The cavity that retains the thrust bearing is quite small, if it has not been lubed recently I would say if you have a lever type grease gun two strokes (about 3 grams of lube) and if a pistol grip type three pumps (again about 3 grams)...
If you over grease it, the bearing can run too warm causing an early failure, not to mention making a nasty mess, where as under greasing really is not all that detrimental, I grease mine literally to move the lube around and disperse any condensation/water in the bearing at the beginning and the end of the season.....
Hope this answers your question.
GT