How often should you grease the zerks in a vehicle? I have a 1999 Silverado 2WD with some zerks in the front end (6) and some U-joint zerks. Is it based on mileage or time? The truck is not driven hard at all, has approximately 115,000 miles on it. Runs like new, it's very well looked after. While I'm at it, how long can I expect this vehicle (engine and transmission, specifically) to last?