The normal plug is 16mm. There are some 18mm steel inserts available which
can be used when you have a stripped thread. You retap the drain hole and
screw them in. The inserts have a small collar on them so they seat tight
and nearly flush with the crankcase.

I had one of these in my rebuilt engine and did not know it. One day, when
I changed the oil, I decided to use a new gasket on the drain plug. The VW
gasket for VANAGONs is a thin silver colored washer. The next time I
removed the oil drain, the sleeve unscrewed out and stripped the 18mm
threads. The thin VW gasket was not made to use with the insert and had
gotten compressed down into the collar of the insert. (I use a torque
wrench on everything, so this was not a case of overtightening). Since the
hole is already oversized, I not been able to find a good fix and have been
forced to use a rubber expansion plug ever since. Although it made me
nervous at first, the right plug installed carefully has proven to be
reliable and secure. The best plugs I found for the VANAGON are 5/8" ones
at Pep Boys. If anyone has a better solution, I'd like to hear it.

If you do use an 18mm sleeve, I would recommend using the old style, wide
copper gaskets instead of the little silver ones. The wider ones will seat
against the crankcase and not burrow down into the sleeve.

*****  John Clavin  |  jjc@bga.com  |  Austin, TX
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