I found some time to work on the Tuff Torq K57R transplant project for my John Deere D130 mower, which had the L2 TLT200a transaxle (a K46 variant from around 2016/2017). I haven't bolted the K57R back on the mower yet but thought I'd throw out a couple tips for those who want to crack open their new K57R to "flip the wedge". I'll be referring to part #'s on this page:
TUFF TORQ K57R
As stated by others, if you want to keep the existing control setup you need to flip the wedge (part #36, "motor housing") to reverse the gear action (this transaxle was intended for some Husqvarna models with a different control scheme). In order to do the flip you must remove the pump & housing drive line that runs through the wedge.
The tricky parts are: (a) getting it back together, completely seated back into the housing so that the cover (part #3, lower case) will sit evenly all around the mating surface; and (b) not losing some small parts that will almost certainly fall out while you are handling the guts of this thing.
To address tricky part (b), here are some parts that tend to fall out during this operation: #25 pin, #35 washer, #28/#29/#30 IDS valve, spring and filter, #75 brake shoe, #54 jerky plate, #96 pin. Of special note is #25 pin, which is TINY and will definitely fall out when you tilt the pump housing after removal. I dropped out this pin several times, and fortunately found it each time (make sure you have a clean, uncluttered work space that will let you find anything dropped). If your IDS valve(s) fall out (and they likely will), make sure you recover the #30 filter, a TINY round metal screen that goes inside #28. I had lost this for a while and didn't even know it until I noticed one IDS valve sitting higher than the other. The screen was laying in the crankcase and luckily I saw it. No telling what would have happened if that little chunk of metal was floating around in there, and the IDS probably wouldn't have worked right either.
For tricky part (a), be patient and don't force anything. Test fit your #3 lower case after reinstalling all your parts. It is likely this cover doesn't sit evenly on the mating surfaces on your first try. After a few tries, I test fit the wedge/bearing/shaft combo WITHOUT the #24 pump housing so that it easily seated to its proper depth, then marked the wedge with a sharpie at its location. When you are reinstalling the entire assembly you must squeeze it or clamp it so that the cylinders compress. Ensure proper seating of the assembly to your marked depth and start the 3 inner bolts #27, but don't torque them until you are certain the #43 bearing is seated or at least clear of obstructions. Again, test fit the lower case several times during the process to ensure nothing will bind. There is very little clearance when you flip the wedge and you can break internal pieces of the soft aluminum case if you go full torque without ensuring proper fit. Again, ensure you don't let the #25 pin slide out by tilting the pump to much. Verify #25 pin is working after seating the pump by flicking the external bypass lever #13 and feeling it positively stop. Note that you must have this lever turned so that the flat surface of bypass shaft #12 will allow the #25 pin to be positioned correctly.
I'm letting the Permatex Ultra Black cure overnight and will be refilling with new 5W50 Mobil1 today. Also doing other stuff to the mower like the bushings-to-bearings upgrade for the front wheels, oil change, valve clearance set, new drive and deck belts, so it will be a while before a test drive. I do intend to try the test spin with a drill & socket suggested by rob87, after oil refill to get out any air pockets.
