what is greases used for
White lithium grease can be used for lubricating household products, garage doors and automobile applications. It is also known as lithium soap. It is non-corrosive and temperature-tolerant, and it is said to outperform other types of lubricants.
White lithium grease has multiple applications. It is great for using on sliding doors and windows, to prevent them from squeaking. It can protect metal against rust and corrosion. It is made from a high-quality base oil. Other types of grease do not withstand heavy loads, but white lithium grease can. Automobile mechanics use white lithium grease because it can withstand very high temperatures, unlike others.
Like yours did. Your wheel bearings were probably originally lubed with a lithium-12-complex grease, a perfectly good grease for wheel-bearing use, even on a boat trailer if it's maintained. Shooting some more grease into the bearing cap with a grease gun isn't a bad idea. Shooting an incompatible grease in is. This counterpoints the need to completely remove the last vestiges of old grease from a bearing whenever it's repacked. Yes, you want to remove the dirt and wear particles, but odds are you won't know what kind of grease the last mechanic used. I'm not going to print a huge grease compatibility chart here, although that kind of information is available on the Internet.