I have a HRR2168VKA Sn:MZCG-8518237, I would like to know the difference between the two transmissions: 2001-VL0-P00 and 2001-VL0-S00. I still can't get traction after changing the transmission, except when I lift the rear wheels off the ground. I installed S00, but still no traction. Any help would be greatly appreciated.