Many people ask how they can determine axle ratio on their rig or at a wrecking yard. If you have a Dana axle, it is easy. There is a verticle tag bolted to the diff cover



The top number is the Dana part number for the axle. The bottom row has two numbers. The left one reads 4 10, meaning it is a 4.10 ratio. The bottom right hand is the tooth count for the ring and pinion gears 41 - 10