A search revealed conflicting answers on this. I need to adjust my valves as they are noisy. Several posters have said that they do not require adjustment. Others have said that they are easy to adjust with the DOHCs. Does anyone have the service manual that can give me a definitive answer? I believe the backlash should be adjustable.
TIA

Your Xterra has hydraulic lifters and they are not adjustable. If they are noisey then either you are using the wrong oil, the wrong filter, or your lifters are bad. If you do a search for noisey lifters you should find lots of discussions about what is normal and what is not.