Cadillac 12591689 Sprocket, Camshaft

To remove the timing chain cover, you need to first detach the negative cable from the battery and drain all the coolant. Afterwards, take out cooling fan, water pump, drive belt pulley and vibration damper. Then remove crankshaft position sensor and wiring harness nut. Remove oil pan then disconnect wiring harness clips from front cover. Remove crankshaft position sensor and camshaft position sensor with its jumper wiring harness. Afterward, remove the cover bolts and separate timing chain cover from block. Remove crankshaft position sensor reluctor ring and check timing chain free play. When needed replace the chain as well as sprockets. Be sure to align sprocket timing marks as well as release timing chain tensioner. To install timing chain cover clean engine block sealing surfaces then line up keyway on crankshaft sprocket. Press sprocket onto crankshaft while aligning balance shaft gears on opposite ends of shafts. Position crankshaft comparison camshaft sprocket in a way that allows passage of a looped chain over it. Apply thread locking compound onto camshaft sprocket bolt threads then tighten them up. Install crankshaft position sensor reluctor ring and apply RTV sealant to engine block sealing surface. Place new front cover and oil seal assembly in place plus tighten down on retaining bolts of cover afterward screws are tightened except for one at each end of upper edge of front plate where the attachment is made at an angle toward middle). Finally put back oil pan, vibration damper and then crankshaft position censor.

It is necessary to employ a special tool, camshaft holding tool, number GM# J-44221 or equivalent, for this operation. The timing system is a bit complicated and if a mistake is made during this process enormous damage to the engine can occur; therefore the work of this kind should be entrusted only to experienced personnel and it is mandatory to make sure twice of what has been done before starting the engine. Starting from TDC of cylinder number one the valve cover and the engine front cover should be unbolted; the word Delphi on the exhaust camshaft should be aligned with the valve cover mounting surface. Second, then, take off both the intake and the exhaust camshaft position sensors, then, the timing chain tensioner will then collapse thus requiring you to put a drill bit or a golf tee into position to keep it like that. Place the camshaft holding tool at the rear of the camshafts and then remove the top chain guide and the exhaust camshaft position actuator though holding the camshaft at the same time while undoing the bolt. Continue with the process of taking off the intake camshaft sprocket, disconnect the crankshaft sprocket from the camshaft chain, and then also take off the chain doing it while keeping the camshaft in a fixed position. Take out two access hole plugs from the front of the cylinder head, timing chain tensioner shoe bolt, timing chain guide bolt, after that take out the guide and shoe and the tensioner if they are being replaced. Take off the crankshaft sprocket, and prior to the startup of the engine, do the rotation of the crankshaft at least around two times and feel for any kind of load that signify an issue. When fitting the camshaft sprockets, fit new bolts and if disconnected, refit the tensioner and tighten to the indicated torque. Place the chain guide and shoe on the chain and tighten the bolts then fit the two holes with the access plugs. Before starting the engine, make sure that cylinder no.1 is again at TDC with the lobes of both Camshafts located at the front side of the Engine Head pointing upward with the Camshaft flats located at the back side also pointing upward. Fit the crank sprocket, still position the chain on the intake sprocket with one mark lined up with a dark link, thread the chain around the cylinder head through the crank sprocket ensuring the second mark is lined up. Bolt in the intake sprocket on the intake camshaft, and there might be a need to loosen and re-tightening of a holding tool for accurate alignment. Raise the timing chain up and manoeuvre the exhaust camshaft actuator over the correct sprocket so that a mark on the actuator is lined up with a dark link, then secure the actuator to the exhaust camshaft but do not over-tighten the bolt yet. Turn the exhaust camshaft actuator clockwise as far as it can be turned and make sure that the pointer is at the '0' mark before tightening the bolt. Loosen the intake camshaft sprocket bolt if it hasn't been done already and then use the drill bit or tee to turn the tensioner in and out Remove the camshaft holding tool. Lastly, align the timing mark and to finish the installation, reverse the whole procedure of removing number 4 cylinder head.

A few 1996 and all 1997 and later 4.3L V6 and 5.0L, 5.7L V8 engines have a non-reusable plastic front cover that has to be replaced because it is part of the oil pan gasket set and its re-use will lead to oil leaks while 1998 and later 7.4L V8 engines have a front cover and gasket which should Letting start by removing the negative battery terminal and then draining out the cooling system. Take off the upper and lower fan shrouds, drive belt, cooling fan and water pump or coolant manifold. Slightly turn crankshaft 360 degrees more so that No.1 piston is positioned at TDC of the compression stroke though do not turn the crankshaft until the timing chain and sprockets are replaced. The crankshaft pulley, the vibration damper, the crankshaft position sensor and the nut of the wiring harness fastened to the front cover must be disconnected. Take out the oil pan and cover bolts to unbolt the timing chain cover from the block, thus, maybe breaking the gasket seal. For 4.3L V6 and 5.0L, 5.7L V8 engines, the timing chain cover is of composite type and is non-reusable, it is suggested to renew the oil seal simultaneously. Take off the crankshaft position sensor reluctor ring and measure how much timing chain is loose like freeplay, If it reaches or goes past five and eight of an inch, then replace the chain and both sprockets. Remove the camshaft sprocket and chain assembly with the aerospace balance shaft drive gear still fitted to the camshaft. Scrub the contact and mating surfaces of the engine block and if the vehicle is being fitted with a new timing chain, align the key way of the crankshaft sprocket to the Woodruff keyway. N.B. Ensure that the sprocket is fitted to the crank and bolted firmly, do not hammer the sprocket since it may distort. For 4.3L V6 engines, set the balance shaft gears before the timing chain and the camshaft sprocket, that the timing indicators are correctly oriented. Put a non hardening thread locking compound on the sprocket bolt thread and the chain should be lubricated with some fresh engine oil. Crankshaft position sensor reluctor ring, with its dished side outwards, return the crankshaft and apply some RTV sealant on the sealing surface of the engine block and fit new front cover and oil seal assembly. Tighten to 20 Yamaki lb/ft the cover retaining bolts then bolt on the oil pan, vibration damper for crank shaft position sensor with new O-ring. For 2018 and later models, the items are vibration damper, vacuum pump, air conditioning compressor, oil pan, and oil pump. Turn the number one piston into Top Dead Center, pull out the electrical connectors connected to the Camshaft Position Sensor and the Actuator Magnet, and unscrew the cover bolts so as to detach the Timing Chain Cover from the Block. Check the position of the timing marks before unbolting the solenoid valve and the actuator. Check the timing chain tensioner and sprockets for any sign of wear and if the sprocket is worn or has to be replaced, the sprocket must be taken of the crankshaft discreetly. At installation, always purchase the timing chains with the sprockets and clean all of the sealing surfaces; then apply RTV sealant to the timing cover. The timing chain cover is then to be fitted loosely, the bolts are to be tightly fixed in a sequence and a new crankshaft oil seal is to be fitted. But to complete the installation the cooling system should be refilled and the engine oil topped up, the engine oil filter replaced and when the engine is running, check for signs of leakage.

To remove the timing chain cover, you need to first detach the negative cable from the battery and drain all the coolant. Afterwards, take out cooling fan, water pump, drive belt pulley and vibration damper. Then remove crankshaft position sensor and wiring harness nut. Remove oil pan then disconnect wiring harness clips from front cover. Remove crankshaft position sensor and camshaft position sensor with its jumper wiring harness. Afterward, remove the cover bolts and separate timing chain cover from block. Remove crankshaft position sensor reluctor ring and check timing chain free play. When needed replace the chain as well as sprockets. Be sure to align sprocket timing marks as well as release timing chain tensioner. To install timing chain cover clean engine block sealing surfaces then line up keyway on crankshaft sprocket. Press sprocket onto crankshaft while aligning balance shaft gears on opposite ends of shafts. Position crankshaft comparison camshaft sprocket in a way that allows passage of a looped chain over it. Apply thread locking compound onto camshaft sprocket bolt threads then tighten them up. Install crankshaft position sensor reluctor ring and apply RTV sealant to engine block sealing surface. Place new front cover and oil seal assembly in place plus tighten down on retaining bolts of cover afterward screws are tightened except for one at each end of upper edge of front plate where the attachment is made at an angle toward middle). Finally put back oil pan, vibration damper and then crankshaft position censor.

Tool required for this procedure is the special camshaft holding tool (part GM# J-44221 or equivalent). Start by rotating the crankshaft to set the engine to Top Dead Centre for cylinder number one, then unscrew the valve cover and the engine front cover. After collapsing the timing chain tensioner insert something like a drill bit or golf tee into the hole to keep the tensioner collapsed. The top chain guide can be removed by dismantling two bolts; next is the exhaust camshaft position actuator held by an Allen screw into a hex shape molded at the cam shaft while holding the camshaft still using a wrench. Then, take off the intake camshaft sprocket, relieve tension to the crankshaft sprocket and take off the chain while still holding the camshaft. Disconnect the two access hole plugs with a hex bit and the timing chain tensioner shoe bolt and the timing chain guide bolt, to pull out the guide and shoe and the tensioner, in case it is being replaced. The next step is to take out the crankshaft sprocket as is mentioned in the picture below. In case of his removal, the tensioner must be replaced and tightened to the optimum torque; the chain guide and the shoe must also be tightened with the bolts to the required torque. Screw in the two access plugs. Make sure cylinder one is still at Top Dead Centre, fit the camshaft holding tool making sure the lobes at the front of each camshaft are upright, the rear flats are upright. Insert crank sprocket and the chain must be fitted at angle on the intake sprocket on the marked dark link. Thread the chain over the cylinder head and over the crankshaft sprocket with the mark on the crankshaft sprocket lined up with a dark coloured link. Place the intake sprocket on the intake camshaft and it might become necessary to release a holding tool so as to slightly generate movement in the camshaft in other to align it before reengaging the holding tool. Raise the timing chain up and properly position the exhaust camshaft actuator over it; be sure that the mark on the absorber sprocket is over a dark coloured link before you install it to the exhaust camshaft permanently without heavily tightening the bolt. Once more, it can be just as necessary to wiggle the camshaft for proper positioning prior to reinstalling the holding tool. Turn the exhaust camshaft actuator clockwise until it cannot be turned further and set it in the position where the exhaust camshaft is fully advanced as failure to do this may cause severe problems to the engine. Retorque the intake camshaft sprocket bolt, respectively remove the drill bit or tee from the tensioner and withdrawal the camshaft holding tool. Last of all the timing mark should be aligned with the position where there are darkened links on the front of the intake camshaft sprocket, on the exhaust camshaft actuator and crank sprocket, then put all the parts back in as was done while removing them.

It is necessary to employ a special tool, camshaft holding tool, number GM# J-44221 or equivalent, for this operation. The timing system is a bit complicated and if a mistake is made during this process enormous damage to the engine can occur; therefore the work of this kind should be entrusted only to experienced personnel and it is mandatory to make sure twice of what has been done before starting the engine. Starting from TDC of cylinder number one the valve cover and the engine front cover should be unbolted; the word Delphi on the exhaust camshaft should be aligned with the valve cover mounting surface. Second, then, take off both the intake and the exhaust camshaft position sensors, then, the timing chain tensioner will then collapse thus requiring you to put a drill bit or a golf tee into position to keep it like that. Place the camshaft holding tool at the rear of the camshafts and then remove the top chain guide and the exhaust camshaft position actuator though holding the camshaft at the same time while undoing the bolt. Continue with the process of taking off the intake camshaft sprocket, disconnect the crankshaft sprocket from the camshaft chain, and then also take off the chain doing it while keeping the camshaft in a fixed position. Take out two access hole plugs from the front of the cylinder head, timing chain tensioner shoe bolt, timing chain guide bolt, after that take out the guide and shoe and the tensioner if they are being replaced. Take off the crankshaft sprocket, and prior to the startup of the engine, do the rotation of the crankshaft at least around two times and feel for any kind of load that signify an issue. When fitting the camshaft sprockets, fit new bolts and if disconnected, refit the tensioner and tighten to the indicated torque. Place the chain guide and shoe on the chain and tighten the bolts then fit the two holes with the access plugs. Before starting the engine, make sure that cylinder no.1 is again at TDC with the lobes of both Camshafts located at the front side of the Engine Head pointing upward with the Camshaft flats located at the back side also pointing upward. Fit the crank sprocket, still position the chain on the intake sprocket with one mark lined up with a dark link, thread the chain around the cylinder head through the crank sprocket ensuring the second mark is lined up. Bolt in the intake sprocket on the intake camshaft, and there might be a need to loosen and re-tightening of a holding tool for accurate alignment. Raise the timing chain up and manoeuvre the exhaust camshaft actuator over the correct sprocket so that a mark on the actuator is lined up with a dark link, then secure the actuator to the exhaust camshaft but do not over-tighten the bolt yet. Turn the exhaust camshaft actuator clockwise as far as it can be turned and make sure that the pointer is at the '0' mark before tightening the bolt. Loosen the intake camshaft sprocket bolt if it hasn't been done already and then use the drill bit or tee to turn the tensioner in and out Remove the camshaft holding tool. Lastly, align the timing mark and to finish the installation, reverse the whole procedure of removing number 4 cylinder head.

To remove the timing chain cover, you need to first detach the negative cable from the battery and drain all the coolant. Afterwards, take out cooling fan, water pump, drive belt pulley and vibration damper. Then remove crankshaft position sensor and wiring harness nut. Remove oil pan then disconnect wiring harness clips from front cover. Remove crankshaft position sensor and camshaft position sensor with its jumper wiring harness. Afterward, remove the cover bolts and separate timing chain cover from block. Remove crankshaft position sensor reluctor ring and check timing chain free play. When needed replace the chain as well as sprockets. Be sure to align sprocket timing marks as well as release timing chain tensioner. To install timing chain cover clean engine block sealing surfaces then line up keyway on crankshaft sprocket. Press sprocket onto crankshaft while aligning balance shaft gears on opposite ends of shafts. Position crankshaft comparison camshaft sprocket in a way that allows passage of a looped chain over it. Apply thread locking compound onto camshaft sprocket bolt threads then tighten them up. Install crankshaft position sensor reluctor ring and apply RTV sealant to engine block sealing surface. Place new front cover and oil seal assembly in place plus tighten down on retaining bolts of cover afterward screws are tightened except for one at each end of upper edge of front plate where the attachment is made at an angle toward middle). Finally put back oil pan, vibration damper and then crankshaft position censor.

To remove the timing chain cover, you need to first detach the negative cable from the battery and drain all the coolant. Afterwards, take out cooling fan, water pump, drive belt pulley and vibration damper. Then remove crankshaft position sensor and wiring harness nut. Remove oil pan then disconnect wiring harness clips from front cover. Remove crankshaft position sensor and camshaft position sensor with its jumper wiring harness. Afterward, remove the cover bolts and separate timing chain cover from block. Remove crankshaft position sensor reluctor ring and check timing chain free play. When needed replace the chain as well as sprockets. Be sure to align sprocket timing marks as well as release timing chain tensioner. To install timing chain cover clean engine block sealing surfaces then line up keyway on crankshaft sprocket. Press sprocket onto crankshaft while aligning balance shaft gears on opposite ends of shafts. Position crankshaft comparison camshaft sprocket in a way that allows passage of a looped chain over it. Apply thread locking compound onto camshaft sprocket bolt threads then tighten them up. Install crankshaft position sensor reluctor ring and apply RTV sealant to engine block sealing surface. Place new front cover and oil seal assembly in place plus tighten down on retaining bolts of cover afterward screws are tightened except for one at each end of upper edge of front plate where the attachment is made at an angle toward middle). Finally put back oil pan, vibration damper and then crankshaft position censor.

To remove the timing chain cover, you need to first detach the negative cable from the battery and drain all the coolant. Afterwards, take out cooling fan, water pump, drive belt pulley and vibration damper. Then remove crankshaft position sensor and wiring harness nut. Remove oil pan then disconnect wiring harness clips from front cover. Remove crankshaft position sensor and camshaft position sensor with its jumper wiring harness. Afterward, remove the cover bolts and separate timing chain cover from block. Remove crankshaft position sensor reluctor ring and check timing chain free play. When needed replace the chain as well as sprockets. Be sure to align sprocket timing marks as well as release timing chain tensioner. To install timing chain cover clean engine block sealing surfaces then line up keyway on crankshaft sprocket. Press sprocket onto crankshaft while aligning balance shaft gears on opposite ends of shafts. Position crankshaft comparison camshaft sprocket in a way that allows passage of a looped chain over it. Apply thread locking compound onto camshaft sprocket bolt threads then tighten them up. Install crankshaft position sensor reluctor ring and apply RTV sealant to engine block sealing surface. Place new front cover and oil seal assembly in place plus tighten down on retaining bolts of cover afterward screws are tightened except for one at each end of upper edge of front plate where the attachment is made at an angle toward middle). Finally put back oil pan, vibration damper and then crankshaft position censor.

Begin by removing the timing chain cover. For 2005 through mid-2007 models, rotate the crankshaft clockwise until the timing mark aligns with the oil pump housing mark in the 9 o'clock position, ensuring the flat segment on the rear of each camshaft on the right-side cylinder head is facing up.

Avoid rotating the crankshaft or camshafts separately with the timing belt removed to prevent valve damage.

After disconnecting the battery, the coolant should be drained.

Reset the tensioners and ensure they are maintained in the retracted position.

Next, remove the drivebelt and tensioner, followed by the engine oil pan and crankshaft balancer pulley.

To install the timing chain cover, you need to follow these steps:1. Clean the engine block sealing surfaces.2. Align the keyway in the crankshaft sprocket.3. Press the sprocket onto the crankshaft.4. Align the balance shaft gears.5. Position the crankshaft and loop the chain over the camshaft sprocket.6. Apply thread locking compound to the camshaft sprocket bolt threads and tighten them.7. Install the crankshaft position sensor reluctor ring.8. Apply RTV sealant to the engine block sealing surface.9. Position the new front cover and oil seal assembly.10. Tighten the cover retaining bolts.11. Install the oil pan.12. Install the vibration damper.13. Install the crankshaft position sensor.