1978-81 Type 2 models are equipped with hydraulic lifters. No valve lash adjustment is required.
REMOVAL & INSTALLATION
The lifters can be removed without removing the engine from the vehicle.
To remove the lifters, remove the rocker shafts with the rockers, withdraw the pushrods and pushrod tubes, then, using a magnetic probe, withdraw the lifters. Matchmark them with their respective cylinders to avoid confusion. Place the lifter with the body down to avoid oil leak-out, thus making bleeding unnecessary before reinstallation.
Installation is the reverse of removal. When the rocker shafts and rockers are installed, set the adjusting screws in the rockers so that the ball shaped part is flush with the surface. Turn the crankshaft until cylinder no. 1 is at TDC compression stroke. Turn the adjusting screws so they just touch the valve stems, then turn them two turns clockwise and tighten the locknut. Adjust the other cylinders in the same fashion.
Before installing make sure lifter is bled correctly by applying firm thumb pressure on the pushrod socket. A resistance should be felt.
Fill a can with engine oil. Remove the lifter lockring, pushrod socket, plunger, ball check valve with spring and plunger spring from the body. Be careful, the spring is very powerful! Place the lifter body in the can of oil so that it is completely submerged. Assemble the lifter except for the lockring and the pushrod socket. The lifter should be assembled while submerged in the oil. Open the valve with a suitable punch or scribe by pushing the punch down through the hole in the plunger to allow the oil to flow out of the lower part of the plunger. Insert the pushrod socket in the lifter. Cut an old Type 1 pushrod in half, then use it in conjunction with a press to slowly force down the pushrod socket until the lockring can be installed. The lifter must be submerged in oil the whole time.