The transmission was indeed changed for 2015. There was a discussion about it already on this forum, but I can't for the life of me find it with the search function. I did find photos of the changes on another forum from a guy who rebuilds gl1800 transmissions.

2014 and earlier:
2014-1.jpg 2014-2.jpg

2015+:
2015-1.jpg 2015-2.jpg