Hi; I have a 2004 dodge 2500 diesel for a tow vehicle. It has about 103,500 miles on it. The lift pump has been replaced and I did replace the steering tie rods and other part in the steering. I have not done any work on the engine except replace the lift pump and maintenance recommended by owners booklet. The booklet states that the engine needs Adjustment of valve lash clearance at 116K. This is my first diesel truck so I am on the learning curve. Questions include: What is a adjustment of valve lash clearance? Is there other maintenance I should be doing? Seem to me that I have a lot of miles on the engine and have not had much problem. Comments welcome. 2007Jim