Lubricants are very specialized in the technology of current transmissions, transfer cases, and rear ends. The synchronizer rings used in late model transmissions are no longer made of brass or bronze as in the past. Modern synchro rings are now lined with clutch paper, carbon fiber, Kevlar, sintered metal, and other material. Each of these compounds require lubricants with a specific coefficient of friction to function correctly as designed. Incorrect lube fill will create notchy, dragging shifts, and damage to the speed gears inside the transmission. Clutch driven transfer cases and limited slip rear ends have the same requirements for specified oils to prevent clutch chatter and noise in these units. Rockland Standard Gear manufactures a premium line of full synthetic lubricants to insure proper operation of the drive line components to improve durability and increased longevity. All of our Tranzilla lubricants meet or exceed all OEM specifications, and are sold at very competitive prices. Buy by the case for even greater price savings.