Ford F8AZ-6256-BA Camshaft Sprocket

Remove the negative terminal of the battery and turn the engine to the interface of the piston travel in the number one cylinder. The crankshaft should be rotated 360 degrees and the number one piston should be several degrees before the TDC. Take of the right valve cover and install the dial indicator to the cylinder head so that the plunger part of the instrument touches the number one rocker arm. To do this turn the crankshaft in clockwise direction until the number one piston is on TDC for the second time then read the dial indicator on right side of the timing chain near the pulley and set it to zero. Then rotate the crankshaft anti-clockwise slowly until the pointer of the dial indicator rests on the upward movement, so identify the number of piston stroke it has traveled from the TDC point. In the event that the mark has shifted greater than 10 degrees, replace the timing chain and the sprockets. For timing chain inspection, once again, remove the negative battery cable and remove any parts that will limit the access to the timing chain cover but retain the hoses and wires. Remove the bolts from the accessory brackets and turn the number one piston to TDC on the compression stroke and do not turn the crankshaft until the chain and sprockets are replaced. Unbolt the vibration damper and unbolt the timing chain cover from the block and the oil pan being careful not to mar the cover. Turn the crankshaft in an anti-clockwise direction in order to tire the chain loosely on the left side then compare the degree of chain deflection from a fixed point on the block. If the deflection measurement is found to be more than One half inch then fitting of a new timing chain and sprockets should be done as a set. Check the condition of the camshaft gear; original ones are aluminum with a nylon surface; they tend to chip, and these small particles may cause restrictions in the oil pump pick-up screen. Also, it is recommended to examine the crankshaft gear for such problems. For timing chain and sprocket removal ensure that the number one piston is at TDC to temporarily avoid crank shaft movement, then remove timing chain cover. Set the timing marks of the crankshaft and the camshaft sprockets before you remove them, if necessary. Take off the three camshaft sprocket mounting bolts and unbolt the chain from both the sprockets. As an installation procedure, always clean the cover and the engine block surfaces so that there is no trace of the old gasket material. Even check the cover flange for some distortion and locate the keyway in the crankshaft sprocket engaging on the Woodruff key while fitting the crank, sprocket to the crankshaft without hammering the sprocket. Rotate the crankshaft until the key is at the top dead center, lay the chain over the camshaft pulley and rotate it until the timing indicator is down. Make sure that there is straight line drawn from the center of the camshaft, the camshaft timing mark, the crankshaft timing mark to the center of the crankshaft before applying Loctite on the camshaft sprocket bolt and tightening it. Replace the timing chain, apply oil to the oil seal contact surface of the Vibration damper hub and fit the damper in the correct orientation and in alignment with the Woodruff key. Replace the rest of the parts in the reverse manner mentioned, pour more coolant, check the oil level and start the engine to check more leakage.

It is very important not to rotate the crankshaft or camshafts after the timing chain(s) have been removed due to the possibility of harming the valves or pistons - special tools are required to lock the camshafts during removal. Start by using the number one cylinder with Top Dead Center and then pulling the spark plug and also taking out the negative cable from the battery. Next, the engine cooling fan should be removed as well as in certain models, the radiator should be taken off as well. Move on and remove the valve covers, drain the engine oil as well as take off the crankshaft pulley. Some models require also the removal of the water pump and its pulley, power steering pump, drivebelt tensioner, and idler pulleys. Remove camshaft and crankshaft position sensor connectors if necessary, and remove the air conditioning compressor without disconnecting refrigerant connections. Check all the connectors and brackets on the harnesses, and then undo the nuts and bolts that hold the timing cover and the cover away making sure that you do not use over torque. Take off the timing cover gasket and dowel pins, then timing chains between the crankshaft and the camshafts. For 1999 through 2004 two-valve engines, fit the camshaft and crankshaft retaining tools, to lock the camshafts at the TDC and protect them from being damaged. Take off the right and left timing chain tensioners and stationary guides, and if it is necessary - the camshaft sprockets. In 2005 and later three-valve models, the engine needs to be rotated to its proper position and the camshaft rocker arms should be removed in addition to making certain that the timing chain marks are easily seen before installing the timing chain guides and sprockets. For confirmation of its position, turn the crankshaft; next, remove dirt and grease on the joint surfaces; spread RTV sealant on the cover surfaces; grease the timing chains; bolt on the timing cover. Lastly replace the crankshaft front oil seal and continue with reversing the process put the right quantity of the engine oil and the coolant then start the engine to check for any possibilities of leaking.

One has to be very careful, as the crankshaft or camshafts cannot be turned with the timing chain(s) removed; this will result in damage to the valves or pistons. Special tools are required to immobilize the camshafts during this process. This is not a "freewheeling" type of engine, so if it has "jumped time," there will always be a need to strip the cylinder heads. The timing system is very elaborate, and it is easy for severe damage to occur on the engine. Only experts should operate on this, and all work should be rechecked before engaging the engine.Begin by disconnecting the negative battery terminal. Then, remove the rocker arms in two stages: first, preload the valve springs on cylinders selected for testing, then rotate the engine 360 degrees to remove the rocker arms from the remaining cylinders, making sure to label and store all parts. Next, remove the timing chain cover and the crankshaft position sensor toothed wheel, observing the word "rear" stamped for proper replacement.When replacing the timing belt, attach the correct camshaft holding tools to ensure the camshaft(s) remain at TDC, preventing interference with valve timing. Move on to the right and left side timing chain tensioners, chains, and stationary guides. Mark these for reassembly as needed. Check for abrasion, cracks, or other forms of damage, and replace any worn parts. Additionally, test the tensioner.To do a preliminary check on the crankshaft, turn the engine with the starter motor or by hand for at least two complete revolutions, feeling for resistance. Mount the stationary chain guides and crankshaft sprockets in their respective positions, and fit the timing chains to match the bright links, dimples, and timing marks.The timing chain tensioner and guide should be bolted with the tensioner locked in a retracted position, then the bolts tightened before the lock is removed. Finally, compare the location of all timing marks while rotating the crankshaft back to TDC, and complete the process by reversing the steps followed during removal.

Position the number one piston at TDC on the compression stroke.

Loosen the number one cylinder rocker arms and turn them out of the way. Then, attach a dial indicator to the cylinder head with the plunger in-line with and resting on the pushrod.

Do not allow the crankshaft to be turned from TDC while removing the camshaft sprocket bolt.