Trying to figure out my gear ratio. For every turn of my tire, the drive shaft rotates 2.25 times. However, I've never heard of a 225 gear ratio.
Can anyone help me out.

 

Look at your RPO codes to find out for sure. What year truck do you have?

 

2002 1500 2wd. I looked at the RPO codes and it says GT4, meaning a 3.73 rear end. I guess I just don't understand how they get that.

 

What RPM's are you at on the highway at 70 mph steady?

 

About 2,000

 

well do you have an open or posi rear?

on mine i had to hold one tire steady and spin 1 tire 2 times and count the driveshaft revolutions and i got my 3.73

 

Well, if that is the case, then I probably have 4.50 (4.56?) gears. Doesn't matter, I'm going in and having them changed out to 3.73 today. I'm sick and tired of reading 85mph when I'm really doing about 72. And it should stop my ABS light from coming on.

 

Wow sounds like you've got a whole host of issues there.

 

Ok, took it in and had the gears replaced..............problem solved. Speed matches speedometer, and no more ABS light.
I wish someone would have told me earlier about simply rotating the tire and counting how many times the driveshaft turns. Since mine turned 2.25 per wheel revolutin, just multiply that by 2......equals 4.5 (or probably 4.56). NullHead, Thanks again for the assistance.