How to tell what type gearing I have?

FirstChevyForMe · Dec 9, 2003

I bought my Av used with many expensive mods done to the suspension, engine, and exhaust. How do I tell what type gearing is on this truck? On my other truck there is a label on the rearend, but I can't seem to find one on this one. With the amount and type of mods on this Av I would be surprised to see standard gearing for a Z71 is on this thing.

brheas · Dec 9, 2003

There is a label in the glove compartment the lists the codes for all options that were factory installed. Rear axle, 4.10 ratio (GT5) 3.73 ratio (GT4).

FirstChevyForMe · Dec 10, 2003

Got the GT4 :6:

02-Z66 · Dec 10, 2003

i was going to tell you the same. is this what you were hoping for? 3.73's.

kneptune · Dec 10, 2003

ok ill add another question to this one.

what if there is no sticker inside your glovebox? i searched my glovebox and have no sticker.

kneptune

02-Z66 · Dec 10, 2003

you can call GM, or dealer, and give them your VIN to find out how you vehicle is equipped.

FirstChevyForMe · Dec 10, 2003

i was going to tell you the same. is this what you were hoping for? 3.73's.

02-Z66, I was hoping or the 4.10. I will be towing a large trailer with about 6 sports bikes all over the country this coming spring and want the most effecient gearing to handle the load. Right now I'm right at the 7000lb max payload limit including passangers. 7000lbs is the max for a Z71 with 3.73 gearing right?

steelheadchaser · Dec 10, 2003

kneptune said:
what if there is no sticker inside your glovebox? i searched my glovebox and have no sticker.

You can determine your rear end gear ratio pretty easily.

Start by putting the vehicle in neutral with the parking brake off. Place wheel blocks on front tires. Lift the rear of the Av of the ground and support it with a pair of jackstands (never use only the jack to support the vehicle. Mark the driveshaft with chock in a position where it is easy to see and lines up with and index marker ( something close by on the undercarriage that doesn't rotate). Place a chalk mark on the rear tire at the 6:00 o'clock position (closest to the ground). By hand, slowly rotate the tire one full revolution while counting the number of full revolutions made by the driveshaft. If the driveshaft makes four full rotations, plus a little past your index marker, you have 4.10 rear gears. If it comes up a quarter turn shy of four revolutions you have 3.73 rear gears.