Brand New Differential Bearing and Seal Kit. You will receive one differential kit to replace the front differential kit on the following: 2000 2001 Yamaha Big Bear 400 YFM400. These are for the internal defferential not outer axel bearings. We work in conjunction with manufacturers and distributors to acquire the best products at the best prices, which we pass on to you, our customers. All items are new and in usable condition, guaranteed to fit the models listed and the most affordable aftermarket parts you will find online. Customer Service Hours: Monday - Friday 9 am - 5 pm EST.