All Balls Racing – Differential Rebuild Kits, including Differential Seal Only Kits for the 2015 Polaris Sportsman 325 ETX EFI front, 20-23 Scrambler 1000 XP front, 11-13 Sportsman 550 front, 16-23 Can-Am Outlander DPS 450 EFI rear, 14-23 Honda TRX420 FA solid axle rear, 07-11 Yamaha YFM350 Grizzly IRS front and 02-08 YFM660 Grizzly rear. A differential sits right where mud, sand and creek water live, and once an input or output seal hardens the housing takes on water, the gear oil turns to gray slurry and the ring and pinion pit. Replacing seals is a couple of hours; replacing a chewed-up diff is a weekend and real money. These kits include the input, output and cover seals plus the o-rings for one housing, in materials that stay pliable through cold starts and hot trail miles. Fresh seals mean quiet 4WD engagement, no oil misting onto the brakes and no driveline play. It is also the time to check ring gear backlash and refill with the right gear oil. Front and rear housings differ even on the same machine, so tell us your year, model and which end you are servicing and we will confirm the correct differential seal kit first.