I'm thinking blast the screen from the bottom with solvent at high flow/medium pressure and a circular fan spray pattern like you get from a garden hose nozzle.. crud falls out the hole with the solvent. Full flush afterward. Did we ever get a definitive answer whether the screen is steel mesh or nylon? I assumed from the picture of the fresh new one it looked like stainless steel, somebody suggested it may be nylon. If it's nylon it would be even less 'sticky' than stainless and would explains why pressurizing the cooler line works as well as it does for that 1-2 km until the crud gets sucked back up. If the drain hole added is right under the pickup in the filter a plastic hose with a couple bends and a small spray nozzle (this could be fabricated with a plug on the end with small holes drilled at different angles) should be able to get right up in there. If there was a way to push fluid or solvent across that next pocket where the body of the filter sits and out the drain hole that would be even better and might make the difference between a 1-shot and having to do it repeatedly. The return line dumps out where down there?
This would be way less labor intensive than pulling the transmission to separate the bell housing.






