Originally Posted by Diesel911

If the B2 band broke it would suddenly not work. Ususally that is the same with a broken B2 Piston.

As the B2 Band wears there could be a point where it would slip. When it slips could depend on temp and other things. There is several sizes of "Dog Bone" Thrust Pins to adjust. I believe the Valve Body has to be removed to do the measuerment correctly to do the adjustment.

B2 Pistons can be sticky and the Seal I assume can wear or get damaged and an intact B2 Piston might not function properly.

From the wear pattern on my B2 Piston it looked like the Aluminum metal Bushing behind the Seal had been grabbing or binding on the B2 Piston. The Replacment Bushing is made of Nylon.
I had slipping in first issues and changed the AT Fluid and Filter and the issue went away. Less then 1 year later the B2 Piston broke.

So there is a wide range of issues that could happen individually or in some mix together.