06 Gear (Axle) Ratios

[Slade8200]

Is there a way to tell what gear ratio a truck has based on its trim / body style? For example, do all crew cabs have 3.73, etc. Or were all the ratios just options that the customer chose?

 

What was most common for 06?

 

Tx.

[sahls01gmc]

The RPO code is listed in your glovebox.

[Slade8200]

I know about RPO codes.

[sahls01gmc]

To answer your question, no. You can tell what gears the truck has by the RPO codes....

[Slade8200]

And what were the options for that year? 3.23, 3.42, 3.73?

[Chris]

My friend has a crew cab with 3.23. Look at the option codes in the glove box. GU6 is 3.42, GU5 and GU4 dont bother with. GT4 is 3.73, and GT5 is 4.10

[Slade8200]

Like I said I know all about RPO codes I just wanted to know if you could deduce what gears the truck had just by looking at it.

[Chris]

You would have to peek at the codes. The only one that have good gears is the trucks marked Vortec Max. Even then you are looking at 3.73 or 4.10. There is no exterior way to tell without codes

[txab]