Black Gearbox OIl

[hughy69]

Hi have a NH 3.0ltr Gls Manual and had gearbox oil change by a freind some time ago about 10 months , i had the clutch replaced 4 months after the oil was changed and was told it was very black? after 4 months use???.. Have just changed it and put in Castrol VMX-M as i beleive penrite was put in previously.. Does that oil turn black or is it black to start with....? Gearbox was o/hauled some 4 years ago so wouldnt expect the internals to be knackered (i hope anyway)
Since castrol has gone back in it seems to change much better between gears what anybodies opinion on this condition of the black oil???

[6G74]

Its generally a honey type colour to begin with, when it discolours it normally turns grey / metalic like. Theres only a couple of possible causes, water ingestion, excessive time since it last got changed, or somethings nearly screwed, although after a rebuild this pretty common, but that was 4 years ago yeh?

[hughy69]

Its generally a honey type colour to begin with, when it discolours it normally turns grey / metalic like. Theres only a couple of possible causes, water ingestion, excessive time since it last got changed, or somethings nearly screwed, although after a rebuild this pretty common, but that was 4 years ago yeh?

I am really starting to think it was dirty oil put in by mistake it doesnt make sense for any other reason (maybe old engine oil in tranny oil can ???)I suppose it is lucky ive only done 9 ooo k on it and hope it hasnt done any damage may change oil again as a final flush in a weeks time...

[6G74]

Sounds good, ya havent done any water crossings or anytihng?

[hughy69]

Nah no water crossing as such just some shallow stuff on fraser island