Differential Ring and Pinions & Kits

A ring in pinion is a gear set that converts power from the engine and transmission to the wheels. It is connected to the driveshaft u-joint via a pinion (gear) yoke and connects to the axles via the differential, which is bolted to the ring gear. Depending on the number of teeth on both the ring gear and pinion gear, the vehicle will either accelerate quickly with a lower top speed or accelerate more slowly but with a higher top speed. It is important to find the right combination that best suits your vehicle's intended purpose.

When changing ring and pinion gears, the first step is to remove all of the components from the rear axle being worked on. During dismantling, check other parts like the differential carrier, axles, and other components to plan for a purchase that will include everything you need. To remove the ring and pinion (depending on the rear axle type), the rear cover or third member is unbolted and removed. The brakes must also be detached so that the axles can be pulled from the housing. The axles are held in place with retaining clips, requiring removal of the differential cross pin to release them, or are bolted to the ends of the axle housing. Once the axles are removed, the differential carrier can be removed by unbolting the supports. Be sure to tag which side each support was removed from as well as the number of shims used on each side of the differential carrier. With the differential carrier and ring gear removed, the pinion gear can be taken out. This is done by removing the pinion nut from the gear. The pinion yoke is then pulled off the gear and it can be carefully pushed inward and removed from the housing. Note the number of pinion shims used for future reference. At this point, the differential housing should be free of any moving parts. A thorough cleaning is the next step. Remember to replace the outer axle bearings and seals at this time as well. Next, make a list of the parts you need for the swap. A differential install kit is strongly recommended to make installation easier with the correct parts including shims, gaskets, seals, all ring and pinion bearings, a ring gear bolt kit, marking compound, crush sleeve, and more. Swap kits are also available that include gear oil and the ring and pinion gears. Inspect any parts that may be reused and determine if you want to upgrade them or if they will be reinstalled. This includes the pinion yoke, differential carrier, axles, cross pin, retaining clips, etc. Clean and prep the reused parts for installation. Once the replacement parts are in hand and you have everything needed, begin the install in the reverse order of part removal. As each differential has different bearing preload, torque specifications, and other steps, be sure to research the correct installation instructions for your specific rear differential. When assembly of the ring and pinion install is complete, you can confirm you have the correct backlash with the marking compound procedure. Next, the rest of the parts can be installed and gear oil can be added. Finally, a test drive will confirm the rear end is working properly and no unusual noise is being heard.

Backlash (the side-to-side play between the ring gear and pinion) and pinion depth (the front-to-back play between the pinion and the ring gear) must be correct to prevent excessive heat and noise in your rear axle. In addition, pinion and bearing pre-load is just as important for proper operation. Begin with the same number of shims on each side of the differential carrier and pinion gear that were previously used. Otherwise, you will have to start with an estimated number of shims to get you close. The correct order to set up the ring and pinion gears is as follows: pinion depth, backlash, carrier bearing preload, and finally pinion bearing preload. If your differential has a solid spacer or pinion support instead of a crush sleeve, the pinon bearing preload can be set after pinion depth. When setting pinion depth, moving the pinion closer to the ring gear makes the pattern deeper, and shallower when the pinion is moved farther away. A pinion depth tool can help with this as well. When setting backlash, moving the ring gear closer to the pinion reduces backlash, while moving the ring gear father from the pinion gear increases backlash. Gear marking compound is used to help confirm that the teeth are making the correct contact patch and are not too shallow or deep. In addition, research all of the torque specifications to your specific rear axle for proper operation.

A JEGS expert is ready to answer your questions and help you find the differential ring and pinion gear set that you require for your specific application.