I am looking to buy a 2004 2500HD and I need to know the rear axle gear ratio by looking at the VIN number, can this be done? I am wanting to know if it is a 3:73 or a 4:11. Thank you for any help you can provide.

 

I don't think it can be done by looking at the VIN number, but just look at the tachometer when cruising at 60mph. I believe that 2500rpms is 4:10 and 2000 is 3:73.

That's the easiest way I know of. Otherwise you could go through the codes in the glove box and look for a GT3, GT4, or GT5.

You could also jack up the truck and draw chalk lines on the drive shaft and tires and count the ratio of revolutions.

 

RPO Codes:

GK9
Rear Axle: 4.63 Ratio

GTY
Axle Wide Track

GT4
Rear Axle: 3.73 Ratio

GT5
Rear Axle: 4.10 Ratio

GU4
Rear Axle: 3.08 Ratio

GU6
Rear Axle: 3.42 Ratio

G80
Rear Axle: Positraction

HC4
Rear Axle: 4.56 Ratio

HC7
Rear Axle: 5.13 Ratio

 

I think the only ratio you could get was the 4.10 in a 2500 HD with a 6.0. Or I will re word my statement. The only ratio I have ever seen in this truck is the 4.10. In mine it turns about 2,400 rpm,s at 65 m.p.h. and it got 15 M>P>G> on a trip.

 

My uncles 03 Silverado had the 6liter and 3:73's. But he swapped them out for 4:10s.

 

Was it a 2x4 or a 4x4?

 

4x4.

I just did a little research and a 6.0 3.73 isn't all that uncommon. For 2010 the Silverado is sold with a 6.2 and 3.73's as well.

 

hi i recently raise my truck 3" on front and 4" on rear with the 2wd kit that i got from fabtech ,all of these i did was bcause i upgrade the tires/wheels for 20" and pirelli scorpion atr"s>275/55/20now i dont like at"all how i feel it on road, i would like to know if can i do an upgrade on the rear gear or i dont have to or what can i do now,even before when was still stock i feel it so slow and weick to ride but now its even worse, if anybody can give me an advise i thank you guys a lot in forward for your help...

 

Put some gears to compensate for the bigger wheels n tires. You added more weight to turn so it takes more power to do that. Adding gears will eliminate that.