this is the most common transaxle used by mtd from the late 70's to the early 2000's fits way too many brands to list. this is the style that just has a forward and reverse and the gears or speeds are made up with the varidrive belt pulley. it is a good trans and is newer than the tractor it came off of. it looks like this was a replacement installed before the tractor fell into disuse. this is also the trans commonly used for racing lawnmowers.