We wondered when this would happen. Went to reel the power cord in on our 2017 3901MB and it wouldn't wind. The motor was running but wouldn't turn the reel. Can you get parts for these reels? We're thinking it's just the gears.

Is it a Morryde reel? If so I would bet repair parts are a phone call to the service DEPT , Brian is the service MGR at the factory in Elkhart Indiana . Give him a call if its Morryde they have great customer service.

It's not a Morryde, but thanks for the suggestion. I've included a picture from the Trekwood RV part site. It has no name.
I tore into the reel yesterday and will explain what I found and how I repaired it. I removed the sheet metal to expose the reel from the bottom (5 screws). Then pulled back the metal from the left side to access the gears. The housing cover needed to be removed (8 screws) to expose the gear box. While removing the housing cover, 3 pegs fell out(see picture of hand). Looking from the side behind the chain, I noticed where the pegs were inserted in the plastic disc. I then removed the sprocket and chain by unscrewing 2 screws. Noting the empty slots for the pegs, I inserted them three going one way and three the other alternating. This disc is plastic so I have no idea how long this fix will last. I replaced the chain and sprocket, housing cover and sheet metal. The reel then operated as normal.

Great job! That's the great part of making your own repairs, the satisfaction of fixing it & now knowing what to look for if/when it quits again.

Well, the fix didn't hold. Went to retract my cord today and the pegs fell out of the slots. I guess I"ll get this addressed at the rally.