Mercury 1L5Z-6268-AA Timing Chain

Firstly, the left valve cover has to be taken off, and with that, loosen the number 5 cylinder exhaust valve rocker arm, turning it to the side. Fix a dial indicator on the end of the push rod in order to measure the vibration of the valve lifter. Loosen the crankshaft sprocket by a clock wise rotation providing the correct timing mark at piston number 1 at the Top Dead Center on degree indicator on the right side the chain will have slack. Scribe a zero line on the dial indicator stick and turn the crankshaft in the anticlockwise direction until the pointer shows the next increment on the dial indicator, observe how far the damper TDC timing mark has been from the pointer. If the reading is more than 6 then the timing chain and sprockets have to be replaced. Secondly, rotate the crankshaft in anticlock wise direction till the number one piston is at TDC, remove the negative terminal of the battery and lastly remove the timing chain cover. Locate the camshaft sprocket bolt and loosen it but make sure that the engine is off when you do this, you then remove the sprocket with the chain still on. Pop the crankshaft sprocket off some ways, and make sure that you do not lose the tiny crankshaft key, then have a look at the timing chain and sprockets if they are worn or have been damaged and replace them altogether. For installation ensure that the sprockets and the chain are fixed on the camshaft and the crankshaft in such a way that the timing marks are in line then use a brass drift and hammer to fix the crankshaft sprocket into place. The camshaft bolt and washer are to be installed and the bolts tightened to the specified torque, if the camshaft bolt has a drilled to oil passage it has to be open before installing the bolt and do not use any other type of bolt than specified. Last of all, lubricate the timing chain and the sprockets and replace the timing chain cover as well as the other parts that were disconnected.

To remove the timing cover for 2008 and earlier models, disconnect the negative battery cable, remove the drive belt and tensioner, disconnect the crankshaft position sensor electrical connector, and move the wiring harness away from the engine cover. Remove the crankshaft position sensor, crankshaft pulley, water pump pulley, and the electrical connector to the power steering pressure switch. Move the power steering pump aside after removing its bolt, then remove the bolts securing the engine cover. For 2009 and later models, raise the vehicle and support it on jackstands, disconnect the negative battery terminal, remove the drive belt and idler pulley, and then the crankshaft pulley. Support the engine with a floor jack, remove the front engine oil seal, water pump pulley, drive belt idler pulley and bracket, and the crankshaft position sensor. Loosen the front cover bolts evenly and tap the cover sideways if necessary before removal. For installation, clean the mating surfaces, install the engine cover within four minutes of applying a 2.5 mm bead of RTV sealant, tighten all bolts to specified torque settings, and ensure to re-time the engine using a new crankshaft position sensor with the necessary alignment tool. To remove the timing chain and tensioner, apply the parking brake, jack up the front of the vehicle, and support it on jackstands. Remove the timing cover, compress the timing chain tensioner, and place a pin to hold it in the compressed position. If the ratchet mechanism needs resetting, remove the tensioner, relieve the tension on the ratchet, and then reinstall the tensioner. Remove the tensioner mounting bolts, the loose timing chain guide, and the timing chain. If necessary, the left chain guide and camshaft sprockets can be removed. For installation, remove the camshaft alignment tool if installed, loosen the camshaft sprocket bolts without removing them, and install the left chain guide, timing chain, and right chain guide. Install the timing chain tensioner, tighten the fasteners, and remove the pin to engage the chain guide. Reinstall the camshaft alignment tool and tighten the camshaft sprocket bolts while holding the camshafts in place. Finally, install the timing cover.

Disconnect the electrical connector to the power steering pressure switch, which is located on a high-pressure hose within the power steering system.

The procedure can be made easier by supporting the engine with a floor jack from below or an engine support fixture from above, and loosening or removing the motor mounts to allow the engine to be lowered somewhat for better access.

If the reading on the timing indicator exceeds 6-degrees, replace the timing chain and sprockets.

Disconnect the CKP sensor electrical connector, then remove the sensor. Note: A new sensor must be installed anytime this sensor is removed, and it comes with a special sensor alignment tool.