Club 80-90 Forums

just read the posts again but this time thoroughly!!

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.

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

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.

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