M809 series transfer case stuck in neutral

[chrsbb19]

Ok so i searched the forums for about an hour and i didnt see anything about the transfer case being stuck in neutral, so i need some advice.

1. How in the hail does it get stuck in neutral
2. i tried rolling the beast while attempting to move it into hi and low. no joy
3. lifted front right axle and spun the tire as i attempted to place in gear, again no joy
4.rolled backwards and attempted to place in gear, no joy again

a. by this point i am pretty frustrated
b. i am going to try to fill with diesel and tow it around for a while to clean it up, hopefully it will work but im not holding my breath.

 

[gimpyrobb]

So the motor runs, and you can run through the gears in the trans, but because the Tcase is in neutral, you go no-where?

I'd look under the truck at the shifter and see what was going on. Has it ever worked? Any history? or is this a new truck you know nothing about?

 

[chrsbb19]

So the motor runs, and you can run through the gears in the trans, but because the Tcase is in neutral, you go no-where?

^Yes^


Everything is hooked up and works, she rolls fine and the linkage moves. I just cant get it to slide the linkage in or out.

The M816 has been in the Hawaii national Guard from 1960ish-1990ish, was moved to Barbers Point for flightline duty until the control tower was finished in 2002. I was told it was used in a film after or during, i will find out what title the movie was.

 

[gimpyrobb]

I'd try taking the linkage free from the sifter and see if its not adjusted right. Next I would see if the air shifter for the sprague moves in and out.

 

[chrsbb19]

http://www.oshkoshequipment.com/products/detail/63/47/Transfer-Case-Air-Shift-Cylinder

Is this the air shifter?

 

[gimpyrobb]

It certainly looks like it!
I would get in there and look at the one on the truck first. It could just need some gunk cleaned out, or the poppet valves on the transmission need lubed. Its hard to say whats going on till you get in there and look around a little.

 

[chrsbb19]

I replaced the poppet valves on the tranny, it seems to be attempting to send air to something but is blocked. the purge is leaking but its new, i wonder if the declutch is seized but would that keep it from going into a gear?

 

[gimpyrobb]

I haven't dug into mine yet to know much more in-depth. I know my tcase goes in hi and low range, and I know my air shift cyl goes in and out.

My front wheel drive does not work, so I will be tearing into the tcase, or swapping it out. I haven't had time to look into it any farther.

 

[chrsbb19]

My front wheel drive does not work

I was reading a post on here the other day saying that there was a gear that gets stuck and the simple solution was 6 qts of diesel and a 15min or so drive and 60% worked.

I will defiantly take some photos and post them on this thread, hopefully it works and i will try the diesel my self for the gunk.

 

[Floridianson]

Yea I would remove the air cylinder and I bet you will find the two seals shot. I did a post about removing it the easy way. The only hard part is getting the safety tabs bent over on the 4 bolts that hold it to the transfer case. When I do mine I air up the truck and put it in reverse and shut off the truck when still in reverse. Then I air down the air tanks and the air cylinder will be in the rear position. Your air cylinder is not moving so this might not help you so skip this. Once you get the cap off you will need to take a 5/8 socket if I rember right and unscrew the nut that holds the cylinder onto the sprag shaft. If you get lucky the cylinder will come off. If not then you need to take a nonmar type belt wrench and unscrew the cylinder off the threads that are on the sprag shaft.

 

[73m819]

The sprag has NOTHING to do with SHIFTING between high and low, sounds like the shifting rod is froze if it WILL NOT move., in the HI environment, things rust real quick, take the linkage loose so you have just the shifting rod sticking out, PB BLAST the chit out of where it comes out of the case, let it soak, repeat a few times, after each soak, smack the shift rod with a hammer, not only to go in but on the sides, the idea is to put a shock to the shift rod.

BEFORE doing the above, pull the drain plug to see if water comes out, if oil, good, water, bad. IF oil, tow the truck at about 20 mph for about 20 miles to get oil to the top of the case and get oil into everything. the sprag transfer has a synco for shifting into high/low and low/high, the transfer WILL NOT shift if the synco does not move. doing the above will help getting the synco to move. If you have oil, thin it with a gal. of diesel, put new oil in after the transfer starts working . IF YOU HAVE WATER which equals RUST, drop the transfer, then go from there.

 

[Floridianson]

Right Ron my fail to read tread think and post. Good sign of getting to old.

 

[jasonjc]

There is a set screw that holds the shift fork to the shift shaft. If it backs out then it will not shift. If the shaft is moving in and out like it should, check the set screw. You can see it thought a cover on the side of the case with it in the truck. I had this happen to me.

 

[73m819]

FTF would be glad to come and take care of your transfer case issue, we are AVAILABLE for on call world wide.

 

[chrsbb19]

So an update. The decluch air valve works beautifully, i soaked the living mess out of it all day and rapped on it with a hammer. Still won't budge, I saw an access panel on the side of it. I want to open it up and see if I can get it free from there. Also the movie my M816 was in is the tears of the sun, they snapped of my front winch cable playing with it. I'll take some pictures of the transfer case and post on this thread of my progress as I make it. Lol

 

[chrsbb19]

FTF would be glad to come and take care of your transfer case issue, we are AVAILABLE for on call world wide.

But how much would that cost me

 

[73m819]

but how much would that cost me

cost plus

By the way FTF stands for Five Ton Fixer

He states in post #3 that the shift rod is not moving in/out of the case, so either the shift rod if frozen, detents are frozen, or the synco is frozen, what ever is the issue is, it sounds like a inside the case issue, which leads me to think RUST from the salt air and the truck sitting for a length of time. FILL the case as full as you can get with diesel, automatic trans oil. run the engine with the trans in 3rd gear at about 650 rpm while the truck is being towed WITH A TOW BAR for about 20 miles at 20mph, this will sling oil up to the input shaft, while the input shaft is working, hoping this will force the slung oil into the detents, syncos, , shift rail/collar

AGAIN BEFORE you do anything , pull the drain plug and see what comes out, if oil put the plug back in and continue with the program, if water or SLUGE, GOOP, METAL, or any other non good transfer CRAP, go to plan be , DROP THE TC,

 

[gimpyrobb]

By the way FTF stands for Five Ton Fixer

I thought there would have been a "U" in there somewhere, after you blew out that front tire!

 

[jasonjc]

Opps, I seen where he say the linkage moved but missed the part of the shifter shaft not going in and out.

 

[elkhtr]

Opps, I seen where he say the linkage moved but missed the part of the shifter shaft not going in and out.

Still good information for someone else.