Well I'm 0 for 2 on a 5-Ton with working 6x6

[CapHap]

Hey guys, well after buying a 68 M818 and having no 4x4 (discovered it was leaking air around the cylinder and have since ordered the kit for it) now the 72 m817 I just bought the front axle will not pull either! No air leaks, and the poppet valves are sending air to each side of the cylinder. So I'm assuming the Sprag clutches are gone in the Xcase...... How hard are those to change?!? Are these trucks just know for 4x4 problems or is it just my luck?? I would think with the army wanting to simplyfi everything, they would just have a mechanical Xcase that just locks and unlocks, but NO lets rely on air cylinders and valves and clutches.... That seems full proof... I bought these trucks for some good heavy duty 4x4 trucks to use around the farm, even bet my father they would work better than these new trucks... So far I'm loosing
And to Top it all of we finally get a good snow in Arkansas and no chance at using them...

 

[commandojeff]

The 4x4 always works...?

The reason we can buy these trucks is because the military already got their use out of them. Did you really expect to get a truck that has zero issues?

 

[rrrr]

I'm not familiar with the 8 series trucks front axle engagement. Use the search function in the 5 ton section. I'm sure others have posts that could be helpful. In addition the Technical manuals, TM's, are available for download here on the forum. Hang in there. It might take a little bit but you'll get them going. Good luck.

 

[CapHap]

No, of course I expect there to be issues, But since BOTH of mine are having the same problem I was just wondering How frequent this issue was. I probably need to restate my question with a Lil less whining on my part. Has anyone ever replaced the Sprag Clutches in a 5 ton Xcase and if So any quick details on the job would be helpful. If this project is a Huge undertaking ill just sell them...

 

[swbradley1]

There are at least two threads on the M809 series sprags. I was looking at them this morning.

 

[seano11]

I've rebuilt the whole system only thing I have left to do is change the clutches. Might happen or I might put a transfer case out of a 900 into it. Someone had also said Memphis made a delete kit

 

[CapHap]

Well after laying under the truck for most of the night I have discovered the poppet valves on the 817 are not working correctly. Removed the floorboard and took the lines loose from the valves that feed the cylinder so I could start the truck and shift between neutral and reverse to see what the air was doing. In neutral the air is pumping out of the rear valve, when I shift into reverse the air starts to pump out of the front valve but never stops pumping out of rear one. So looks like I'll be ordering a new set of valves for the ole girl and see what happens. I took the air cylinder apart also and it looks clean and the gaskets are in good shape (I think) so hopefully this will fix it. I have searched on here for a form discussing where to find the info on how to change the sprags, with no results. If anyone could post a link that would be Greatly appreciated!

 

[CapHap]

Well little report on my m818. after putting new poppet valves and rebuilding the air cylinder on my Xcase and flushing my Xcase with diesel fuel to free up the clutches, i now have a working 6X6!! A huge thanks goes out to 73m819 for putting up with this kid and his new toy! I ended up selling the 817 to a friend of mine so no updates on that one. I did steal the winch off it before I let it go though!

 

[rrrr]

Great job ! There are always issues with these trucks when you get them. I don't know of anyone that hasn't had to do a few things to get them in good shape.
Now you'll be the expert we go to when we have these issues.

 

[swbradley1]

Well little report on my m818. after putting new poppet valves and rebuilding the air cylinder on my Xcase and flushing my Xcase with diesel fuel to free up the clutches, i now have a working 6X6!! A huge thanks goes out to 73m819 for putting up with this kid and his new toy! I ended up selling the 817 to a friend of mine so no updates on that one. I did steal the winch off it before I let it go though!

That's the second time I've heard about the diesel to free up the clutches a little. When Gimp and I got my 813's air pack fixed the front axle would not engage until after a few attempts. When I tried after the first big snow this year I could not get to engage and I'm guessing mine need a diesel laxative too. Or maybe I just need to get it out and use them more.

Thanks for the updates.