Burning smell while backing a trailer, did I damage my clutch?

I have a 05 Nissan Frontier Crew Cab 4x4 with 61xxx miles on it. A couple of days ago I was backing up a 4900# trailer in to my driveway and due to the tight space and slight incline I had to make a lot of small moves and rev the engine rather high to get the torque needed to move the trailer. When I was in the last few feet of moving the trailer I started to smell a burning smell, I am not sure if it was rubber as I had spun one of the tires on the gravel driveway or if it was the clutch. The smell quickly cleared away after I parked and I have not noticed the truck driving any differently. If the burning smell came from the clutch how much damage could I have done to it? Should I run out and change the fluid to prevent further problems? Thanks in advance.

Overworked clutches will start to burn, which is probably what happened. There is no need to change the fluid, because that’s not what burned. The lining on the clutch disc, between the engine and the transmission, is what you smelled.

Odds are it just overheated from all the slipping and will be fine. You may have shortened its life by a few miles, but probably nothing more. Since the clutch is OK now, I wouldn’t worry about it.