98 F-150 4x4...3in lift...Rear axle overheats when towing...trailer is a motorcycle trailer. Way below tow capacity. Rear brakes have been replaced...Anyone experience the same problem?

 

How do you know it's overheating? Smoking? Losing lube? Hot to the touch? When I was looking for the cause of a bearing roar, I thought my pinion bearing was going out because the diff felt hot. But, it was a wheel bearing and that was a while ago and the diff is doing fine. Just got back from a 6k mile trip.