boogieman

Is it possible to determine the rear end gear ratio with the last numbers of the Vin # 11552126 ? The is no tag on the rear indicating what it is...so i don't know if it is a 2 or 3 series carrier

GMautotech

Is that VIN supposed to be from your Vette (and the last 8 digits)? That VIN is no good in GM's system.

calemasters

If the correct VIN is 1G1YY24U055112126


the car was built with the RPO GU2 - REAR AXLE 2.73 RATIO

LS1LT1

Jerry if I recall, your car originally had 2.73s (now 3.73s) didn't it?
Are you just trying to determine if you still have the 2 series carrier (housing new gears) or is this for someone else's car?

aero400

Just realized - becaues the C6 has an enclosed torque tube, one cannot simply jack up the rear of the car, spin the rear tires and count the # of revolutions of the driveshaft. So that does make it hard to figure out what the ratio is without having a VIN or other codes.

IS there a way to figure out the ratio without a VIN or other coding?

LS1LT1

Even with the torque tube one should still be able to spin it in neutral with the wheels up I think.
And of course just checking the codes (GU2, G92 etc.) on the little sticker inside the vehicle determines a lot as well.

Michrider

You could do a mph/rpm calculator. See what the RPMS are at 70 in the direct drive gear. 3rd in autos 4th in sticks. And what the tire size is. There are some websites with RPM calculators that you could punch in the different ratios and tire size and it will give you RPMs for those gears.

aero400

Yes, you can spin the wheels, but you cannot see the rotating driveshaft to determine how many driveshaft revolutions per wheel revolution (or vise versa).

Good idea. But I've found that doing such measurements and calculations, for whatever reason, never yields super accurate results. It might be hard to determine with certainty between say a 3.23 and a 3.42. However, if one is merely trying to distinguish between a 2.73 and a 3.42, that method would do the trick of course. Good info - thanks.

LS1LT1

Oh true, I see what you were saying now.

boogieman

That is correct, I now have 3:73s. I purchased a spare C6 automatic transmission and the guy threw in the rear end. Usaully the rear has a tag, this one did not so I am trying to find out if its a 3 series carrier.

Thanks for the replies .......I guess its a 2 series which is really worthless to me. If anyone needs it let me know, make me an offer.

UDRIVESLOW

find your rpo code sticker.........