Originally Posted by olly986

When you remove the caps, in the black part there is a small mark (moulding) drill this with a 1mm drill bit.

As for oil, it also depends on your driving style and track layout, there isn't a miracle setup works for all, and also do you use gear diff front and back or rear and spool ?

I found 50wt rear working well with cleaning putty fine on front until it got too hot and car became very tail happy, I am going back to spool next week to start and depending on result will fit the front diff with heavy oil (100000) or putty again 9depending on temperature).

To buy oils, any shop will sale some, depending where you live (you do not say where in Europe) Apex models in UK is reliable.