Eliminating air srag on 5 ton!!!!

[atvcat33]

I have a idea..... Couldnt you block the air lines going to the sprag, eliminate the sprag, and plumb new lines to the transfer case, with a air toggle simular to a duece, i was thinking this might work, knowing there is no electrical engagement just air.

Some people say you would half to flip it in and out for reverse and shifting gears and have to toggles, but i dont think so...

I have a 818 and a m62 both with sprag problems and want to eliminate it all together, just looking for another opionion

 

[jasonjc]

NO

The sprag is not air, the shifting of it from fwd to res is air. To eliminate it you would have to regrear the t-case, like they did on the deuce t-case.

 

[quarkz]

Oh, your talking about the sprag.
I read your title as eliminating drag on a 5 ton.
And I think you have to get up to +60mph before drag becomes a concern.

Nevermind.......

 

[jwaller]

cannot be done. there is nothing electrical on the sprag or transfer or transmission anyway.

you can turn the air off to the sprag so that it won't work but then you won't have 6wd. there is no good way to eliminate it.

 

[atvcat33]

what exactly tells the t-case to go into 6x6, and take it out of 6x6???, mine never worked from day one so i dont know how they even work all together

 

[area52]

this is my understanding of the sprague, sprag transfer case-

It is basically a clutch operated t-case based off of the front and rear wheel speeds. when the rear wheel speed is approx. 7% faster than the front, (i.e. slipping) the clutch engages and sends power to the front axle.

The valves on the transmission "tell" the transfer case whether or not its in forward or reverse gear.

 

[atvcat33]

hmmm.... interesting, sounds like a complicated mess, i have a oshkosh mixer t-case, i think ill take some measurements

 

[nk14zp]

Steel Soldiers::Military Vehicles Supersite - Search Results

 

[73m819]

The sprag works on a demand bases, the sprag is a over running clutch, the gearing in the xcase over runs the front,, the way it's set up is as all the wheels are turning, the xcase inside senses a bit slower rpm, when the rears spin, then the xcase senses the rears are turning faster then the front which in turn engages the front wheel drive.

There have been many,many threads on the 5t sprag and the air valves along with the shifting cylinder

As a side note, my old 52 m52 and my 819 never gave me any sprag trouble.

When you go from forward to reverse and reverse to forward, do you hear the air release and the xcase sprag unit shifting ??????

 

[jasonjc]

Think of the sprag this way as a rachet wench. If you pull on the handle it truns the socket. But if you trun the socket faster than the handle it rachets. The truck going down the road truns the front wheels faster than the t-case truns them. Now if the road does not trun the wheels then the t-case will.

Does this make any sence??

Almost forgo. The air shifts it from fwd to rev, just like the knob on top of the rtchet.

 

[Bob USNR]

I have an M817. Accidently, I stopped and let it roll backwards... the driveline "wound up" and stopped the truck. Initially I thought a trans had jammed but quickly realized what had actually happened.
My point is "I" would NOT override the automatic release of the front axel in reverse until I was absolutely sure there is no danger of killing an expensive gearbox... or two.

e

 

[jatonka]

It would require what has been known as a "REB" kit, replaces the whole sprag with 2 new gears set up to run same ratio as the rear output. And an engagement handle kit to choose lock or free for the front axle. Memphis did it years ago with the deuce sprags, the parts are gone, they won't build any more due to lack of interest, not profitable enough. The 5 ton gears would be a lot more expensive. take it from there. Isn't there one really wealthy soldier out there who wants to give it a go? JT out

 

[atvcat33]

my trans makes the air sound going into reverse but not when it goes out. i removed the driveshaft due to it engaging on me all the time and causing the truck to make a abrupt pull left or right for a second and a big bang??????

when i removed the front driveshaft the shaft had some pressure on it, made a clunk in the t-case when it actually fell down, i then was able to spin the drive adapter on the t-case with no issues, the truck would only act funny in 1-3 gears not in 4 or 5, also acted funny in lo range, i now am having some trouble getting it from low to high range on the fly

 

[Floridianson]

cannot be done. there is nothing electrical on the sprag or transfer or transmission anyway.

you can turn the air off to the sprag so that it won't work but then you won't have 6wd. there is no good way to eliminate it.

Respectfuly I am still in my mind trying to figure how this mod works. I know the Goverment did it and some on the board have done it and say it works.
What puts the piston in the middle pisition. If there was no air seems like the piston would be in the last pisition it was left in. The pistion is a tight fit in the cylinder so what would put it in the middle pisition? Does the lack of air push it to the middle pisition? Thanks

 

[73m819]

James, I can not answer that question, but I KNOW it WORKS because you can get stuck if the air is cut off and will keep you from going on a recovery trailer if your third axle is unpowered

 

[73m819]

]my trans makes the air sound going into reverse[/B] but not when it goes out. i removed the driveshaft due to it engaging on me all the time and causing the truck to make a abrupt pull left or right for a second and a big bang??????

when i removed the front driveshaft the shaft had some pressure on it, made a clunk in the t-case when it actually fell down, i then was able to spin the drive adapter on the t-case with no issues, the truck would only act funny in 1-3 gears not in 4 or 5, also acted funny in lo range, i now am having some trouble getting it from low to high range on the fly

Sounds like you trans forward air valve is bad or the xcase air cylinder is worn and by-passing, there are a few GREAT 5T SPRAG threads on site, search is NOT my FRIEND, other wise I would get a link for you

"hmmm.... interesting, sounds like a complicated mess, i have a oshkosh mixer t-case, i think ill take some measurements "

This would be a great mod if it will work with the outputs on the right side, all the shifts are air COOL, the only thing is if it is for the m62, check to make sure the the xcase pto will work or if you can get one that works, the E brake can be worked around.

 

[73m819]

Just a thought, would a 916 transfer work in a m54/809 series, if so this would be great, both air shift for H/L and front drive

 

[Barneyszoo]

If someone was to pull a stuck veh. would it be best to pull in reverse or forward?

 

[wjruth]

Forward - the gears are designed for greater strength in forward and not reverse. They are work hardened on the forward / drive side, the backside is the coast side.

 

[Floridianson]

Just a thought, would a 916 transfer work in a m54/809 series, if so this would be great, both air shift for H/L and front drive

Good thought and have talked about it with a friend. Would the ratio work out or do we need to change out trans. to? No high and low though.