Castrol smx-o equivalent

[fullthrottle]

Hi All

Been doing a little searching, but can't find the answer I want.

Does anyone know what an equivalent manual gearbox oil is instead of Castrol SMX-O? At $60 a litre.

The specs just state its:

SAE 75W-85
API GL4
Opel B 040 0063

Cheers

[Cameron]

http://www.supercheapauto.co.nz/online- ... escription

[fullthrottle]

http://www.supercheapauto.co.nz/online-store/products/Valvoline-Duragear-Manual-Transmission-Oil-75W-85-4-Litre.aspx?pid=30513&menuFrom=60202#Description

Would be great if it was as easy as that.
For some reason, this stuff was only sold by GM for their manual transmissions. It has specific properties and as such when you ask for some replacement oil other vendors say you need to refer to the manufacturer (GM).

It's not a 4x4, just an old Holden Astra, 1.4L twin cam, 5 speed manual.

Possibly the SAE and API values are the key, but haven't been able to find a match. Maybe a match is not really needed and an alternative will do.

http://en.wikipedia.org/wiki/Gear_oil

[Swamped]

Castrol lube guide says use syntrans in the astras. check the model is right but there is a note saying fully drain oem synthetic oil as the alternative is a mineral oil.

http://www.datateck.com.au/lube/CastrolRetailNzl/

[fullthrottle]

Castrol lube guide says use syntrans in the astras. check the model is right but there is a note saying fully drain oem synthetic oil as the alternative is a mineral oil.

http://www.datateck.com.au/lube/CastrolRetailNzl/

Cheers, that info has helped alot.