Holden diff / axle codes

[Phreddy]

Can anybody provide me with a comprehensive list - or at least point to the resources - of Holden's axle codes?? I'm talking about the code which appears on the identification plate - for a couple of examples, I know about these ones...

GU4 = 3.08:1
GM3 = 3.45:1

My SV6 has GT9 in the axle code field, I believe that's around 2.89:1 or thereabouts. I'm not looking at changing my diff - yet - but I would like the comprehensive figures to help out with some speedo calibrations.

So if anyone can point me in the right direction, I offer my eternal gratitude. This info must be out there somewhere....

Cheerz all!

[burnz]

GU80 = 2.96:1 from memory

[Phreddy]

Thanks Burnz - that's another one to the list.

Cheerz!

[peterj]

You can find quite a few here choose g-m for the rear axle codes.

RPO Codes.com- GM option codes,GM rpo codes,Regular Production Options,General Motors options

My clubbie is GW6 = 3.27

[Phreddy]

Outstanding Pete - thanks for that reference Mate, it's excellent! And not just for the diff codes either...

[burnz]

You can find quite a few here choose g-m for the rear axle codes.

RPO Codes.com- GM option codes,GM rpo codes,Regular Production Options,General Motors options

My clubbie is GW6 = 3.27

those code's are wrong or only relate to u.s.a.
they don't match holden codes at all

[Calaber]

Phreddy

I don't know if Holden still does it, but they used to stamp the ratio on the diff pinion shaft dust cover.