I took the steering knuckles off my wife’s '01 Corolla and had the bearings replaced. Whenever I’ve done roller bearings in the past, I’ve loaded the cages up with as much grease as possible. These ball bearings look like no extra grease was put in beyond what they maybe had in them from the factory. Not loaded up at all. Do these FWD ball bearings just run on less grease or should the mechanic have put extra grease in them? If they need more grease, I could take the coupling off my grease gun and shoot some down in there, but it would be hard to get it all the way back to the other set of bearings (I’m assuming that there are cages/balls at both ends of each bearing.)
These should be factory sealed bearings. Adding more grease to them is not possible and not necessary.
These bearings aren’t sealed; I can see the ball bearings (and a small amount of grease) in the end of the hub.
You should not be able to see the ball bearings. There should be a grease seal on the outside of the knuckle as the hub flange exits the knuckle assembly. There should be a grease seal on the inside of the knuckle followed by a dust deflector.
You don’t want to overload the bearings with grease as there is not space for excess to go. Oldschool wheel bearings had a lot of space between the inner and outer bearings for excess grease to displace.
I work with a lot of large electric motors and industrial machinery and I have seen more problems caused by over greasing than by insufficient greasing.
As long as the rollers have a film of oil on them, they are lubricated, they don’t need or even want to be swimming in grease.
Grease is oil that has been thickened by some sort of soap, usually lithium based soap. The purpose of the thickening agent is just to hold oil, it is the oil in the grease that does the lubricating.
Never mix polyurethane based grease (Exxon Polyrex) with lithium or any other type of grease, they are incompatible and will liquify and run out of the bearing housing.
I couldn’t see anything on the hub end, but could see the bearings on the inboard end, which did have the grease seal and the deflector installed. The other hub looked to have a little more grease, so I guess the mechanic did add some to both. I installed them without adding any. With 180K on this paper route car, I’m sure something else will fall off or blow up before the bearings ever wear out. 
Good point. I recall reading about the dangers of over-greasing electric motor and drive shaft bearings in the manuals for the equipment we have at work. That may apply to auto wheel bearings as well.
I will still assert these are sealed bearings.
Just to double check, I searched various automotive parts sites and every bearing listed was a sealed front bearings for a 2001 Toyota Corolla.
Here’s a link to the bearing from the NAPA site.
http://www.napaonline.com/Search/Results.aspx?Ntt=wheel%20bearing&Ntk=Keyword&N=599001+102001+50070+2070008
What is the value of adding more grease to them than the manufacturer has added?