My service manager says I am experiencing valve or lifter leak down. The result is a very loud ticking for about 20 seconds after the engine is started from cold. Will this eventually lead to bigger problems?
It very well might, since it's not really a normal thing regardless of what H-D may tell you. Once again, if something is truly "normal" and "acceptable", most should do it. Unless something has radically changed in the world of hydraulic lifters recently, most lifters don't leak down every time they are allowed to sit for a short period of time
and then take 20 seconds to pump back up. Do you hear that sort of thing in your other vehicles with hydraulic lifters or hydraulic lash adjusters? Didn't think so. A lifter is supposed to gradually leak down if pressure is applied via the pushrod, rocker, and valve spring, but most refill almost immediately when the engine is fired up again. If it really takes 20 seconds to "pump up", something isn't quite right.
Jerry