I'll assume you are going to replace the entire set (sprockets, guides, etc.) which I got from O'Reilly for $79.
First, set engine to #1 TDC.
Remove valve cover, fan shroud, fan, drive belt, water pump, 4 10mm bolts from bottom front of head, and 3 10mm bolts from front of oil pan. Remove lower front shield to remove oil pump. remove oil pump/distributor drive shaft, noting the orientation of the drive shaft.
Remove harmonic balance using correct puller (can be rented from local auto parts store). Remove P/S pump and A/C compressor if necessary. Remove timing cover.
IMPORTANT: Before removing oil thrower and distributor drive gear, note direction of oil thrower.
Remove oil thrower and distributor drive gear.
Remove chain guides, tensioner, chain, and finally both sprockets.
The new crank sprocket can only be installed one way, by aligning groove with keyway. The new cam sprocket will have 3 guide holes on the mounting flange, and you will need to align the knock pin with hole #2. Both sprockets should have a small dot (timing mark) on the right side of the sprocket when viewed from the front.
To install new chain, inspect chain to find the two brightly colored gold links. These two links must align with the timing marks on the sprockets. Assemble and install chain tensioner.
!!! IMPORTANT: Be sure to use new gasket when installing tensioner. Tensioner is oil pressure fed and a leaking gasket could allow chain slack, leading to premature wear or break.
Install chain guides, being sure not to let tensioner pop out.
!!! IMPORTANT: The tensioner must be fully compressed. To accomplish this, loosen the 8mm bolts in the passenger side guide (the shorter one). Compress the tensioner, adjust guide to remove slack, and tighten the two 8mm bolts.
Double check that everything is still lined up properly, and make corrections as necessary.
Install distributor drive gear and oil thrower.
!!! IMPORTANT: Ensure oil thrower is installed facing away from the distributor gear. If not, it could get caught in the distributor gear and destroy the two gears or cause engine lockup.
Before installing timing cover, inspect coolant and oil passages. If there is excessive buildup, a good system cleaner is recommended. Replace timing cover gaskets to prevent oil leakage. The best way to reinstall the timing cover is to remove the oil pan, install the timing cover, and reinstall the oil pan (replacing the pan gasket). If you don't want to do that, simply grease the top and bottom of the timing cover and lightly tap it into place with a rubber mallet. This is to prevent damage to the oil pan and head gaskets.
To install the distributor drive shaft, dab some grease on the top side of the gear to hold it in place, and line it up with the distributor. If you are having trouble lining up the shaft, pull it out and look at it from the top, and you will see that the flange is offset. At #1 TDC, the offset will be towards the front.
Install oil pump, being sure to use new gasket.
!!! IMPORTANT: Failure to replace oil pump gasket could lead to inadequate oil pressure, which will cause severe engine damage.
The remainder of the installation is a reverse of removal, using new gaskets where necessary. Before installing your valve cover is a good time to check your rocker arm clearances. This is also a good time to replace your drivebelt, and any other maintenance items as necessary.
Sep 11, 2008 |
1986 Nissan King Cab