Thanks for the reply. I had thought of a brake lock up but dismissed it as I replaced all the frictions and discs when I did the trans. The actuators looked good with no signs of wear except for a slight patterning on one of the actuators which I replaced. The ramps looked smooth. I run the brakes fairly loose so as to not cause any unnecessary drag. Could the actuator hang without applying any brake? It was maybe 1/4 mile since the brakes had been applied. I was under power climbing a hill when it stopped. It was very sudden like, no slow down just a complete stop.
I have the transaxle out and the covers pulled. Aside from a very stiff 3-4 synchro, everything looks fine. I will pull the brake housings back off after a bit and see what I can find there.