Genuine Mercury Grand Marquis Timing Chain

Mercury Grand Marquis Timing Chain Parts Questions & Experts Answers

• Chain - Timing
  F3LY-6268-A
  Q: How to inspect and replace a timing chain and sprockets on Mercury Grand Marquis?

  A: 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 ½ 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.