Volvo 240 - When should I replace the diff oil ?

Dont know if it has ever been done ? over 300,000 kms

Every 100000km

thanks, what product are people using ?? i have a 1989 240

Penrite GL5 full synthetic Pro-Gear 75w90
http://www.penriteoil.com.au/products.php?id_categ=4&id_products=376

AGREE

I use Nulon 80W90 mineral oil

Source: have never blown a diff up
Source: it's what the service manual says to use

Philia_Bear;93602 wrotePenrite GL5 full synthetic Pro-Gear 75w90
http://www.penriteoil.com.au/products.php?id_categ=4&id_products=376

I've just put this in the Dmax gearbox, rear diff and transfer case in an attempt to simplify things.

It is noticeably smoother.

And the M47 manual transmission ?

ATF Type F (or the Volvo-branded oil, which is apparently the best stuff)

jamesinc;93645 wroteATF Type F (or the Volvo-branded oil, which is apparently the best stuff)

M46 needs atf type f
The m47 works really well it and or some hpr20