Cat D6H busted transmission cooler

I have a d6h for about year now an has done a great job. But recently the transmission oil cooler busted an filled the trans up with water.. I replaced with cat reman ,changed oil , cleaned, three screen's an filter several times, now oil heats up after about 3 hours pushing..water temp stays consistent, ive checked torque relief an inlet pressure an are in line, did stall test an pulled out scavenging screen an got about 1.5 gal out, took off cooler line's an checked for restriction, just dosnt seem like oil is flowing thru cooler, wondering where it go's after it leaves cooler into transmission is there anything I can check there.. thanks for any help you can offer

Cat D6H busted transmission cooler