Randy Burleson

Birfield joints are normally fastened to the inner axle with a small circlip. This clip is a devil to install, and even harder to remove.

In 79-85 Toyota mini-trucks, 84-85 4-Runners, and 69-89 Land Cruisers, the well-known weakest link in the front drivetrain is the Birfield joint inside the enclosed knuckle. That's not to say that this joint is weak, because failure is rare in stock rigs, but low gears, big tires, and powerful engines can cause failure. Where other vehicles snap axles, Toyotas break Birfields, often when you have the wheels cranked to one side and are applying power.