Well, my L43 just grenaded yarding logs and I am swaping in an L52 5 speed I had laying around... I really didn't mind the 4 speed up untill then and I've hacked on alot of 5 speeds that way without any problems so I guess they are weaker like everybody says. If you have a 4 speed just run it untill it takes a crap and put in a 5 speed.