6x6 engaged ???? Help

[Therapydoc]

1989 M923a2 that’s new to me. Trying to figure some things out. This lever I assume is to engage the 6x6. Currently it’s in down position which is high. There’s a neutral but I’m guessing that completely disengages the drive train ? Am I correct on that.

Also is there a way to dim the lights or is high beam the only option? I assume black out mode disables all head lights

Thanks in advance Guys

 

[BKubu]

That is the transfer case lever. The lever that engages the front axle is in the second picture you attached (below and to the right of the light switch).

Regarding the headlights, there is a button on the floor to the left as you are sitting in the driver's seat that turns on and off the high beams.

 

[Elk1111]

The lever on the floor also engages the 6x6 when pulled up and put in low unless your truck has been modified in some way.

 

[M813rc]

Can I hazard a guess that you are not familiar with how to find the operators manual? It will explain all of the controls in detail for you.
That and the maintenance manuals are all available here -

Updated TMs TBs MWOs for the M939

A couple of these may be repeats but I'll include them anyways in the interest of trying to make applicable TMs, TBs, LOs, and MWOs easier to find. There are only a couple missing and I'll notate those in hopes that someone else may have them and can link them as well. Please understand that...

www.steelsoldiers.com

Go down the list and find TM 9-2320-272-10
Dash 10s, as they are called, are the operator manuals for military vehicles.

Cheers

 

[Elk1111]

Take a good look at the starting and shutting off sequence on your switches also. If done in the wrong sequence you can fry your PCB box.

 

[Valley Rock]

Yes the long floor lever in between the seats is neutral halfway up, which does indeed disengage the drivetrain .

Yes blackout turns off all headlights and turns on a little baby light on the front that you can barely see .

The dimmer switch is on the floor over to the left where it should be, like all vehicles had them back in the day when men were men and vehicles were made out of Steel in the USA .

I hope you spend some time with this vehicle either on private property or off-road before you take it out into the streets and end up on the news

They're awesome fun trucks, enjoy !

 

[Therapydoc]

That is the transfer case lever. The lever that engages the front axle is in the second picture you attached (below and to the right of the light switch).

Regarding the headlights, there is a button on the floor to the left as you are sitting in the driver's seat that turns on and off the high beams.

ok I was thinking that was a differential lock.

im not understanding What your saying regarding the yellow lever. I understand it’s the front drive tires. So currently being in high that is engaged in 6x6 right ? So if I put it in neutral, is that where I should do the most of my driving around town and all ?

 

[Therapydoc]

Can I hazard a guess that you are not familiar with how to find the operators manual? It will explain all of the controls in detail for you.
That and the maintenance manuals are all available here -

Updated TMs TBs MWOs for the M939

A couple of these may be repeats but I'll include them anyways in the interest of trying to make applicable TMs, TBs, LOs, and MWOs easier to find. There are only a couple missing and I'll notate those in hopes that someone else may have them and can link them as well. Please understand that...

www.steelsoldiers.com

Go down the list and find TM 9-2320-272-10
Dash 10s, as they are called, are the operator manuals for military vehicles.

Cheers

I appreciate that.Is the 923a the same as the 939? Sorry fellas this is a whole new world to me. Haven’t had time to dive much into this site to find everything with ball schedules and all.

 

[Therapydoc]

Take a good look at the starting and shutting off sequence on your switches also. If done in the wrong sequence you can fry your PCB box.

the fire house I bought it from told me to turn the battery on down by the seat first then the upper battery power switch on dash and then the start lever is just below that one on dash.

to kill it, I do it all in reverse order. Does that sound correct ?

 

[Therapydoc]

Yes the long floor lever in between the seats is neutral halfway up, which does indeed disengage the drivetrain .

Yes blackout turns off all headlights and turns on a little baby light on the front that you can barely see .

The dimmer switch is on the floor over to the left where it should be, like all vehicles had them back in the day when men were men and vehicles were made out of Steel in the USA .

I hope you spend some time with this vehicle either on private property or off-road before you take it out into the streets and end up on the news

They're awesome fun trucks, enjoy !

driven plenty of tractors, dozers and dump trucks in my days so not afraid of it in the least. Everything is just built different and I enjoy understanding the mechanics of how everything works and there’s no better place to learn than From you all that have the experience

 

[M813rc]

I appreciate that.Is the 923a the same as the 939? Sorry fellas this is a whole new world to me. Haven’t had time to dive much into this site to find everything with ball schedules and all.

The 939, 939A1, and 939A2 have some differences (engines, tires, CTIS, etc.), but most of the controls are the same. Take some time to go through the -10 manual, it will explain the differences, the similarities, where everything is, and how everything works. It is a great reference source for guiding you through. Once you know what the things do, and the military way of doing it, its all fun from there.
We'll be happy to help answer questions as you go along.

Edit to clarify - M939 is the type designator for a series of trucks. M923 (cargo), M931 (tractor), etc. are all different models within that series. There are also subtypes - M923 has the NHC engine and 11.00 tires, M923A1 has the NHC engine and 14.00 tires, M923A2 has the 6CTA engine, 14.00s and CTIS. M925 is an M923 with a winch. And so on. Clear as mud?

Cheers

 

[Elk1111]

That order is correct on the switches.

If the yellow lever is down the truck is in high. If the lever is all the way up it’s in low and should also be in 6x6. If you want 6x6 in high you have to flip the switch under the lights to “in”.

Very important!!! Absolutely do not use reverse if the truck is in low. It will grenade your transfer case.

 

[Therapydoc]

That order is correct on the switches.

If the yellow lever is down the truck is in high. If the lever is all the way up it’s in low and should also be in 6x6. If you want 6x6 in high you have to flip the switch under the lights to “in”.

Very important!!! Absolutely do not use reverse if the truck is in low. It will grenade your transfer case.

thank you that’s what I needed to know. Makes sense now.

 

[Mullaney]

thank you that’s what I needed to know. Makes sense now.

.
Another small thing - just so you know - the 939 Series of trucks includes what you have and the others that look similar. A 936 for example is the "wrecker variant" in the 939 Series of trucks. Most of the things in the cab are the same in that line of vehicles. The -10 (Dash 10) TM (Technical Manual) is the same for all the trucks in that series + the stuff like the wrecker boom section or the dump bed on the 930.

More information below with pictures:

M939 series 5-ton 6×6 truck - Wikipedia

en.wikipedia.org

 

[M813rc]

Thanks, Mullaney. I realize I didn't clearly answer that part of his question... I edited my post for future clarity.

Cheers

 

[silverstate55]

The front axle is engaged by an air piston on the transfer case, flip the switch below your light controls to engage front axle drive. The transfer case lever selects between Low, Neutral, and High ranges.

Blackout drive provides a very small beam of light intended for assisting drivers while wearing Night Vision Goggles, the old Passive (green) types. Please don’t try this on public roadways….

 

[M813rc]

Two things to keep in mind when operating these trucks -

When starting/stopping the engine, always top switch on, bottom switch on; then bottom switch off, top switch off. Doing the switches in the wrong order can fry the protective control box.

And don't use reverse in low range, unless you have a yearning to see what your transfer case looks like in bits under the truck!

Cheers

 

[Defcon-1]

Two things to keep in mind when operating these trucks -

When starting/stopping the engine, always top switch on, bottom switch on; then bottom switch off, top switch off. Doing the switches in the wrong order can fry the protective control box.

And don't use reverse in low range, unless you have a yearning to see what your transfer case looks like in bits under the truck!

Cheers

To note on the switch order, I actually took off and painted the battery switch BRIGHT ASS RED as a visual reminder to not kill the engine with that switch first lol.

Edit: I was actually going to do a "glow in the dark" green fluorescent to distinguish between the ignition and battery switch at night, but that stuff is expensive and BAR (Bright Ass Red) is also easy to see at night lol. But yeah, do yourself a favor and make a habit of doing it in sequence somehow, don't let anyone drive the truck either that doesn't know about it too. Battery switch off should always be the last step in securing the cabin / leaving the truck, unless you have tons of extra $$$ and time you need to spend somehow lol.

 

[Valley Rock]

Ya know I'm absolutely certain that you guys are correct about the importance of the order of turning off the switches, however my grandson is often up in the cab of the truck when it is running and manipulate those switches in every manner possible and I've never had a problem .

I'm not saying I recommend it, but just letting you know ...



Of course meow I've jinxed myself