Chuckcobra 2 questions? Who's fluid are you using?
Synthetic fluid semi or full? Are you using a climbing fluid the slicks to the gears and bearings? If you are doing some hard driving for along period of time, the heat buildup is causing the problem. 2 ideals, make some small wide scoops under the car to push air onto the center of the carrier and cool it down. Go like nascar and build acooler and pump under the car to cool the rear. You could go electric or run it off the drive shaft yoke. I think thhis will solve your problems. If you get orange ducting like nascar uses, they make little 4" 12 volt fans that will force the air on the rearend and cool it. I think Don C with the periscope to the rear while being great engineering is a little over kill
Don system worked great for the rear brakes and rearend of his comp car. Good luck Rick Lake tells what happen after the repairs
