Nice video on the transmission oil change. A couple of things I would note. If you are going to fill through the vent hose, there is no reason to remove or loosen the fill plug. The transmission will vent though the existing vent when draining. In addition, unless you want to know what the level was (and you could only tell if it was overfilled) there is no need to remove the level plug. The amount of build up on the drain plug magnet is interesting. I have changed the oil a number of times to try and minimize the amount of crap going through the gears and bearings in the transmission. Each time I have been getting a little less crude so it looks like it is settling down. I think the total amount I have removed looks like what I see on your drain plug on your 600 mile change.
The transmission is supposed to take one liter of oil and if fully drained, there is no need to use the level plug to check on refill as the first couple of changes ended up with a slight overfill so I haven't bothered to check it after that.
As to the crush washer fit around the drain plug, if you look at the plug itself you will see that it was designed to be used with and "O" ring seal instead of a crush washer. That is why it is undercut and radiused near the bolt head. However, the transmission is spot faced for use of a crush washer and not counterbored for an "O"ring so the only thing that will work is a crush washer. Bad design.
Bottom line is if anybody watches your video and have not changed their transmission oil the crap on the drain plug and the fine metal in the oil itself should motivate any owner to change the oil. You are going to get no parts or service from Victory (Polaris) on these machines so a little TLC is required to keep them running.
