I know the pillowballs come slightly lubricated, but is it necessary to apply some type of heavy duty grease when installing new ones?

 

IMO, yes. It's not for lubrication, but filling up the void behind the rubber seals/boots will help keep moisture and dirt out. I've heard some people suggest some type of marine grease. I'm not familiar with the stuff, but it makes sense.

 

"Marine grease" is commonly available and will not wash out with water. It's meant for the wheel bearings on things like boat trailers.

I agree it's not going to lube the pillowballs themselves unless you build some sort of special packer but it should do a good job of sealing the pillowball bearing surface from the elements.

 

Along these lines.... I keep an I.V. syringe in my tool box that I keep bearing grease in. Last winter when I had the car up on the lift, I used it to re-fill behind most of the dust boots. At that time the bushings were < 2 years old but each still took some grease. They were filled during install and I still don't know where it went. Another reason why the marine grease might be something to use for that.

 

I packed my pillowballs liberally when I changed them out for the same reasons as pointed out above. However, I used a general purpose lithium based chassis grease.

There are 3 types of grease bases in common use, of which lithium is the most common. Note that they are not all compatible and mixing them can produce, well, unintended consequences which can comprimise the lubricating qualities of the grease, resulting in early failures. (I would feel alot better about lubing them if I knew exactly what the factory put in them to begin with--but the best guess is a lithium based product.)

Moral of the story: check your bases, and keep them covered.