Shift lever for the sprag

[seano11]

Has anyone ever tried to put a mechanical lever system in there so you could put it in neutral or reverse or forwards by using a lever like the high and low ? One ? Be kinda nice to get rid of this dam air shift

 

[Speddmon]

I'm sure you have your reasons, but I gotta ask anyway...Why? I think the air shift is one of the nicest things about the transfer case. Just reach up and flip a switch...instant 6x6. I don't want any more levers to have to fool with, but that's just me

 

[trooper632]

are we talking about the sprag or the air shift switch

 

[jasonjc]

I'm assuming he is talking about the air shifted sprag in the 5 ton.

 

[seano11]

YUp the 5ton sprag sorry I shoulda put that

 

[Floridianson]

I still have a problem with the air switch. Are you guys useing the switch everytime you go from a forward gear to reverse. Here is my thinking. You shut down the air to the poppets and you were in a forward gear. It is now in forward sprag and no air. Then you go and back up and it is still in forward sprag. Thought we could not do that??? There is no netrual.

 

[73m819]

I still have a problem with the air switch. Are you guys useing the switch everytime you go from a forward gear to reverse. Here is my thinking. You shut down the air to the poppets and you were in a forward gear. It is now in forward sprag and no air. Then you go and back up and it is still in forward sprag. Thought we could not do that??? There is no netrual.

Not supposed to do that, the idea behind the air cut off is on a lift tow, the rears DONOT drive the front axle, I have had the air shut off, spun the rears both directions and NOT have the front pull (this is called STUCK, needing a pull ), flipped the switch, about ran over the truck that was GOING to give me a pull

 

[Squirt-Truck]

When the air is cut off the FWD in the transfer is in neutral. It is spring centered.
TM specifies that no air in neutral.

Do you have a broke sprag spring?

 

[Csm Davis]

All of this talk of the air switch is off topic it's what I will be doing but he asked if a mechanical lever had been or could be done.

 

[Squirt-Truck]

OK, back to the original topic. No one that I have ever encountered has attempted to remove the air shift cylinder and replace it with a manual control lever. The 5-ton sprag shift just does not give much problem. If you replace it with a lever, that is a shift that will have to be manually made IN ADDITION to the forward transmission shifter wen jogging back In a forward in a tight or semi stuck situation.

IF neutral ability is what you are looking for then we are at the air switch issue.

IF LOCKED 6x6 is what you want I am not familiar with altering the T-Case to eliminate the sprag (all M-39 series and M-800's) but then we are back to Speddmon's question WHY?

 

[wdbtchr]

I have been muddling this same thought everytime my sprag doesn't work on my M51a2. It originally worked only in reverse. Rebuilt poppet valve, replaced poppet valve, decided the air cylinder was bad, tried to rebuilld, currently looking for a new/servicable cylinder because the cylinder was rusted out.

I put a 1/4" valve in the air supply line to cut the air loss through the aircylinder when not off road(takes the place of the air switch). I'm leaning further and futher toward a manual shifter. That's why I'm thinking that I've already spent too much time fighting with the air shifter problem.

Generally I like to have things working as their supposed to but . . .

 

[bigford]

One possibility but it's ugly... Drill a hole in the cylinder end plate and extend the shifter rod out, put a clevis or rod end on it and connect to a lever. Opportunities abound for mess-ups though. I need to replace the sprags in mine because I have a manual air shift set-up in my F700 as a back-up to a solenoid off the transmission reverse switch. Forgot it was in forward and backed up.

 

[doghead]

So, Why?

 

[jcappeljr]

I have had a lot of problems with the 800 series air shift sprag.Thats why I switched to the 900 series trucks.You never know when they are going to work.

 

[mbent1911]

Can you use a 900 transfer case in an 800 series truck ?

 

[mbent1911]

2 more ? does the sprag go bad are most of the problems with the poppet valve?
Can the sprag be change without pulling the Tcase?

 

[seano11]

I'm thinking of just swapping out transfer cases to a 900 series

 

[sandcobra164]

I think the air shift transfer case in an M800 series is solid as it. The shift mechanism from forward to reverse is a very simple well thought out design. To see if it works, start truck, build air, shut truck down, move shifter from any forward gear to reverse. You should notice a nice pffft of air and a nice solid clunk. If you're not hearing both, you have some work on your hands. With the M818 in my yard, I oiled the "sprag shifter" via the airlines and still have a problem. I took the transmission tunnel sheet metal off and noticed somebody had plugged the vent line on the transmission poppet valves. Removed the bolt, Transfer Case pffting and clunking as it should and no further issues with this truck.

 

[seano11]

I think the air shift transfer case in an M800 series is solid as it. The shift mechanism from forward to reverse is a very simple well thought out design. To see if it works, start truck, build air, shut truck down, move shifter from any forward gear to reverse. You should notice a nice pffft of air and a nice solid clunk. If you're not hearing both, you have some work on your hands. With the M818 in my yard, I oiled the "sprag shifter" via the airlines and still have a problem. I took the transmission tunnel sheet metal off and noticed somebody had plugged the vent line on the transmission poppet valves. Removed the bolt, Transfer Case pffting and clunking as it should and no further issues with this truck.

I have replaced every bloody part of the system but the clutches and it still doesn't want to work right

 

[Stan Leschert]

Where Sean lives, things are prone to freezing.

Right now they are covered in white stuff. Not as bad as Alaska, but rubber doesn't last long.
Unless your air dryer is up to standards, and the truck is ran frequently, you have problems.

I wouldn't do the manual bypass, but that's just me.