Q: How to service and repair the valve guide seal, replace the valve stem oil seal, and valve spring on 2009 GMC Envoy?
A: Gather tools (J 38820, J 44222, J-44228-A, J 44226). Organize components, pressurize cylinder, secure crankshaft, raise vehicle, remove torque converter plug. Remove gear bolts, install guide, keep chain tight, shift sprockets, remove camshaft caps and shafts. Compress springs, remove keys and seals, inspect, lubricate, reinstall seals, springs, camshafts, sprockets, bolts, plugs, cover, plug, lower vehicle.