Yes, believe your right as 11.5 was what I had to go to. Still, large enough gear I think to be able to go the distance for wear when towing. Probably, big thing, is to do something most don't, and that is to change the gear oil at reasonable intervals. Changed mine after approx. 1000 miles and drove without towing for over 500 miles. Even on first tow, stopped every 10 or 15 miles, let it set with vehicle in neutral, park brake on, and let it cool and temper. That was what Yukon recommended and now have a very smooth and quiet gear. Probably will have my gear oil (rear diff) changed every 20 or 25 k. Depends on the drive/ tow conditions. Still say, oil/ fluids are the cheapest maintenance.