re-greasing critical components

[XDevolution]

my car just hit 81,000 miles. i've kept up with the regular maintanance at the designated times. but, when is the proper time to re-grease critical parts such as ball joints, chassis, etc... and what is the best way to go about it? should i do it on my own or just take it to the dealer.

[CXTKRS1]

Ball joints, tie rod ends, and pretty much everything else are sealed and do not require any additional grease for the life of the part.

[XDevolution]

Really? There is no grease "nipple" that i can inject lubricant in. In that case thats awesome.