## Dana 30 Axle Information

08.01.2009 · Posted in Home and Garden Articles

Dana 30 gears make up the internal gear parts of a Dana 30 differential. They consist of a meshing ring and pinion gear and a secondary unit of side and spider gears.nnDespite there being many gears inside of an axle (six to be exact), when one refers to Dana 30 gears, they are referring to the ring and pinion gears and generally not side and spider gears.nnDana 30 gears are available in many ratios. The standard rotation models can range from 2.72 to 5.38 and from 2.73 to 4.56 on reverse rotation axles.nnWhat is the ratio? The ratio indicates the number of rotations the pinion gear must make to turn the ring gear exactly one rotation. This is calculated by taking the number of teeth on the ring gear and dividing by the number of teeth on the pinion gear.nnFor example, consider Dana 30 gear ratio of 3.73. Simply looking at this number (we don’t have to do any calculations), we already know that the pinion gear must rotate precisely 3.73 times to rotate the ring gear one time exactly. In a Dana 30 3.73 gear ratio, there will be 41 teeth on the ring gear and 11 teeth on the pinion gear. 41 divided by 11 equals 3.727 (41/11=3.727) but since gear ratios are measured in accuracies of hundredths (ie: two decimal places), we round this up to a 3.73 ratio. In “gear talk” you would say that you have a “Dana 30 with three-seven-three (or three-seventy-three) gears”.nnDana 30 ring and pinion gears come in a variety of ratios and knowing your vehicle’s needs will be very beneficial when choosing a gear set. It’s important to understand that numerically higher ratios mean your engine must run at higher RPMs to turn the wheels. The same logic can be applied to numerically lower ratios in that they let your engine run at lower RPMs to turn the wheels.nnWith this information you’ll now be able to choose a Dana 30 gear ratio best suited for your driving preferences whether it’s for fast, long-distance highway driving or ultra-slow, off-road rock climbing.