Glad to hear ya had a spare. Real interested to know what happened in the old trans - might be worth splitting it to find out, and to save the rest of the parts for when ya don't have a spare on hand and something else blows up.
Well, I got time to do my "Alien Autopsy" and see what I could find.
I was expecting catastrophic destruction towards the input end of things. When I got it apart, I could find nothing wrong. I went over it and over it.
Symptoms: unit would "groan" occasionally when it was still working.
Never had it under any more load than pulling another tractor around once and mowing.
It slipped twice during use before movement ceased.
It just quit going forward. It would go backwards for 10 feet, then that stopped too.
When it went bad, the brakes stopped working.
Here is the unit upon opening. Not much wear and tear, pretty clean.
I looked all over, no visible breaks, no broken teeth.
Finally found it, I had to lock up both axels and turn the input to see where the slip was... And it was in the spider area, but nothing was broken.
All the gears were turning, but one shaft would slip.
Grrr. Lets hear it for quality control.
So, I put my meager welding skills to work and it works like a charm.