One track doesn't want to pull at times. D5 94J

Hi all. I have a interesting situation that happens occasionally that I'd like thoughts on. Dozer is D5 direct drive. What happens is that sometimes when pushing a big load one track does not pull/spin. If i change direction and go forward again both tracks spin. I have tested the steering clutches by pulling them back one at a time and the appropriate track disengages and resumes. It seems to be isolated to the left track, turns to the right moving forward are not possible. So instead I do a reverse turn to the left to accomplish the right turn. Seconds later forward left turn works with no issues. Could the left steering clutch be engaging on it's own? Transmission issues?

You are describing either
Left steering clutch is weak and slipping when it’s carrying all the load so tractor stops when trying to turn right instead of turning when you pull the right clutch
Or
Right steering clutch is not disengaging or brake doesn’t work, so tractor continues pulling in a straight line instead of turning right when the right clutch is pulled.

Which is it?

[quote="ccjersey"]You are describing either
Left steering clutch is weak and slipping when it’s carrying all the load so tractor stops when trying to turn right instead of turning when you pull the right clutch
Or
Right steering clutch is not disengaging or brake doesn’t work, so tractor continues pulling in a straight line instead of turning right when the right clutch is pulled.

Which is it?[/quote]

I should have been more clear. It seems more like tbe first scenario except I have had it happen on flat ground with no load. For example, pull right steering clutch and trying to go forward and nothing happens. Switching to reverse with right steering clutch still pulled and it goes backwards. With right steering clutch still pulled try forward again and it spins right with no issues.
I assume it works with friction plates like a main clutch?