I was looking at the upper and lower ball joints and the rubber seals on my 560SL. The seals look intact without tears or apparent seapage. There are no grease fittings, so I think they are "permanently lubricated". Can the ball joints be lubricated? Do I use a special needle tip? Technique? Or should I assume they are really permanently lubricated? The car has 80K miles. Thanks for any advice.