TM -20 help

[5tonman1971]

Well my 813a1 keeps getting stuck in 6 wheel drive

sometimes it will engage and then will not disengage and there is no air being released when I shift in to reverse. I'm looking they the -20 but can not find the sprag or front axle endgame by section can someone please direct me to the right section

 

[doghead]

Look at the front cover of the TM.

Troubleshooting is in Chapter 2.

It is just after the PCMS.

Your issue is likely a sticking shuttle valve.

There should be plenty of good threads on this(how to clean and lube it.

Proper shifting is also required.

One old trick is. sit still with truck running and air pressure up. Shift somewhat rapidly between 1st and reverse(keeping the clutch depressed) and back about 20 times. This often gets the shuttle valves unstuck. Adding lube helps as well.

 

[5tonman1971]

Thank you sir, when the temps get back above zero I'll go out and try this.