[tharapita]

It's typical obfuscation by Volvo. I looked into that when I first got my car, and it turned out to be a Castrol ingredient designation, only to be found in Castrol MSDS data sheets with no corresponding oil products listed against it.

I've never followed it up, as I've never needed any gearbox oil, but the best I can suggest is to ask a Volvo dealer.

Having said that, Skandix indicate standard Volvo 75W GL4 manual transmission oil is correct for the M76 box.

Castrol's recommendation from their online oil selector is Castrol Transmax Manual FE 75W GL4 for both the M66 and M76 boxes.

Alright, thanks! Volvo's own recommendation got me confused as they have two different oil types listed for M66 and M76. I don't expect my Volvo dealer to be any more of a help than google.

 

[tharapita]

Neither will phone you back! The customer guides in Halfords says refer to dealer.
Give Opie oils a try online...

My local dealership must be one of the worst dealerships in developed world. More likely to get a call from Google.

Everything points to Transmax FE SAE-75W to be correct. It just seems weird to me that Volvo would create such confusion between the oil types. I'll attempt to cross-check that it will be right one before pouring it in, though.