Have d8l ser#53Y trans is over heating machine is sluggish, checked screens in torque scavenging pump both clean pulled cooler looks good nothing in tubes, when it gets hot tends to vear off to one side in reverse, gooing to check brake pressures and screen at rear bottom of trans , it came from Canada with cold weather stuff on is there a thermostat or cooler regulator that might be stuck?
You should start with a complete trans pressure test. I suspect you have a flow loss through the torque. Many of those machines had an extra oil pump added to provide extra flow through the converter. If the trans pump pressure is low the brakes can drag. Also check brake linkage is free, seized linkage will make brakes drag. Later Bob
I know this is an old thread but I was wondering if you had any luck? Only asking as I found a D9L and a D10N doing the same thing recently and it turned out being the brake linkage under the floor sticking. Not much fun under there after a while when the tranny has been a little hot!
I had a D7H that wouldn't cool. Found out with an infrared thermometer oil was cool going into torque/hot coming out and close to a 100° drop thru cooler.. After checking pressures, discovered that pressure at the outlet of t/c was low. Then studied the flow diagram in service manual and concluded the problem was the t/c pressure spool in the transmission control valve. This valve body is mounted inside the transmission housing. Pulled valve and completely disassembled on bench. Took me over five hrs but found a tiny piece of black crud about size of pinhead. No more trouble after that. Only reason I'm explaining so intently is I'm not sure I'd have ever figured it out without the infrared. Oil should be losing 30-50° thru cooler.
I had a d8l 53Y2499, had the same problem. put on a slope to see if it would roll in neutral to eliminate a dragging brake and it seemed to be fine. pulled the cooler out and cleaned it, still overheating, took the converter out rebuilt it, still overheating. Finally disconnected and cleaned and lubed all the brake and steering linkage and that took care of the problem It the dozer sat for more than a few months, I would pull up the floorboard, climb in there and spray everything that moved. never had a problem after that