Sodium based grease is not compatible with lithium based grease. Read the package labels and be careful not to mix the two types. If there is any doubt as to the type of grease used, completely clean the old grease from the bearing and hub before replacing.
Before handling the bearings, there are a few things that you should remember to do and not to do.DO the following:
Remove all outside dirt from the housing before exposing the bearing.
Do NOT do the following:
Treat a used bearing as gently as you would a new one.
Work with clean tools in clean surroundings.
Use clean, dry canvas gloves, or at least clean, dry hands.
Clean solvents and flushing fluids are a must.
Use clean paper when laying out the bearings to dry.
Protect disassembled bearings from rust and dirt. Cover them up.
Use clean rags to wipe bearings.
Keep the bearings in oil-proof paper when they are to be stored or are not in use.
Clean the inside of the housing before replacing the bearing.
Don't work in dirty surroundings.
Don't use dirty, chipped or damaged tools.
Try not to work on wooden work benches or use wooden mallets.
Don't handle bearings with dirty or moist hands.
Do not use gasoline for cleaning. Use a safe solvent.
Do not spin dry bearings with compressed air. They will be damaged.
Avoid using cotton waste or dirty cloths to wipe bearings.
Try not to scratch or nick bearing surfaces.
Do not allow the bearing to come in contact with dirt or rust at any time.
Only the rear wheel bearings require periodic maintenance. A premium high melting point grease meeting such as NLGI No. 2 or equivalent must be used. Long fiber type greases must not be used. This service is recommended any time the rear brake drum is removed.