OEM 2004 GMC Envoy Timing Chain

2004 GMC Envoy Timing Chain Parts and Q&A

• Q: How to replace the timing chain and sprockets on 2004 GMC Envoy?

  A: To replace the Timing Chain and sprockets, you should first remove the camshaft cover, then remove camshaft position (CMP) sensor and the engine front cover. Rotate the Crankshaft clockwise until the #1 Piston is at top dead center (TDC) on the compression stroke, ensuring the word delphi on the exhaust camshaft position actuator is parallel with the cylinder head to cam cover mating surface. The camshaft holding tool (J 44221) should be installed to the back of the camshafts, take the tension off of the Timing Chain by moving the tension shoe down and place a tee in the tensioner holding the shoe stationary. Remove and discard the exhaust camshaft position actuator bolt, take away the exhaust camshaft position actuator and the other intake camshaft sprocket bolt and finally the intake camshaft sprocket. Next, extract the Timing Chain, as well as the sprocket from the Crankshaft, then wash and examine the Timing Chain and the sprockets. For installation, ensure the #1 Piston is at tdc, then install the Crankshaft sprocket onto the Crankshaft snout. Mention the dark link of the Timing Chain with the timing of the intake camshaft according to the sprocket, allowing the chain down through the cylinder head to and attach it to the Crankshaft sprocket, align the dark link according to the timing. Mount the intake camshaft sprocket on the intake camshaft and fasten it using new bolt tightened to 20 nm (15 ft. Lbs) and then fasten it additional 100 degrees by using the angle meter (J 450.59). Make sure the camshaft actuator is advanced fully before you put the exhaust camshaft actuator in position, ensuring that you align the dark link with the timing mark of the actuator sprocket. Mount the exhaust cam actuator to the exhaust cam and bolt it with a new bolt that is tightened to 25 nm (18 ft. Lbs.)and then rotate the bolt an additional 135 degrees using the angle meter (J 450.59). Deny the tee from the Timing Chain tensioner in order to have a tension, next remove the camshaft holding tool (J 44221) from the camshafts. Make sure to align the dark links on the Timing Chain to the marks on the sprockets, and finally, attach the engine front cover, the camshaft position (CMP) sensor, and the camshaft cover.