Skylark L4-144 2.4L DOHC VIN T SFI (1997)
Timing Chain: Technical Service Bulletins
Timing Chain, Sprockets, and Tensioner Installation
Tools Required
J 39579 Camshaft Sprocket Wrench
J 36008-A Camshaft Sprocket Alignment Pins
Important:
Ensure that the camshaft sprocket alignment pins are in the cylinder block and the timing chain housing, prior to installing the timing chain housing.
The camshaft sprocket alignment pins ensure proper chain housing and front cover location for correct front oil-seal-to-crankshaft alignment.
1.
Install J 36008-A through holes in the camshaft sprockets and into holes in the timing chain housing. This will position the camshaft for correct
timing. See Figure 4.
2.
Use the following steps if the camshafts are out of position and must be rotated more than 1/8 turn to install the alignment dowel pins:
Notice:
Failure to follow this procedure could result in severe engine damage.
a.
The crankshaft must be rotated 90 clockwise off of TDC to give the valves adequate clearance to open.
b.
Once the camshafts are in position and the J 36008-A Camshaft Sprocket Alignment Pins are installed, rotate the crankshaft
counter-clockwise back to TDC.
Notice:
Do not rotate the crankshaft clockwise to TDC. Valve or piston damage could occur.
Important:
The timing chain and crankshaft sprocket must be put on in a specific direction for chain noise and wear considerations. The surfaces that were
marked during removal should be showing when the chain and crankshaft sprocket are installed.
3.
Install the timing chain over the exhaust camshaft sprocket around the coolant pump sprocket and around the crankshaft sprocket.
4.
Remove the J 36008-A Camshaft Sprocket Alignment Pin from the intake camshaft. Use J 39579 in order to rotate the intake camshaft sprocket
counter-clockwise enough to allow the timing chain to slide over the intake camshaft sprocket.
5.
Release J 39579. The length of the chain between the two camshaft sprockets will tighten.
6.
If properly timed, the J 36008-A Camshaft Sprocket Alignment Pin will slide in easily. If the dowel pin does not fully index, the camshafts are not
timed correctly and the procedure must be repeated.
7.
Leave the alignment dowel pins installed.
8.
The keyway on the crankshaft and the mark on the cylinder block should be aligned, with the slack removed from the chain between the intake
camshaft sprocket and the crankshaft sprocket. If the mark and the keyway are not aligned, move the chain one tooth forward or rearward; remove
