Thank you for the replies!
I like the idea of putting gauges on it. I will see what Rick Allison says about that.
I really know very little about these transmissions. But starting to drink from a fire hose to learn. Correct that the trans was fine until we put the output shaft in it. And always done by the same guy.
The symptoms should lead us down the right path. Why the contamination? From the drum? It is a steel drum.
If you were meticulous and had the whole trans apart and cleaned, and the cooler and lines were cleaned as you say, then there has to be a dirt generator inside - need to find it.
