How to find rear end ratio (Over the phone)

[Homicide]

..... please excuse the near 8 year absence.



I'm in the market to upgrade my 99 4x4 with 70k miles to a Generation 3 Cummins, 2500, 4x4, shorty.



I'm trying to avoid buying a truck with a 4. 11 ratio. While discussing over the phone with a prospective sellor of my choice year of vehicle (2004-2007), how do I find out what the gear ratio is? Where do I ask them to look for this info on the truck?



Thanks in advance for help.

 

[n7gxz]

There is normally a metal tag held on by two of the cover bolts what have the ratio on it.



Kevin

 

[Wingate]

my 06 model does not have a tag bolted to the diff cover.

The axle ratio is on a printed tag... . its either on the underside of the hood, or its on the inside of the glovebox door.

 

[macdaddy]

My 05 has it on a sticker on the left side of the glove box.



If the sticker is gone youll have to do it the old fashion way. Lift the truck in the rear, mark a spot on the tire.



Now spin it one full revolution and count how many times the drive shaft spins. If it spins 4. 1 times shes got 4:10. 1's. 3. 73 times and its 3:73. 1's.



Mac

 

[Nyoest]

Or ask them how many rpm at 60'mph and compare it to a similar truck with known ratio. Older trucks the 4. 10 ran 2,000 at 60 and the 3. 55 were about 1600. Assuming stock tire sizes and similar trannies this could be the easy way to talk to a non tech savvy seller.

 

[HBarlow]

I believe a Dodge dealer can decipher the VIN in the Dodge dealership software.