[Brucelee]

Originally Posted by Frank M

Always use the OEM lube from Porsche.
It is formulated with all the correct additives to get maximum use of syncros.
If a lube is too slippery, as many are you will get an occasional grinding in second mostly however it can occur in other gears too.
When it grinds you are damaging the cogs on both the gear and syncro.
Eventually it will always grind and subsequently slip out under a load.

A GL4 is what to use and if you contact Mobil you will find they tell you not to use their GL5 product.

Replacing the lube under 100k is usually a waste of time and money anyway.

Based on what?