3.9L Engine (VIN A)

Disconnect negative battery cable. Remove both valve cover assemblies. See appropriate article in ENGINES. Remove spark plugs. Engine will have to be rotated with crankshaft pulley bolt to bring each valve to base circle.

Measure and record each valve clearance using a feeler gauge. See Figure. Ensure clearance is within specification. See VALVE CLEARANCE SPECIFICATION (3.9L - VIN A) table. If clearance is not within specification, go to next step.

VALVE CLEARANCE SPECIFICATION (3.9L - VIN A) ⁽¹⁾

Application

In. (mm)

Intake

.0071-.0086 (0.180-0.220)

Exhaust

.0091-.0106 (0.230-0.270)

⁽¹⁾	Clearance is checked with engine cold.

NOTE: Shim thickness is stamped on back of shim in hundredths of a millimeter. A shim measuring 2.22 mm is marked "222" on shim.

Remove camshafts to access shims and tappets. See 3.9L V8 - VIN A article in ENGINES. Use the following formula to select proper shim thickness: Required shim thickness = measured clearance + base shim thickness - most desirable clearance. A mid range clearance is most desirable. Select proper shim, and mark for location during installation. Selective shims are available in sizes .086-.115" (2.180-2.915 mm) in increments of .0006" (.015 mm).
Install correct selective shim. Install camshafts and measure new valve clearances. Rotate crankshaft clockwise and repeat procedure for all valves as necessary. If any clearances are incorrect, repeat step 3. To complete installation, reverse removal procedure. See 3.9L V8 - VIN A article in ENGINES.