Spindle swap?
 

The other day while mowing I noticed the hex nut on my spindle was wobbling pretty bad so I dropped the deck and disassembled everything yesterday. I'm not sure exactly what happened or why I didn't notice it sooner, but the threads on the spindle assembly are nearly worn smooth and the woodruff key was missing. Any replacement spindle assembly I've found ranges anywhere in price from $60 to $225 but I found a guy on ******** selling 44C decks (35819x is the other number on the tag) for $50. Do you think I could swap out the spindles? It'd obviously be much cheaper and I'd have a few to throw on my parts shelf for the future. Please let me know what you guys think.

Which deck do you have and what tractor is it on?
An 'A' or a 'C'
Each uses a different belt
The 'A' uses a narrower belt than a 'C' which uses a wider belt.
I believe the spindle ass'ys are different as well between an A and a C

Sorry I was trying to upload some photos but I keep getting an error. My current deck is a 441u1111 on a 149

Here is the spindle threads

If the spindles are indeed interchangeable, you will have to swap your pullies onto them

As far as I can tell, the 44c spindle replaced number is 959-3226 (replaces 759-3226) and the number for my 441u1111 deck is 759-3479P (replaces IH-ST745). For the price it might be worth the 20 minute drive at least

I'd replace that 1/2 moon key and see if the pulley will tighten back up using a different nut
Is the keyway in the pulley in good shape? like the damage on the spindle is clear at the top end of the threads and the only way that key could have escaped is if the nut were backed way off to give it room enough to get the hell out of Dodge so to speak. Might want to clean up the threads on the spindle and give it a try.

Good luck!

The keyway at the top still looks like it would bite but it's nearly non-existent at the bottom. I hadn't really looked closely at the pully until now but looks like she's pretty warped, makes sense why the woodruff wasn't there. Not sure why any of that happened, it wasn't making any strange noises while running

If you can get the threads cleaned up enough to thread a new nut on, maybe all you will need is a different pulley then.
A pulley form a 44C will be too big.
You will have to source one from an A deck.
I have several.