I had some vibrations when I pulled my trailer, 12' with a RZR 4 on it, bad at acceleration and went away when not pulling. Installed diff drop, same thing, then found the grease zerk on the slip yoke of the rear driveline was broke and it was dry. Greased it and the vibrations went away. Also had modify the sway bar links, sway bar was hitting the front driveline. Added 1 3/4" to the links. Seems good now. My front measurement is 22.25" center of cap to fender and rear is about 23.5".