Need transmission help 1955-56 IH 300 Utility

[prowrench78]

I am trying to help a friend of my dad's. He owns a 300 Utility and the transmission seems to have locked up. We have removed the lid to the transmission and rearend. Upon inspecting the gears and shift forks, I noticed 2 things. 1- the leading edges of the gears are worn like they had been engaged with out the clutch fully depressed. How a flywheel looks when a starter bendix has not fully thrown out. 2- The center shift fork detent area of the center shift fork is worn down and the ball falls too far down and gets stuck. With the transmission open we could not move any of the sliding gears, even when rocking the tractor. Seemed to be locked up. PTO shaft still spun while tractor running, but when clutch is released tractor would bog down and try to die out. Does anyone have info on common causes or where to begin to diagnose the problem?? Tractor is in field with hay down.
Any diagrams of proper gear placements such as neutral position of gears? Any info would be super- appreciated!! Thanks in advance.

[prowrench78]

I forgot to mention it has the Torque Amplifier feature also. Don't know if that makes a difference?

[Bob McCarty]

I'm not familiar with the 300's, but if you click on "quick links" upper left and then on "International 300, 350", there is a service manual for the tranny. I don't know if that will help any or not though.

[iam2]

P-W: did you have any luck on this tranny, I sure would like to follow what was the out come!