I've had to replace zerks on my FEL & grapple. I take a working zerk from the opposite side of the FEL or grapple and trot on down to my NAPA dealer. Makes things a whole lot easier. Surprisingly, as I remember, the FEL had some European(??) sized zerks and the grapple was SAE. I got the SAE zerks from NAPA and the European ones from the Kubota dealer.