5HP MTD Yard Machine Rototiller Model 410 Transmission Repair / broken transmission

I purchased this rototiller off of craigslist, not running. The seller told me "just needs new gas! Ran great before I parked it a few years ago!". Well, they lied. After I fixed the engine, I found that the tines would not engage. The rototiller would drive forwards, backwards, neutral, but would not engage the tines for tilling. This video shows what I found wrong inside the transmission, the part I used to repair it, and some additional comments if you want to dive in further.

IMPORTANT NOTE: You do NOT need to tear down the transmission as far as I do in this video to replace the shift fork! If you want to just replace the shift fork, it'll probably work great for you. You won't need to replace the grease if you just swap out the fork, and leave the old ball detent & spring. It's tricky putting all the parts back in the right place if you fully tear down the transmission. Beware!

I'm pretty sure the model number of my tiller is: 21A-410-000. (AKA: model 410). If you Google this, you'll find websites that have parts. I ordered my parts from Sears PartsDirect.
Shift fork part number: 618-0245B
Ball detent part number: 741-0862
Ball detent spring part number: (had to order from somewhere else. Can't find part #)

PROBLEM IDENTIFICATION & REPAIR:
0:20 - Description of problem
1:18 - Source of problem (bent shift fork)
2:04 - Showing how bent fork cannot engage tine gear
3:06 - New Shift fork installed (a note on purchasing parts)

FURTHER TEAR DOWN OF TRANSMISSION:
3:36 - Showing all parts pulled out of transmission
4:13 - Details about the gear that gets engaged for tines (I flipped the gear over. Not sure if this was a good idea, but it worked for me! NOTE: The original gear MAY have had those rounded corners intentionally. I don't know if this was wear and tear or not. Your choice.)
5:19 - Showing where the ball detent and spring reside (If replacing)
5:41 - Details about how the ball detent & spring work

GREASE! IMPORTANT IF REPLACING GREASE:
6:19 - What kind of grease to use (Alternative to OEM grease)
7:26 - If reusing the old gasket for transmission case...

CONCLUSIONS:
7:56 - Running the rototiller immediately after repairs
8:25 - One year later: Final comments on performance