How can I find out my car's gearing? [Archive]

Rich L

10-31-2006, 07:42 AM

its a 2002 Z-28 with auto trans.

Is it listed somewhere on the car?

2001NBMZ28

10-31-2006, 03:47 PM

Stock was either 2.73 (GU2) or 3.23 (GU5) on the Z28 A4 - check for the code on the driver's side door. Beware sometimes people change the gears, mine says GU2 but has 3.42's. If you suspect a possible change look at one of the calculators like www.f-body.org/gears/

Rich L

10-31-2006, 06:10 PM

Thanks for the info.

I found the GU5 code in the door... 3.25 gearing.

Can I assume that my car would be a little quicker in the 1/4 mile compared to the the same car with 2.73 gearing?? (assuming everthing else would be equal)

2001NBMZ28

10-31-2006, 06:27 PM

Probably, but too many other factors involved, never equal. GM called 3.23's their "performance axle option" for the A4 and came with an aluminum vs. steel driveshaft (2.73) cars. I've seen a lot of stock 2.73 cars do very well at the track.

Rich L

11-22-2006, 06:12 PM

Stock was either 2.73 (GU2) or 3.23 (GU5) on the Z28 A4 - check for the code on the driver's side door. Beware sometimes people change the gears, mine says GU2 but has 3.42's. If you suspect a possible change look at one of the calculators like www.f-body.org/gears/

Right now I have the stock 16" rims...

If I upgraded to 17's doesnt that really change the "true" gearing?