The Basics
You may have an interest in learning about differential builds for a few reasons. Generally those who want to learn do so because:
They want to change gear ratio in their vehicle.
They want to rebuild a differential that is damaged.
They need to learn for their job.
So regardless of your reason, you need to first understand the basics of the hypoid gear-driven differential used in nearly every automotive vehicle in the world. You have a large round ring gear bolted to the differential carrier, and it meshes with the small pinion gear which is basically a shaft with teeth on one end. The most important part of a differential setup is the proper meshing of these 2 gears.
Differential Overview
Here you can see each part of the differential. Photo credit is from mendmotor.com, which you can access by clicking here. Each part is important in it’s own way but we’ll mostly be talking about the ring gear, pinion gear, and the differential carrier.
The Ring Gear Teeth
Here you can see the basic anatomy of a ring gear tooth. Get used to knowing what these names mean because anyone who will help you with a differential setup will likely refer to the parts when giving suggestions. The drive side is generally the side of the gear that has power applied to it when going forward, and the coast is the side that meshes with the pinion when you let off the throttle. This is opposite for reverse cut gears, which we will explain later.
A differential is held together by very few parts and fasteners if you think about it, so pulling one apart is quite simple with some basic mechanical tools. You first need to remove the differential cover/drain the oil, remove the axle shafts, and unbolt the 4 carrier bearing caps. Next you can remove the carrier itself which should slide straight out. There are some tricks to this but for now, it should pretty much come out with a good tug. Then the pinion is only held in by 1 large nut on the driveshaft side. With that off, you can drive the pinion out through the differential housing.
Again, this is a very basic overview and there are a lot of small details to take note of. Those details will come later in this series. For now, learn the parts of the differential, and understand the anatomy of the ring gear teeth.
