Before we dive down the path of why and when to re-gear your Jeep, Truck or other 4x4 vehicle, let’s first go over the basics on what gears are and what they do. 


                                                                   What is a Ring & Pinion Gear Set?

Inside your front and rear differentials are a pair of lapped Ring and Pinion Gear Sets. The spline end of your pinion gears connects to your front and rear drive shafts and the gears on the pinion head mate with the ring gear which is bolted to the differential carrier, which ultimately spins your axles. The lapping process is when mated gears are rotated together under a light load with an abrasive media, this corrects any small errors in the gear tooth profile from heat treatment and ensures a good contact pattern. After the lapping process, ring and pinions are a matched set and cannot be used separately. Your Ring and Pinion gear ratio determines torque, top speed and fuel economy.

Factory gear ratios typically come in the 3.55-4.10 range. This ratio signifies how many times the driveshaft must spin in order for the wheels to turn once. For example, the driveshaft of a Jeep Rubicon with a factory 4.10 ratio ring and pinion would spin just over 4 times to turn your wheels one full rotation. Gears with numerically lower ratios are “taller” and numerically higher gear ratios are “shorter.” Taller gears provide higher top speed and fuel economy while shorter gears provide more torque and acceleration. Rock Crawlers prefer shorter gears in order to go much slower over terrain, providing the driver more control when navigating over obstacles.




 Why Do I need to Re-Gear?


If you’re reading this article you have most likely either already installed a lift kit and bigger tires on your vehicle or planning on it. When you install larger tires, the diameter of the tires, rolling resistance and weight of the new tires puts additional stress on your drivetrain. The factory gear ratio was not meant to accommodate this change and you may find it difficult to engage your final gear ratios and most likely a loss of fuel economy. Simply put, you’re losing power, performance, and money out of your pocket. 

Re-gearing can bring your vehicle either back to factory settings which can save you money on gas if your vehicle is a daily driver. Or if your Jeep or Truck’s primary purpose is to off-road, an updated gear ratio will provide the performance you need to tackle any terrain. 




How to Re-Gear your Vehicle


Re-gearing is a labor-intensive process and we strongly encourage you to research your local area shops and pick one with high reviews. See our Gear Ratio Chart (Gear Chartfor helpful instruction on how to pick your desired gear ratio. Keep in mind that many differentials have a carrier break, which can increase the cost of a gear job. Revolution Gear & Axle tackles this problem on popular gears by making a Thick Gear, eliminating the need for a new carrier.



Enjoy Your New Ride!


Now get out there and enjoy your decision to re-gear, bringing back your vehicle’s power and performance. But, remember to adhere to break-in procedures (Break In Procedureto ensure your new gears last you as long as you need them!