GM 91172368
Belt Tensioner

The whole sequence to service and repair the Timing Belt tensioner starts with the removal of the Crankshaft Pulley along with its retaining clips and engine wiring harness from the Timing Belt cover and then the coolant pump pulley. Separate the eight bolts and one nut which attach the Timing Belt cover to the vehicle then remove it completely. Rotate the crankshaft by clockwise motion until the alignment appears between timing marks on camshaft gear (1,4) and Crankshaft Gear (2,3). Perform disassembly only when these marks align. You must never operate the camshaft or crankshaft separately when the Timing Belt is removed to avoid causing any harm. First loosen the tensioner bolt with the attached stud before removing the belt from both the crankshaft timing gear and the camshaft timing gear by pressing the tensioner plate upward. The work begins by removing the tensioner plate together with the tensioner then continuing with the removal of tensioner spring and spring damper. Check the Timing Belt for both cracks and signs of wear and do a replacement when necessary while verifying that the Timing Belt tensioner spins smoothly. Secure the tensioner plate to the Timing Belt tensioner before putting the tensioner plate lug into the Timing Belt tensioner hole. Attach the Timing Belt tensioner and tensioner plate to the cylinder block by using one bolt and one stud but do not fully tighten them. The timing plate must run in sync with the tensioner plate movement unless readjusting the tensioner plate lug. Install the Timing Belt by correctly positioning the camshaft timing gear v mark on the cylinder head cover and crankshaft timing gear punch mark on the oil pump case which should match with the arrow mark. Install the Timing Belt by lining up the arrow mark to the crankshaft rotation direction while the number one piston remains at top dead center compression position. The tensioner plate requires upward pressure while you begin installing the Timing Belt on both pulleys by keeping the drive side slack-free. Fit both the tensioner spring and spring damper onto the drive pulley before securing the tensioner stud with hand torque only. The Timing Belt needs to absorb one rotation with clockwise crankshaft motion followed by tightening the Timing Belt tensioner stud to 11 nm (97 inch lbs.) and the Timing Belt tensioner bolt to 27 nm (20 ft. Lbs.). A clockwise half rotation of the crankshaft should validate the positioning of marks number 1 and 2 on both the camshaft and crankshaft. Placing the seal correctly between the coolant pump and oil pump case requires the Timing Belt cover to receive eight bolts and one nut which need tightening to 11 nm (97 inch lbs.). Put on the coolant pump pulley while tightening four bolts to 24 nm (18 ft. Lbs.) and place back the Crankshaft Pulley.