Genuine Chevrolet Astro Variable Timing Sprocket

Chevrolet Astro Variable Timing Sprocket Parts Questions & Experts Answers

• Sprocket, Camshaft
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  Q: How do you remove and reinstall Timing Cover,Timing Sprocket and timing chain in V6 engine on Chevrolet Astro?

  A: To take out the water pump first disconnect, then unbolt and then disconnect the crankshaft drivebelt pulley from the vibration damper, using a six-point socket and breaker bar for the tight vibration damper bolt. Place the number four piston at TDC on the compression stroke, do not rotate the crankshaft until the timing chain and its sprockets are replaced. Finally, unscrew the bolt on the crankshaft front and unbolt the vibration damper employing a puller that places as force on the damper hub in order to prevent damage. For the 1995 and models remove the crankshaft position sensor located on the timing chain cover and pull the harness off. Move on to take off the Oil Pan further to take off the timing chain cover from the engine block using a putty knife or a flat head screwdriver if rust have bonded it. 1995 and later models only, check the timing chain cover if removed, clean the detent confronting face of the camshaft sprocket and measure the timing chain free play, if more than 5/8 inch replace the chain and sprockets. For 1995 and later models, also take the Crankshaft Position Sensor reluctor ring and, for 2004 and later models, the timing chain tensioner. Untighten and eliminate the bolts fastening the timing chain sprocket to the camshaft, then, take off the camshaft sprocket and timing chain as a single unit while paying attention to the relative positions of the timing marks. When withdrawing the crankshaft sprocket you should use a two or three jaw type gear puller; be careful not to scratch the crankshaft threads. For installation, the housing as well as metal cover should be clean and free from any dist or deformation and gasket surface of the cover should be restored as required. Just ensure that the balancer shaft gears are adjusted before fitting the camshaft sprocket and tighten the crankshaft timing chain sprocket making sure that the key is in the right position. If it is, turn crankshafts so that its timing mark is on the first horizontal position, feed the timing chain over the camshaft sprocket and then install the camshaft sprocket such that its timing mark comes into contact with that of the crankshaft one. For 1995 and later models, install the Crankshaft Position Sensor reluctor with the dished side facing out, use thread locking compound on the camshaft sprocket fasteners and use poly-graphite withe timing chain. For metal timing chain covers, you should smear RTV sealant on both faces of the gasket and for composites apply new cover and crankshaft front oil seal and smear RTV sealant on the mating surface. Put on the timing chain cover and fasten the bolts, then, engage the oil pan and Crankshaft Position Sensor using a new gasket. Clean and apply oil to the crankshaft front oil seal and the sealing surfaces of the vibration damper; fit the damper and replace the bolt with the right one and tighten to the recommended torque. Last but not the least, perform the rest of the steps of installation in the order of the steps of removal at the reverse sequence.