Iv installed the locker on my 05 foreman and it works great, its real nice having both tires pullin. But when i got it it came with a little vile of oil that your suppost to add to the diff oil. My question is where do i purchase more of this, is it needed, what does it do, can i use the limited slip additive they sell at the auto parts for trucks in the diff. Im really not sure so any help would greatly be appriciated.