Push the vent hoses out of the way, I push them over behind the injector wiring and they stay put.
Next clean off the cover and the rubber seals on the bolts that hold the cover on. I do my best to keep as much dirt out of the engine as I can.
I wiped everything off and then blew the dust off of everything with compressed air.
This is what mine looked like before blowing the dirt off.
Once everything is clean, loosen up all 6 bolts until they will come out. I leave them in the holes to keep them clean and keep dirt from falling in the engine.The cover will slide right out toward the front of the truck.
This is what the underside looks like. Make sure that spring stays in the cover and take this time to inspect the gasket for cuts and make sure it is still in its groove. Don't ask me what that spring does.
Now we can actually adjust the valves. If both number 1 rocker arms are loose then we can begin. If they aren't, rotate the crankshaft 1 full revolution and position the mark back at the top. This should put the #1 cylinder at top dead center.
The short rocker arms are the intake valves and the longer arms are for the exhaust valves.
Insert the .006" feeler gauge between the rocker arm socket and crosshead. It should go in easily.
Be aware that the surface tension of the oil tends to stick the two together and can make it a little tricky to get in there. Then try to get the .015" feeler gauge in the same spot. Do not try to force it in there, if it slides in easily then the gap is too large.
If the .006" doesn't go in OR the .015" does go in, then adjustment is required. Lossen the 9/16" lock nut and use an allen wrench to adjust the gap to .010". Adjust the allen screw until the .010" feeler gaugejust drags as you push/pull it through the gap. Then hold the allen wrench steady and tighten the jamb nut to 18 ft lbs. If you have done this right, the .010" feeler gauge should have a little resistance as you drag it through the gap,but a .011" feeler gauge should not go in without forcing it.
The exhaust valves are checked/adjusted the same way, but have a minimun of .015" and max of .030". If adjustment is necessary, set them to .020" using the same procedures.
With the engine in this position, adjust the intake valves of cylinders 1, 2 & 4 and adjust the exhaust valves on #1, 3 & 5. *Remember #1 is closest to the radiator and #6 is closest to the firewall.