Rear Differential Covers

What Does a Differential Cover Do?

A differential cover seals the back of your axle housing and keeps gear oil where it belongs. That oil bathes the ring and pinion gears, the differential carrier, and the bearings, so the cover's seal directly affects how long those parts last. When the cover leaks or gets dented, gear oil escapes and contaminants get in, which leads to overheating and premature wear. A solid cover keeps water, dirt, and road debris out while holding a consistent oil level. Some covers add fluid capacity or cooling fins to help the differential run cooler under load, towing, or hard driving. If you're rebuilding the internals behind the cover, browse matching differential carriers to complete the job. Choose a cover that fits your axle and matches how you drive. Whether it's a daily commuter, a tow rig, or a weekend track car, a dependable seal matters.

Differential Covers by Material: Aluminum, Steel and Chrome

The right material depends on your priorities: heat control, strength, budget, or looks. Each option JEGS carries handles those needs differently. Here's how the main differential cover materials compare:

• Cast aluminum: dissipates heat better than steel, which helps keep gear oil temperatures down during towing and spirited driving.
• Steel: delivers strength and value, and works well as an OE-style replacement for stock rear-end setups.
• Chrome: adds a bright show finish for builds where the rear axle is on display.
• Finned cast aluminum: uses cast-in fins to increase surface area for extra cooling under sustained load.

Finishes include black crinkle, natural, and chrome, so you can match the cover to the rest of your undercarriage. A cast-aluminum differential cover suits performance and towing builds, while a steel differential cover keeps a stock truck simple and affordable. If show-car looks matter most, a chrome differential cover finishes the axle cleanly.

Finding the Right Differential Cover for Your Axle

Start by identifying your rear-end type, because differential covers bolt on by axle model, not by vehicle year alone. JEGS stocks covers for GM 10-bolt, GM 12-bolt (8.875 in.), and GM 14-bolt truck (9.5 in.) axles, plus Ford 8.8 in. and Ford 10.25 in./10.5 in. 12-bolt truck rear ends. You'll also find Dana 44, Dana 60, Dana 70, and Dana 80 covers, Chrysler 8.25 in. and 8.75 in. options, and AMC Model 20 covers. Count the ring gear bolts, measure the ring gear diameter, or check the cover's shape to confirm the axle. The right cover protects the ring and pinion gears inside. A GM 12-bolt differential cover won't fit a Dana 60, and a Dana 60 cover won't clear a GM housing. If you run a Ford 9-inch, that axle uses a drop-out design, so shop Ford 9-inch third members instead of a bolt-on cover.

Differential Cover Gaskets, Hardware and Sealing

You can seal a differential cover two ways: with a reusable gasket or with RTV silicone sealant applied directly to the cover. A differential cover gasket gives you a clean, repeatable seal and faster installation, which helps if you service the axle often. RTV forms to the mating surface and works well on covers without a dedicated gasket, but it needs cure time before you refill the oil. JEGS carries gaskets from Fel-Pro, Mr. Gasket, Cometic Gaskets, and Mopar, plus chrome differential cover kits that bundle the cover with matching hardware. Torque the bolts evenly in a crossing pattern so the cover seats flat and doesn't leak. If you're already inside the axle, this is the right time to inspect the differential bearings and seals and set backlash with fresh differential shims. Clean both mating surfaces before assembly so the new seal holds.

Upgrade Covers for Cooling and Added Capacity

Upgrade covers do more than seal: they help your differential run cooler and simplify service. Finned cast-aluminum covers add surface area that sheds heat, which matters when you're towing, hauling, or running larger tires that load the gears. Many aftermarket covers also hold extra gear oil, and more fluid means more thermal mass to absorb heat and steadier lubrication under load. Built-in fill and drain ports let you change oil without pulling the whole cover, so routine service takes less time and makes less mess. A finned Dana 60 differential cover is a common upgrade on heavy-duty trucks and off-road rigs that see sustained strain. Some covers use a girdle-style design with support bolts to reduce housing flex on high-power builds. If your housing is worn or you're swapping to a heavier-duty setup, check rear axle housings too. Match the upgrade to your load, power level, and how hard you push the axle.