Can you elaborate on what issues you were having that made you do this and how you actually did it?

We paid as much for these, as a small car, so I expect them to last. After reading all the posts about the K46, I decided to check them. You will need two jack stands, a floor jack or someone to help, a 13mm socket and wrench, a long nose pliers, a drain pan, three qts of oil You only use a little over two qts. The top of the vent plug pulls off, and then you work the bottom half of the plug out. Turn the axel over and drain for two hours, refill, turning the pulley around 10 to 15 tumes every one half qt of oil. this helps to get the air bubbles out. This is for a John Deere LT 180. About an hour to pull the axel, two to drain and one to fill and one hour to reinstall. The first one took about two days, as I pulled the gas tank out to see what I was doing. (This is not worth the trouble). 6 bolts, two butterfly clips, and its out.

I have an LT 190. Does this have the same tranny? I was told mine had a sealed transmission and the dealer is trying to sell me a new tranny. My mower is having a very difficult time( non existant) in pulling up hills when the engine is warm

how about sucking the oil out from the vent hole location ? then refilling

***"how about sucking the oil out from the vent hole location ? then refilling"***
If there was a straight, unobstructed path for the suction hose to be inserted into the vent port that would allow it to reach the bottom of the trans case,.......that might be an option.
In reality, the case below the vent port is packed with internal components so any hose you might want to drop into the case will probably not even touch oil at all.
I also will guess that it has been tried without success because the problem of "draining and refilling" hydrostats has been approached many times.......by many different people. If suctioning the oil out through the vent port was a viable option..........it would have been published already by somebody who had "been there, done that".

So you drained and refilled it through the vent port?
Do you need to remove the bottom pan to do this? Pictures would be really cool.