4Star Ampli Torc help

Ill try to keep this short. 1960 4Star. Ampli torc would hold then release on its own. I could push foot clutch in and feel it re-engage. Long story short on that issue, I never used the AT.
Now comes a brand new problem and it seems very strange. I moved the tractor out of the way a few weeks ago, everything was fine and normal. Moved it again a few days ago, and it will not go into high range. The AT is engaged, and will not release and go into high. Makes no difference where the position of the hand lever is at. I should also add that now since its stuck in low, it does not slip and release.
Any help appreciated

The ampli torque is basically a simple unit When in high the clutch pack locks the unit for a straight drive thru. If you cannot get it locked in high the clutch discs probably have the internal or internal "teeth" torn off. When locked in high the complete unit rotates as one piece. When the lever is pulled back to low the clutch releases and the body of the ampli torque attempt to rotate in reverse but is locked by a one way clutch. This causes the planetary gears to rotate reducing the ground speed and increasing the torque. If the tractor stops when it is in low the one way clutch (or sprag) is slipping and needs to be repaired/replaced along with the hub it works on. By the way it should "snap in" when pushed forward, I think the manual calls for about 25 to 35 pound push. Also recommended to operate in high until the oil gets flowing around the parts or as most say until it is warmed up. When in high it will also act as a hill hold if the one way clutch is working. That can make it impossible to change gears unless you shift to low. For a better understanding get a repair manual where you can see the parts used, a service manual will help with the repair, and the operators manual will teach you proper operation and adjustment. Enjoy your MM

This post was edited by bentrims on 10/14/2021 at 01:31 pm.

What you are describing sounds like like the tabs have been sheared off of the clutch plates used to engage the TA in high range.

You can pull the round cover off the RHS of the transmission (near where the TA handle enters) and look inside and see if there are clutch tabs in the slots of the outer cage assembly.

Those tabs will fail if the tractor has been left in low range when stationary for extended periods of time. Or, if they are heavily worn.