Greases, Silicone Lubricants and Dispensing Gear

Grease, spray or paste: choosing by load, heat and materials

Grease is oil held in a thickener, graded by stiffness on the NLGI scale; No. 2 is the usual grade for wheel bearings and chassis joints. Extreme-pressure grease suits heavily loaded joints, and high-temperature types suit disc-brake wheel bearings. Different thickeners are not always compatible, so do not mix unknown greases. Silicone lubricant leaves rubber and many plastics unharmed where petroleum products swell them, but keep it away from anything you plan to paint.

Pumps, hoses and containers: matching drum size and pressure

Dispensing gear is sized to the container. A lever-action barrel pump is rated for drums of a stated gallon range, and its bung adapter must suit the drum. Hoses list a pressure rating in psi that should exceed what the pump or grease gun produces. Measuring containers with fixed spouts help with oil by the quart; keep one container per fluid so a trace of one product never ends up in another.

Questions about Greases, Silicone Lubricants and Dispensing Gear

Can I mix two different greases?

Avoid it. Some thickener types react with each other and the mixture can soften and run out of the joint. If you must change type, purge the old grease thoroughly first and check a compatibility chart.

What does NLGI 2 mean?

NLGI is a scale of grease stiffness. Grade 2 has a consistency close to peanut butter and is the common choice for wheel bearings and chassis fittings. Softer grades flow through central lubrication systems, and harder ones stay put.

Is silicone grease safe on rubber seals?

Silicone grease is widely used on weatherstripping and O-rings because it does not swell most rubber. Keep it away from any surface you will paint later, since silicone contamination causes paint defects.