Air actuated front axle

[32degrees67]

I just looked at a lot of four deuces all of them were late sixties models but only one had the air actuated front axle. The rest seemed to be locked in full time is this normal it seemed to be done at a depot. These trucks were used in Desert Storm last then came back state side. Is it common for the military to remove the actuator.

 

[ctmustang]

Not all were airshift and they used a sprague transfer case instead. When the front spin the transfer auto locks into all wheel drive. Some people don't like the sprag but I have never had a problem with either and will continue to own either with no concerns. Maybe someone else will chime in about non air actuated.
CT

 

[wreckerman893]

They (the three) are prob sprague trucks....they are not full time 6 wheel drive...the sprague allows the front axle to kick in when the rear wheels start spinning.
It's unlikely that the Army removed the air actuators as that would prevent using the front wheel drive capability of the truck.
It was not unusual for Guard and Reserve units to still have sprague trucks in their inventory.

 

[32degrees67]

If these are not sprage would this be bad on the axle for highway use. Just short distance. One of the trucks had type stenciled in 45mph only.

 

[Capt.Marion]

It's not a matter of whether they're SPRAG (that's how you spell it) transfer cases or full-time 6 wheel drive.

Trucks either had the Sprag or they were upgraded to air-shift transfer cases. Either way, none have their front axles engaged full time.

Air-shift, you flip a switch and it uses compressed air and a piston to engage the driveline to the front axle.

Sprag, the design of the gear-system inside the transfer case senses when the rear axles slip (spinning but without resistance) and engages the driveline to the front axle.

EDIT: When the Sprag transfer case is adjusted properly, it works beautifully. The Air-shift trucks are more desirable to some because they are easier to work on and simpler. Either way, the trucks should be fine to drive on the highway, as long as the front axle isn't engaged. Unless the Sprag trucks have damaged transfer cases (unlikely), they should be just as fine as the truck with the air-shift case. The 45 MPH stencil is primarily because they didn't want drivers going too fast (60 MPH) and blowing engines, etc... I think 45MPH is also the standard convoy speed.

 

[32degrees67]

Thanks guys good info next time I go over to them I'll break the system down better. Today was a bad day hot and yellow jackets all over the trucks.

 

[32degrees67]

Oh yeah forgot on some of the trucks there was an electric toggle switch were the front wheel drive switch was. Flip it and it made no noise like a regular air switch could this be an electric type.

 

[32degrees67]

This is an image of the cab of the truck the switch is on the bottom of the dash on the far right. What is that it has nothing imprinted on it.091.jpg

 

[area52]

Looks like the heater on/off switch.

 

[SilentSpeedy]

I need a rebuild kit for the air cylinder on a 5 ton, anyone know the part number for that? I am running out of keywords, here and on google.

 

[Bob H]

Looks like the heater on/off switch.

yea, what he said.

 

[roger-wilco-66]

Sprag, the design of the gear-system inside the transfer case senses when the rear axles slip (spinning but without resistance) and engages the driveline to the front axle.

Maybe I'm wrong, but I do seem to recall from studying the T-case that the airshift has the same automatic mechanism for engaging the front wheels. The air-actuated t-case does not give you a full time 6x6 when the air switch is flipped. It merely enables the same sprag clutch. This is the difference between the sprag t-case and the air t-case. Sprag version is always on auto-6x6, while in the air version the auto-mode can be disabled.

But maybe I stand corrected here.

Cheers,
Mark

 

[gringeltaube]

No Mark, look at the diagram below... no sprags, no extra pair of gears like the T136-21 has.

When the clutch is engaged it is a true 6x6 locking all driveshafts together at equal speed to all axles/wheels.

G.

 

[popacom]

I too am not 100% sure but I believe you will find that the sprag clutch trucks can only engage
the front axle in reverse and "BULL DOG" low. Where the air shift trucks can engage the front
axle in the upper gears also. But I am open to corerection on this as it has been a minute since
I ran these trucks but have owned both types. I do know with the sprag trucks you CAN get
them "wound-up tight" or in a bind and it can be a somebiatch to get them to roll!!!
(BEEN THERE <DONE THAT<GOT THE T-SHIRT THREW IT AWAY LOL)

popacom / BILL in KY.

 

[gringeltaube]

I too am not 100% sure but I believe you will find that the sprag clutch trucks can only engage
the front axle in reverse and "BULL DOG" low..................................

Read this: http://www.steelsoldiers.com/deuce/32130-shifting-sprag-tc-how-works.html

G.

 

[two.fiveM35]

I know this thread started in July but I wany to add my 2 cents. I don't think you can permently lock it in 6x6, you wouldn't want too if you could. I wouldn't drive well on pavement or steer well. Your issue may be what I discovered on my deuce. My deuce originally came with a sprag, but at some point they put in a air shift transfer case but didn't install any air lines. Look at the transfer to see if it has a air shift cylinder.

 

[gringeltaube]

........................ I don't think you can permently lock it in 6x6, you wouldn't want too if you could. I wouldn't drive well on pavement or steer well..

Agreed if you mean the sprag-TC T-136-21, it does work (fairly) well off-road AND well on-road!

As for the Air shift TC (T-136-27) YES you can have it engaged (= locked = true 6x6) for as long as it gets sufficient air pressure, 50psi or more.... and NO, you shouldn't drive on pavement that way.

Look at the transfer to see if it has a air shift cylinder.

G.

 

[Floridianson]

I need a rebuild kit for the air cylinder on a 5 ton, anyone know the part number for that? I am running out of keywords, here and on google.

Call Memphis equiptment they know what you need and have some in stock. I just got three kits.