Due to the fact that this is actually an interference engine design, if the belt has snapped, there will be considerable damage to the valves or pistons and this must be remedied through the removal of the cylinder heads. Camshaft locking tools, which normally come in a set with another tool known as the crankshaft locking tool, a belt spacer called a timing belt wedge and a camshaft timing sprocket gauge, Can be bought from spare parts dealers or other tooling suppliers' shops. The first step in dealing with the Chevrolet Venture is to first unplug the cable of the negative terminal and the next is to pulls of the timing belt cover. Intake the number one cylinder at TDC and rotate the crankshaft and set it at 60 degrees before TDC and remove the spark plug. Screw the crank shaft locking tool on the crank shaft would turn the crank shaft clockwise till it locks at approximately 60 degree and the locking tool lever arm butt against the water pump pulley flange. Position the special tools that clip the camshaft sprockets in the TOP position then loosen the timing belt tensioner unit and the upper timing belt housing to relieve belt tension and then remove the timing belt. In case the camshaft sprockets are tarnished or required oil seal replacement, they can be withdrawn at this same time. Clean the timing belt area and examine sprockets for the wear and damage on the mating surfaces, the timing belt itself for the cracks or the traces of the oil, and, finally, the tensioner should be checked for the smooth operation with the replacement of worn particles. If any of the camshaft sprockets were unbolted, bolt them on with those keys and tighten the bolts to the recommended torque again check for the positions of the timing marks. If you have to take off the crankshaft locking tool, then you need to put the camshaft locking tools if fitted before and correct the marks. Fit the timing belt onto the number one and two cylinder head camshaft sprockets in such a manner that the timing marks are aligned with the belt and then over the timing belt tensioner pulley, then under the upper timing belt/ idler pulley. Subsequently, place the timing belt over the number 3 and 4 camshaft sprockets on the front of the cylinder head, the paint marks of the timing belt must be in concordance of the sprocket marks. It is placed around the crankshaft sprocket such that the timing belt mark coincides with the sprocket mark and then secure it by placing the wedge into position to prevent any motion. To tighten the belt tension, turn the crankshaft in the anti-clockwise direction to ease the belt over the lower timing belt guide pulley, then take off the timing belt wedge and refit the crankshaft locking pin. Take out the camshaft sprocket locking tools and fit the timing belt gauge over the number 3 and 4 camshaft sprockets, such that its gauge mark matches those within the sprockets. If the marks are aligned, place the camshaft sprocket locking tool on the 3 and 4 camshaft sprockets, then rotate the number camshaft sprocket anti-clockwise in order to take out the timing belt play. The upper timing belt guide pulley need to be rotate in anti-clockwise manner so as to increase the tension of timing belt around the camshaft sprockets until the number 1 and 2 cam sprocket timing mark is aligned, if the mark is aligned install the camshaft sprocket locking tool on the 1 and 2 camshaft sprockets. Loosen the upper timing belt guide pulley bolt, bring the bolt to the required torque, then position the center alignment mark 1/8 inch above the mark on the spring loaded idler on the tensioner, remove crankshaft locking tool also the camshaft sprocket locking tool. Turn the engine 1-3/4 turns clockwise; install the locking tool for the crankshaft and turn it further until you find number 1 TDC aligned with the tool that locks against the water pump flange. Check the alignment of the camshaft sprocket marks, and arrow them if required, then bring the alignment mark of the tensioner center 1/8 of an inch above the mark on the spring loaded idler of the tensioner and finally quantify and tighten the tensioner bolt of the timing belt to its correct torque unit. All the same, double check the camshaft sprocket timing marks and the crankshaft sprocket marks, replace the timing belt cover and join the battery.
