JBugs Video Series

Clearancing Transmission Bellhousing:

Video Overview:

If you are swapping out an old 6-volt transmission for a 12-volt flywheel, you will need to make room for it by grinding down the transmission bell housing. This can be a very dangerous job. Please watch this video for proper procedures as well as safety precautions.

Video Tips:

Tools Used:

Air Powered Angle Grinder
Small Flat Head Screwdriver

Video Transcript:

The bell housing will be ground down so that we can fit a later model 12 volt flywheel.


The transmission case is made of magnesium and magnesium fires are nearly impossible to extinguish. Extreme caution must be used. Make sure that there's no steel in the area being ground as a spark could ignite the shavings.


Use a small, air powered angle grinder to remove material from the four engine bolt bosses so that we can mock up the new flywheel.


We use a flywheel mounted to a crankshaft along with a clutch disc and a pressure plate to show why the transmission must be ground. [We] use the assembly to indicate where the transmission needs to be ground down. The flywheel is installed into the transmission, onto the input shaft and spun a few times, then pulled out.


We can see where the flywheel is touching and grind the areas down. The process is repeated until the flywheel installs and spins without contacting the transmission.


Stay tuned and in the mean-time, head on over to JBugs.com for all your vintage Volkswagen transmission parts and accessories.