Gearbox oil

[karmannkarmann]

just read the posts again but this time thoroughly!!

[karmannkarmann]

Got the gearbox oil changed today, also lubricated all the gear linkage, drives and changes like a Swiss watch and wish I had done it a few months a ago when bought it.

[California Dreamin]

The reasons for the slight vagueness is that originally these boxes would have been factory filled with a straight 80 weight gear oil that was meant to last the lifetime of the vehicle (in VW's mind that was 10 - 15 years)
Now here we are... 21 - 33 years on and oil technology has improved so our recommendations, as you would expect, have also changed.

Semi Synthetic 75W90 GL4/GL5 is your baby...(must say GL4 somewhere on the label) fill on the flat until it runs from the fill hole.

Martin

[matt brighton]

Although oil choice for g boxes and enginesa topic of much heated debate on every c car / motorbike forum I have seen I believe that gl5 is a no for vw boxes as same as land rover g boxes too - something to do with reaction to bronze bushes with the more modern additives.

[California Dreamin]

Indeed....because of the increased amount of 'antisheer hypoid' additives that can react badly with yellow metal syncromesh components at high temperatures.
This is why you need buy a product that passes both standards..typically the product says: suitable for gearboxes that require a GL4/GL5 specification.

Martin