A few things.
1. I know here in 'merica we should all be able to tow every incline at 70 mph. However there are compelling reasons to consider keeping it a few mph slower.
2. as stated above, avoid OD. heat buildup in OD is pronounced and should be avoided. OD is not designed for that kind of sustained load. I've measured the heat temps in mine and it quickly goes up when OD is engaged until the cooling tstat catches it. Without OD, on level ground, 60mph, the trans never even reaches 135F where the tstat enables the cooler. That's real-world proof for me.
3. The drive axle is passively cooled and does not have the same thermal protection of the trans. By the time you need a fan-forced high-powered aux cooler, your back axle will be way overtemp. I highly suggest a synthetic lube for the axle.
4. axle gear weights - the shop which recently redid mine (bearing failure, towing....) was against going with a heavier lube. I've read, specific to OTR trucking, that the stock weights are best unless there is a design problem causing the mfr to go thicker. One argument is that the thinner lubes for some reason are better able to carry heat away from the gears to the case for cooling.
Good luck, be safe, and happy camping!
1. I know here in 'merica we should all be able to tow every incline at 70 mph. However there are compelling reasons to consider keeping it a few mph slower.
2. as stated above, avoid OD. heat buildup in OD is pronounced and should be avoided. OD is not designed for that kind of sustained load. I've measured the heat temps in mine and it quickly goes up when OD is engaged until the cooling tstat catches it. Without OD, on level ground, 60mph, the trans never even reaches 135F where the tstat enables the cooler. That's real-world proof for me.
3. The drive axle is passively cooled and does not have the same thermal protection of the trans. By the time you need a fan-forced high-powered aux cooler, your back axle will be way overtemp. I highly suggest a synthetic lube for the axle.
4. axle gear weights - the shop which recently redid mine (bearing failure, towing....) was against going with a heavier lube. I've read, specific to OTR trucking, that the stock weights are best unless there is a design problem causing the mfr to go thicker. One argument is that the thinner lubes for some reason are better able to carry heat away from the gears to the case for cooling.
Good luck, be safe, and happy camping!
