Slowly working on assembly in between yard chores and a respiratory infection. Thought I would post these pictures for those who have heard of torque-lock slider syncros but haven't actually seen them.
This is the original slider out of the transmission - straight splines.
This is the new torque lock slider - undercut splines to lock in the gear engagement teeth under load and coast.
I had a little trouble with this particular syncro unit as it appears that the splines that engage the main shaft had been broached straight except for about the last 1/16 inch length (+/-) on the forward end where they appeared to take a last minute twist. It would not slide on the shaft in the required direction at all. But I turned the unit around and it slid on all the way up to the last fraction of inch and stick. I could stick a light behind it and look down the splines and see that the shaft splines were being forced over tight against the splines in the gear. The shaft splines were obviously straight. But anyway, after an hour or so of fine filing with small files and trail fitting, I finally relieved enough at the end of the slider spline sides that it slid on with a little light tapping.
I noticed one difference on the reproduction 3/4 syncro slider for the fork engagement - the originals had a stair stepped front surface and a slopped surface on the back. The reproduction is slopped front and rear - matter of fact I couldn't find anything to differentiate what would be front or rear on the slider. The hub I could determine front and rear. I'm hoping those stairsteps in the front were not for some sort of clearance issue - guess I'll find out.
Aside from the shift interlock detents the second biggest puzzle has been figuring out which direction is forward on the syncro hubs. Fortunately I removed the originals as a unit and left them that way. On the 1/2 hub the thin width bearing surface went forward and the broader width one to the rear. I found some literature to confirm this. On the front 3/4 syncro hub I found the broad bushing surface faced to the rear and the narrow surface width one to the front. This matched what I took out and the polish wear marks on it.
So, the reverse idler is back in the case and the countershaft-gear unit is resting in the bottom with the shims. Looks like next thing is to drop the main shaft back into the case, install the input and rear bearing and then the shift forks and shafts.