Next up on our air-cooled engine build, is installing the intermediate shaft and oil pump. We have already restored these parts and are only installing them in this episode. You can use a standard oil pump or a high volume oil pump. But remember, if you use the high volume oil pump, make sure the oil by-pass modification has been performed.
How to install the Intermediate Shaft and Oil Pump
Before installing the oil pump and intermediate shaft assemblies, install the bearings and seals. The bearings should be seated into the case making sure that the oil feed holes are aligned with the oil gallery holes in the case. The bearings should be firm in the case and have an equal amount protruding above the case bore to account for bearing crush. The oil pump to case seals should be installed into the case and should be installed dry without any sealants.

Connect the assembly
Connect the intermediate shaft and the oil pump using the splined sleeve. Making sure the c-clips are on both the oil pump and the intermediate shaft. The sleeve should move freely back and forth and should not require any force when being fitted. Install both timing chains onto the intermediate shaft drive gears.







Lubricate the intermediate shaft bearings using a suitable engine oil, ATF oil, or assembly lube. Pick up the intermediate shaft by grabbing the rear most timing chain and the oil pump. Lower the assembly into the case by guiding the forward most chain thru the lower crankcase. As the assembly is being lowered into the case adjust the length by lightly sliding the oil pump and intermediate gear so that the pump will go over the mounting studs and the intermediate shaft sits on its bearings.

Lock Tabs on the Oil Pump
Install new lock tabs onto the oil pump studs and install the 8 mm nuts. Work the 8mm nuts down to take up the seal pressure then lockdown one on the tabs. Torque the nuts to 25 NM all the time making sure the intermediate shaft will still turn freely. Fold up the lock tabs securing the nuts.
Ready to Close the case
Next up you will need to gather all the parts, tools, and sealant, in preparation to close the case. This should be a job you do refreshed, and uninterrupted. Make the time to get ready first, watch the video, and set your self up for success.
If you would like to start at the beginning, visit the mag case engine prep.
If you would like to go to the next lesson, visit Closing the Case