1978-81 Type 2 models have hydraulic lifters that require no adjustment.
Preference should be given to the valve clearance specified on the engine fan housing sticker, if they differ from those in the "Tune-Up Specifications" chart.
The engine must be as cool as possible before adjusting the valves.
If the spark plugs are removed, rotating the crankshaft from position to position will be much easier.
- Remove the distributor cap and turn the engine until the rotor points to the No. one spark plug wire post in the distributor cap. To bring the piston to exactly top dead center (TDC) on the compression stroke, align the crankshaft timing marks on TDC.
- Remove the rocker arm covers. At TDC, the pushrods should be down and there should be clearance between the rocker arms and valve stems of both valves of the subject cylinder.
- With the proper feeler gauge, check the clearance between the adjusting screw and the valve stem of both valves for the No. 1 cylinder (see cylinder numbering diagram). If the feeler gauge slides in snugly without being forced, the clearance is correct. It is better that the clearance is a little loose than a little tight, as a tight adjustment may result in burned exhaust valves. While a little looseness is somewhat desirable, too much looseness will cause the tappets to rap loudly as the engine reaches operating temperature. This is because the cylinder barrels and the heads on the engine expand or "grow" when hot, whereas the valve pushrods do not. This growing action increases the valve lash slightly.
- If the clearance is incorrect, the locknut must be loosened and the adjustment screw turned until the proper clearance is obtained. After tightening down the locknut, it is then advisable to recheck the clearance. It is possible to accidently alter the adjustment when tightening the locknut.
- The valves are adjusted in a 1-2-3-4 (exact opposite of firing [1-4-3-2] order) sequence. To adjust cylinders 2 through 4, the distributor rotor must be pointed at the appropriate distributor cap post 90ordm; apart from each other. In addition, the crankshaft must be rotated counterclockwise (opposite normal rotation) in 180ordm; degree increments to adjust valves 2, 3 and 4.
There should be a red paint mark on the crankshaft 180ordm; opposite of the TDC mark for adjusting valves 2 and 4.
Always use new valve cover gaskets.