" Help - Need junk Sears lawn tractor"

Looks like you already have one!!

LOL, Sorry!! My apologies.

I must say I stopped buying any products from Sears that had a motor many
years ago. They don't stock/supply parts for very long. They want you to
buy a new one I guess. I've had to toss jig saws, and fit older drills with
new drill triggers (with custom jumpers). Sears was once an American Icon,
now well....much less.

MTD is a very large maker of many machines, Cub Cadet, Troy-Bilt, Yard-Man,
Ryobi, Yard Machines and White Outdoor. I would not be surprised if make
the Sear brand or perhaps they could tell you who makes that tranny.

http://www.mtdproducts.com/company/index.jsp

Best of luck,
Jim