Sierra Marine 18-21001 MerCruiser Gimbal BearingNon-greasable MerCruiser gimbal bearing from Sierra Marine. Sierra engine parts are designed to meet or exceed OEM requirements.Fits: MC-1, R, MR, and Aplha (1974-97), Gen II Aplha (1991-97), Bravo I/II/III (1988-95)Replaces: MerCruiser Stern Drive; 30-879194A02; 30-60794A4; 30-60794B4; 30-60794A2; Includes: (1) Permalube gimbal bearing; (1) Grease passage plug; Installation Instructions for Sierra Gimbal Bearings: When changing the gimbal bearing to the permanently lubricated type, replace the grease fitting with the included grease passage plug.; Remove the grease fitting from the side of the transom housing.; Apply sealant to the threads of the grease passage plug.; Use a 1/8" allen wrench to install the grease passage plug until fully sealed.;