BMW 335i xDrive Transfer Case Output Shaft Seal Replacement at your home or office.

What is the Transfer Case Output Shaft Seal all about?

Vehicles equipped with four wheel drive employ a gearcase to switch among two wheel drive, high gear four wheel drive, neutral mode, and low gear four wheel drive. This gearcase is known as a transfer case. It uses a chain drive and gear reductions inside in order to transfer power from the transmission to the rear differential and the front differential according to the driver’s input. The chain and gears rotate in fluid that lubricates and cools the components inside the transfer case, and seals keep the fluid from leaking out past the input shaft from the transmission and the front and rear output shaft to the differentials. When one or more of these seals leak, fluid not only gets on the undercarriage and ground, but the transfer case is no longer able to effectively cool and lubricate the internal components. If the internal components overheat and seize up, or a catastrophic failure occurs to the transfer case, the four wheel drive system will not operate.