Never mix grease.....
Never mix grease.....
Never ever mix types of grease; Mixing lithium, high pressure / temp and regular (red grease and white / other color) together can or will cause a chemical reaction (crystals to form) and destroy the bearings. If you are not sure of what grease was originally used, get new bearings, clean the shaft and housing and start from fresh. Bearings and races are cheaper than a destroyed shaft and tow. On the other side, any grease rated for wheel bearing use is fine to use. Also remember to replace the seals and preferably use pressure bearing protectors (Buddy bearing, etc...) to keep the water out.
Hope this helped,
Nik