AMC V-8 Timing Chain Replacement
Contributed By: Joe Schaefer
Note: From the 1973 AMC Jeep TSM J-73-1001 and for use as public information only.
TIMING CHAIN (V8’s)
Installation of the timing chain with the timing marks of the crankshaft and camshaft sprockets properly aligned ensures correct valve timing. A worn timing chain will adversely affect valve timing. If the chain deflects more than ½", it should be replaced.
CHECKING VALVE TIMING
- Remove the spark plugs and cylinder head covers and gasket.
- Rotate the crankshaft until No.6 piston is at TDC on the compression stroke. This places the NO.1 piston at TDC on the exhaust stroke (valve overlap position).
- Rotate the crankshaft counterclockwise 90 degrees (viewed from the front).
- Install a dial indicator on the No.1 intake valve rocker arm push rod end.
- Set dial indicator to zero. Crank the engine slowly in the direction of rotation (clockwise) until the dial indicator reads 0.020", at this point the milled timing mark on the vibration damper should be in line with the TDC or zero marking on the timing chain cover.
- If more than ½" variation in either direction exists, remove the timing chain cover and inspect timing chain installation.
- Remove the timing chain cover and gasket.
- Remove the crankshaft oil slinger.
- Remove the camshaft sprocket retaining bolt and washer, distributor drive gear and fuel pump eccentric.
- Rotate the crankshaft until the "0" timing mark on the crankshaft sprocket is closest to and in a centerline with the "0" on the camshaft sprocket as shown in Fig 24.
- Remove the crankshaft sprocket, camshaft sprocket and timing chain as an assembly.
- Assemble the timing chain, crankshaft sprocket and camshaft sprocket with the timing marks aligned as shown in Fig 24. Install the assembly to the crankshaft and camshaft.
- Install the fuel pump eccentric, distributor drive gear, washer and retaining bolt. Tighten the bolt to the specified torque.
IMPORTANT: The fuel pump eccentric must be installed with the stamped word "Rear" facing the camshaft sprocket.
- To insure correct installation of the timing chain, rotate the crankshaft until the timing mark on the camshaft sprocket is on a horizontal line at the 3 o’clock position. Beginning with the pin directly adjacent to the camshaft sprocket timing mark, count the number of pins downward to the timing mark on the crankshaft sprocket. There should be 20 pins between these two points. The crankshaft sprocket timing mark must be between the twentieth and twenty-first pin (Fig 25).
- Install the crankshaft oil slinger.
- Install the timing chain cover using a new gasket, tighten the retaining bolts to the specified torque.
- Go grab one of your favorite beverages, you’re done.