Hopefully Restrorob will see this. One of my Toros (21" walkbehind commercial) transmission is not smooth when mowing. All of the zerks have been greased at normal intervals for the maintenace, rear wheels and gear box. Its kinda hard to describe, but the best way I can paint the picture is basically if you were in a car and going along, and then about every 2 seconds or so, hit the breaks, and then the gas, and the breaks, then the gas, and continue to do this infinitely til you got to your destination, then that pretty much describes what this jumpy effect of the transmission for my Toro is doing. Any thoughts as to why it is doing this, or what the problem could be. I bought it in May of this year.