Transmission Fluids

[Prerderp Lurker Find all posts View Profile Close Prerderp]

Hi Gurus,

My 240,000km servicing is coming up, and as you'd expect, the old girl is still purring along like a dream.

On advice from a very knowledgeable bloke at Repco, I've been using slightly heavier oil (15W50) in the engine to better protect it through its mid-life. Still within the range that the book suggests, just up the heavier end.

Does the same theory apply to transmission oil? 240,000km servicing calls for all fluids to be replaced, so I'll need gearbox, transfer, and both diffs. As they'll all be a bit worn (I've done more than my share of towing and off-roading) should I be using a more viscous oil to take better care of them? Or do you usually just stick to the standard in the book, which says SAE75W90 for transfer and gearbox, SAE90 for diffs?

For reference, I'm driving a Petrol Manual 6-speed, just to be different

Cheers!

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

In a whole lot of cars over 40 odd years I have added the appropriate Nulon. It has always quietened down diffs and gearboxes and made for much smoother gear changes. In the engine I found that it quietened them down as well as raising idle speed by about 50-100 rpm.One of my former cars was at 360000 when I sold it and it was still as smooth as, used no oil and gave the same fuel consumption that it did at 30000km. Could be the go for a high km car.