How Can You Tell What Gear Ratio You Have?

[Mazer18]

How do yall know what gears you're running? Is there a code in the glovebox or something like that? Or is it just being able to tell from the vehicle's performance?

[wlvrn1215]

RPO code in glovebox...or look at the window sticker if ya still have it

[2000DV4.8]

Look at the RPO sheet in the glovebox.

 

GU5 = 3.23

GU6 = 3.42

GT4 = 3.73

GT5 = 4.10

[pm26]

And if you do not find the code, jack up the rear wheels by the differential, and put the truck in neutral. Crawl under the truck, and count how many revolutions of the driveshaft it takes for the rear wheels to move one revolution. That number is your gear ratio.

[Mazer18]

Darn looks like I'm only carrying 3.42's. I saw a thread like this from a search where the guy was asked what his RPM's looked like at 70mph. He had between 1800-2000. He was told he definitely had 3.73's then. I have the exact same reading in my 4.8L 4x4. I just found my window sticker however and it does confirm 3.42's.

[2000DV4.8]

Darn looks like I'm only carrying 3.42's. I saw a thread like this from a search where the guy was asked what his RPM's looked like at 70mph. He had between 1800-2000. He was told he definitely had 3.73's then. I have the exact same reading in my 4.8L 4x4. I just found my window sticker however and it does confirm 3.42's.

 

He probably had a different tire size.

[Mazer18]

Yep, your right. I just found the thread and he had a 5.3L Z71 with 285's. I got a 4.8L 4x4 with 265's.

[2000DV4.8]

Yep, your right. I just found the thread and he had a 5.3L Z71 with 285's. I got a 4.8L 4x4 with 265's.

 

That'll do it. (the tire size, not the engine).