plumbed in the Hayden cooler, which I have mounted in front of the radiator & condenser. I have the return from the radiator going into the new cooler, and then the output of the cooler barbed into the return line to the trans. Two coolers really should keep thing thing on ice I hope. Also added a quart. Drove around for around 45 minutes, mostly at 60ish mph, and it never got over 165. Granted it was nighttime and only 85 degrees. But even through the neighborhood at the end of the drive the temp held, whereas it had been shooting up. Should be around 100F the rest of the week, so I'll be sure to get a decent length test drive in the real heat to see what the trans temp does under more intense conditions.
The only thing I can figure on why it runs hotter now after the overhaul than before is that the new clutches are thicker and are generating heat as they pass over each other due to less clearance. I checked the clearances and they were within spec though. I still don't have the TV cable adjusted perfectly, shifts to 2nd a smidge too soon...I guess it's possible the line pressure is too low and is allowing some extra heat to build up? I'm just spitballing at this point.
If the temp holds at 180 in the heat with the cooler in place, I'll call it good. It never ran at 200 before so if I get north of 180 with the cooler then we'll have to get back to troubleshooting.
How do you have the temp probe plumbed?
I hope some day soon we see you post you have opened your own shop.