guyfang]

You could start a "Parts Wanted" Thread.

 

[Mrgior31513]

Congratulations on your first military truck and welcome to the community

https://www.steelsoldiers.com/attachments/tm-9-2320-273-24p-pdf.494434/

Here is a link to the TM for the parts for your truck as best as I can figure in a few minutes of time.

I would recommend as a first thing to do is look up the TM's for your truck and get a bit familiar with them. They are like service manuals for dealerships, designed to instruct teenagers and twenty somethings on how to fix and work on these trucks, so they're pretty well packed with information from basics to full rebuilds. A lot of the guys on here would be happy to help complex problems, but a lot of the simple stuff they would prefer you to look up first. It's not too bad, considering. Figuring out a problem is usually the hardest part when short of experience.

For vendors, there are many. Eastern Surplus, Big Mikes Motor pool, Oshkosh, few others I can't remember off hand. Typing in something like "m939 parts" should pop up a ton of vendors, as well as looking up part numbers and looking for those.

 

[Kdubfan01]

Congratulations on your first military truck and welcome to the community

https://www.steelsoldiers.com/attachments/tm-9-2320-273-24p-pdf.494434/

Here is a link to the TM for the parts for your truck as best as I can figure in a few minutes of time.

I would recommend as a first thing to do is look up the TM's for your truck and get a bit familiar with them. They are like service manuals for dealerships, designed to instruct teenagers and twenty somethings on how to fix and work on these trucks, so they're pretty well packed with information from basics to full rebuilds. A lot of the guys on here would be happy to help complex problems, but a lot of the simple stuff they would prefer you to look up first. It's not too bad, considering. Figuring out a problem is usually the hardest part when short of experience.

For vendors, there are many. Eastern Surplus, Big Mikes Motor pool, Oshkosh, few others I can't remember off hand. Typing in something like "m939 parts" should pop up a ton of vendors, as well as looking up part numbers and looking for those.

Awesome, good thing I’m 20! Maybe I’ll understand the TM’s! I have been through the TM for it and of course it says to use the 6 volt military batteries. Those are $350 bucks a piece where I am and I can get a group 31 for $110. So I didn’t know how to convert it to the group 31. With the help of a young man in Oklahoma we got it figured out! Just looking for those parts now. I have been to Oshkosh and eastern surplus I just figured I’d see if anyone on here had anything they were willing to part with. Thanks for your help!

 

[NDT]

My battery box is wired up just like yours. The huge cables are 24 volt plus and minus, and the little 6 ga ? wire is 12 volt. You can omit connecting the slave receptacle if you don't have a use for it. Use the same stud top 31s you have now. The TM will tell you to use 4 ea 12 volt batteries, that is only necessary for arctic operations. The battery box is about 100 lbs, the shipping on it will cost the same as having a local fabricator brake you out a new 11 Ga box and weld it to the brackets.

 

[Mrgior31513]

Awesome, good thing I’m 20! Maybe I’ll understand the TM’s! I have been through the TM for it and of course it says to use the 6 volt military batteries. Those are $350 bucks a piece where I am and I can get a group 31 for $110. So I didn’t know how to convert it to the group 31. With the help of a young man in Oklahoma we got it figured out! Just looking for those parts now. I have been to Oshkosh and eastern surplus I just figured I’d see if anyone on here had anything they were willing to part with. Thanks for your help!

Good deal man, didn't realize it was a different modification. I would recommend being more focused on your posts and placing them in the right spots. Like Guyfang noted, placing a parts wanted posts is better. Starting a thread for the specific wiring issue on the modification page would have probably had more traction as well.

I was also going to note that having a local fabricator make you a box could be considerably cheaper, especially if you're willing to go with more basic aftermarket dimensions, but NDT beat me to that one.

 

[Kdubfan01]

My battery box is wired up just like yours. The huge cables are 24 volt plus and minus, and the little 6 ga ? wire is 12 volt. You can omit connecting the slave receptacle if you don't have a use for it. Use the same stud top 31s you have now. The TM will tell you to use 4 ea 12 volt batteries, that is only necessary for arctic operations. The battery box is about 100 lbs, the shipping on it will cost the same as having a local fabricator brake you out a new 11 Ga box and weld it to the brackets.

Awesome! I was wondering if that could be something that was fabricated. A young man from Oklahoma talked to me and said that my little 6 gauge wire was in the wrong place, and sure enough that’s what it was! I’ve got 2 group 31s and atleast for the summertime here that seems to be just fine!

 

[Kdubfan01]

Good deal man, didn't realize it was a different modification. I would recommend being more focused on your posts and placing them in the right spots. Like Guyfang noted, placing a parts wanted posts is better. Starting a thread for the specific wiring issue on the modification page would have probably had more traction as well.

I was also going to note that having a local fabricator make you a box could be considerably cheaper, especially if you're willing to go with more basic aftermarket dimensions, but NDT beat me to that one.

The help is still appreciated! I come from using loads of facebook groups for this kind of stuff so to see so many well organized and thought out categories and places for things was a change for me! Something that I will definitely have to work on as I get more comfortable with the site. Thanks so much!

 

[Mrgior31513]

The help is still appreciated! I come from using loads of facebook groups for this kind of stuff so to see so many well organized and thought out categories and places for things was a change for me! Something that I will definitely have to work on as I get more comfortable with the site. Thanks so much!

I'm 42 and it's taken some getting used to for me as well, but I think it's a bit easier as I'm a bit older. I'd say it's awesome that you're getting into the fray and figuring out fixes to aftermarket alterations, and I think you're on the right track and come across as very competent and capable, especially for your age. It's nice seeing younger guys getting into the mix. I would like to point out that this site alone has a ton of very competent and extremely knowledgeable guys that know a ton more than I do about these vehicles. I try and thrown my two cents in from time to time to help some people, but I would hardly call myself a military truck expert. If you want to learn: there are tons of experts and even more resources from their discussions on these forums.

Have a nice night and happy building buddy.

Also, I'm in the business of making aftermarket and custom parts for the transportation industry, so if you have any questions on those endeavors: I am very skilled in that.

 

[Guyfang]

Mrgior wrote: Starting a thread for the specific wiring issue on the modification page would have probably had more traction as well.

This is really key in getting help. Start a thread on one problem. The Title is very important. People who are M880 fans key in on a Title like, "M880 starting problem." If you always include what your equipment is, you will find that you attract people who are of like interest. So for you, this thread could have a title of, "M916 Battery questions or problems?" Short, and to the point. I think you will find lots of people willing to help and advise you. When you need parts, start a parts thread. Who knows, someone in the Forum might have just what you want. And in all probability, it will be less costly. Also, folks might just chime in with a, "I got my part at........" and give you a good place to start looking.

 

[Mullaney]

Hello all, new m916 owner here! Actually first time military truck owner aswell! I have a few questions about it. When I picked it up it had 2 very dead group 31 batteries. I ran the screw out on the injection pump and jump started it to get it 50 miles home, it did pretty good other than the lack of a working tachometer made it difficult to shift the cat trans. How are you guys wiring in group 31 batteries in these so that the dash and lights get 12 volts and the starter gets 24? A picture would be great! I’ll include a picture of what I’ve got currently in my battery box. Also what rpm are you guys up shifting and downshifting the 7155? I just fixed the tachometer so we’ve got that now! I made sure to do my best to keep it above 1100 rpm on the way home. Last thing, when I got the truck the fuel tank was rotated way up. So I loosened the tank straps to rotate the tank back so the steps were level. In the process I broke the rear tank strap anyone know where I can get one? Heck a new battery box as well while I’m at it? Mine past deteriorated! Not my first rodeo with an old semi tractor, definitely my first rodeo with a old military semi tractor! Thanks guys!

.
Welcome to the Outfit!

Seems like everybody has already welcomed you to the group and have the TM's handy. Those books will definitely help you a lot. Everything from parts numbers to troubleshooting...