Moog 620 Flush Type Grease Fitting Greaseable u-joint allows for new grease to flush out contamination and moisture reducing corrosion and wear. Patented thrust washer technology absorbs axial loads preventing metal to metal contact and ensures even grease distribution to the wear surfaces. Thrust washers are manufactured to tight tolerances to allow for easier driveshaft balancing. Includes an exclusive anti-drainback design to control lubrication flow and prevent dry start up. Needle bearings and snap rings are sourced from an original equipment supplier. Needle bearings provide size consistency and proper hardness for even load distribution. Snap rings are held to strict tolerances to ensure proper cup position and retention. Nitrile rubber grease seals use a compressed double lip design to ensure more effective protection from contaminants and are purgable for longer life. Seals utilize stringent multifaceted SAE performance standards to ensure consistently high quality.