just purchased a 01 2500 4x4 5-spd.anyone know how to determine my rear gear ratio.

 

Well, with a 3500 (shorter tires) and 6 speed (5th in a NV4500 and 6th in a NV5600 are very similar), if RPM's at 70 MPH are around 2000, you have 3.54 gears. If RPM's at 70 MPH are around 2350, you have 4.10 gears.

I also believe my truck's axle ratio is listed on a tag inside the glovebox door.

Rusty

 

Yes, the axle ratio is on the sticker inside the glovebox door. I found mine there. There should also be a metal tag on the rear diff itself with the ratio stamped on it.

 

Tire size will change your gear ratio also. its like for every inch above stock add .10 example: 4:10 stock tires 31" = 4:50 with 35" tires ....I just learnt that on TRUCKS TV today never thought I'd get to use it.

 

I don't know it's yoour truck not mine!!

 

I thought it was the other way around. When I look up tire calculators, they show that my effective gear ratio goes down (numerically) when I add taller tires. So the 35's get me 3.70 for my original 4.10's. Any one else know??

 

thanks for the help!checked my glove box and there it was. 454`s.i wont be pulling any supper heavy loads so these will do just fine.

 

oops! meant 354`s

 

That's the right way.

 

You can pull with the 3.54:1 ratio, I towed a boat and trailer como that weighed 17,500lbs, and I believe Haulin' in Dixie hauls a lot more and if I recal he has 3.54's.