GL-5 in gear box and transfer box

Forum: 

Hi all,

I have applied GL-5 valvoline (75-90) in my Sporty's gear and transfer box but I have noticed that the Daihatsu manual specifies valvolines of type GL-4. Will I have a problem? What is the difference between them? Thank you in advance...

GL 4

GL 5 is an updated or improved version of the old GL 4 specification oil, you can put a better oil into the box, but not a worse specification.

Oils and general vehicle technologies advance, this means that newer or additional specifications are laid down for vehicle lubricants, this means that newer specification lubricants will be far in excess of the old specs, and meet the new specifications. GL 5 has these new specifications applied to it, in simple terms it works at higher temperatures, maintains its structural integrity for longer due to improves synthetic additives, and operates for higher load cycles for longer; thus meeting the environmental considerations of oil disposal by requiring less frequent changes.

You will encounter no problems, it is a considerably better oil than the vehicle needs.

Yep, agreed.

Valvoline is a good quality American oil, so you should have no problems.

You could add some molybdenum disulphide based anti-friction compound too (2001G).

http://www.molyslip.co.uk/oil_supplements/

Other additives, based on low-friction PTFE, are available too. It's just that I think that Molyslip is the best thing since sliced bread.