Differential Cover Buyer's Guide
- A differential or diff cover is a panel, typically made from stamped steel, that houses the front or rear differential.
- The cover creates a tight seal around the differential, preventing any lubricant from leaking and ensuring the smooth operation of the ring-and-pinion gear.
- It is essential for off-road vehicles because it adds to the rigidity of the axle and differential, helping them stay aligned.
- A differential cover protects the ring-and-pinion gear from impact damage, while also protecting it from mud, water, and debris contamination.
- The cost of a differential cover will vary between vehicles of different years, makes, and models. OE replacement diff covers will generally cost you around $20 in the lower range, while a performance replacement in the higher range may cost you over $700.
- Replacing or upgrading your diff cover can help you protect your differential from impact damage, improve its cooling ability, and make its maintenance so much easier.
Have you ever looked at a slow-motion video of a vehicle completing a turn? If you pay close attention to its wheels, you may notice that they’re not all spinning at the same speed. The wheels outside the turn spin faster, while the wheels inside the turn are slower. A difference in wheel speed is needed because the inside wheels are covering a shorter distance while the outer wheels must travel farther. This is all possible thanks to the differential.
The differential is the final reduction point that transfers engine power from the transmission to the wheels. Most vehicles only have a rear differential, while some trucks and off-roading vehicles with 4WD systems will have both front and rear differentials. One part that is essential to the operation of the differential is the differential cover.
What is a differential cover?
A differential or diff cover is a panel, typically made from stamped steel, that houses the front or rear differential. The cover creates a tight seal around the differential, preventing any lubricant from leaking and ensuring the smooth operation of the ring-and-pinion gear. A durable diff cover is essential for off-road vehicles because it adds to the rigidity of the axle and differential, helping them stay aligned.
What is the purpose of a differential cover?
Most differentials will not wear out and will rarely need replacing on their own. Damage is usually a result of a frequently driving over rocks, branches, and boulders without a cover that’s specifically designed for off-roading. A differential cover protects the ring-and-pinion gear from impact damage, while also preventing the contamination of internal parts from mud, water, and debris.
The differential cover gasket creates a tight seal around the diff cover to prevent any gear oil from leaking. This fluid is essential in preventing accelerated wear on the gears, as well as dissipating heat to ensure their longevity.
How much is a replacement differential cover?
The cost of a differential cover will vary between vehicles of different years, makes, and models. To give you a ballpark figure, OE replacement diff covers will generally cost you around $20 in the lower range, while a performance replacement in the higher range may cost you over $700. Differential covers are sold individually or as part of a kit which comes with gear oil included.
Do diff covers make a difference?
If you are still contemplating whether or not it’s a good idea to replace or upgrade your diff cover, here are some of the advantages of getting a new differential cover that may help you make up your mind.
Increased durability and strength
Most stock differential covers are made from lightweight metal. Most of these covers provide sufficient protection for daily driving. However, if you drive with a high-horsepower engine or enjoy driving your vehicle off-road, you may need a rear differential cover that can withstand the impact from large debris and jagged terrains.
Performance diff covers are usually made from heavy-duty aluminum or steel. While they may be heavier than their stock counterparts, they make up for the added weight by being harder to scrape or dent.
They prevent gear oil from leaking and protect the differential from contamination from debris. Investing in a durable diff cover can save you a lot of time and money that you would otherwise spend on fixing a damaged differential.
Improved cooling ability
Proper lubrication levels must be maintained to ensure that the metal gears aren’t grinding against one another which could result in power loss and accelerated wear. Gear oil also plays an important role in heat dissipation from these parts.
Upgrading your diff cover can help you improve the ability of the lubricant to cool down the moving internal parts. The material used to make the diff cover can aid in the dissipation of heat from inside the differential. Aluminum diff covers are great for this purpose.
The design of the differential cover can also improve its cooling ability. Installing a larger diff cover will increase your vehicle’s differential fluid capacity. Increasing the fluid lowers its operating temperature, allowing it to cool down moving parts faster. Replacing a non-finned diff cover with one that features a finned design also allows heat to cover a larger surface area so it can be expended faster.
Replacing your differential cover can make future maintenance work on your differential so much easier. Some vehicle models feature diff covers that need to be removed before you can drain the oil. You may replace this with a diff cover that makes fluid changes less troublesome thanks to a drain plug on the bottom and a fill plug on top. There are also differential covers that are equipped with small glass windows that make oil inspections quick and easy.
Finding the right fit
Get the right parts shipped to your door in no time with CarParts.com. Shopping for industry-approved diff covers is so much easier with our built-in vehicle selector. Let’s say you’re looking for a Jeep differential cover—simply select the correct year, make, and model in our search filters to narrow down our catalog to all compatible parts.
Choosing a Differential Cover for your Car
The differential cover is component that covers and protects a crucial vehicle component called the differential. Basically, the differential is responsible for taking the power from the driveshaft before passing it to the rear axle. This allows the wheels to turn and the tires to not skid when you're driving. Because of this function, it's very important that a rusty and leaking differential cover has to be replaced immediately. There are many differential covers that are offered in the market today, but before buying, here are things that you need to consider.
Stock differential cover vs. Performance differential cover
The stock differential cover is the one that is already supplied by the vehicle manufacturer. The thing about stock differential covers is that they're made from pressed steel and as a result, they're not really suited to absorb damage. Not only that, they're designed to meet the minimum vehicle specifications of your vehicle so they can't handle high fluid pressure when you begin to tow heavy cargo.
On the other hand, performance differential covers are usually made from thick aluminum and because of that, they have a very high fluid capacity. This becomes really crucial when you begin to haul or tow stuff using your vehicle. Aside from that, increased fluid-carrying capabilities often lead to better engine performance.
Choose a differential cover with some or all of the following features:
- A magnetic drain plug and magnetic-tipped plug because these offer better rear-end protection while trapping worn gear material as well. The magnet basically sucks in any contaminants that may affect fluid integrity inside the differential.
- Internal and external fins for maximum fluid cooling.
- An integrated heat sink for superb heat reduction.
- A special powder coating for preventing corrosion and damage.
- Easy fill points so you won't have a hard time fixing it.
- It should be made with aluminum or stainless steel for maximum durability.
- A warranty so you can enjoy free servicing if any problems will arise after purchasing it.
- All the mounting hardware so you won't have a hard time installing it.
- Various designs to improve the looks of the rear portion of your vehicle. There are many differential covers out there that can change the look and style of your vehicle in an instant.
Some of the brands that you can consider if you're looking for replacement differential covers include AFE, ATS, Mag-Hytec, Outlaw, PML, PPE, and Strictly Diesel.
Steps to Easy Differential Cover Installation
A leaky differential cover can greatly affect the efficiency of your car's differential. This is why automotive experts recommend the prompt replacement of damaged or cracked differential covers.
Difficulty level: Difficult
Tools that you'll need:
- Torque wrench
- Razor blade
- Flat-head screwdriver
- Hammer (small)
- Funnel (small)
- Clean rags
- New differential gasket
- Putty knife or paint scraper
- Extensions and sockets (will be used to fit the bolts securing the differential cover)
- Floor jack and Jjck stands
- Gloves (rubber)
- Safety glasses
Step 1: Raise your vehicle using your floor jack and jack stands. If necessary, use wheel chocks on your front tires. Put on your eye goggles and gloves.
Step 2: Position cardboard or lots of newspaper underneath the differential cover to catch grease and dirt. Spray on degreaser on the cover and remove all signs of sludge.
Step 3: Place pan or basin beneath the rear end. Drain the fluid by removing the drain plug. Once fluid has been drained, remove all bolts on the rear end cover. If the bolts won't budge, use lubricant to loosen them. Clean these bolts.
Step 4: >Remove the cover. If the cover won't move, use your small hammer and putty knife or paint scraper to pry it loose. If you're planning on reusing your cover, clean the cover and its mating surfaces thoroughly.
Step 5: Put gasket sealer on the differential cover's mating surfaces and attach your new gasket. The holes on the gasket should line up with the cover's bolt holes. The gasket sealer should be about 1/8-inch thick. Also apply sealer onto the mating surface of your differential rear end. Wait for a few minutes to let the sealer set.
Step 6: Put the cover back onto the differential rear end. Hand-tighten each bolt, then use your torque wrench. If you're using a metal cover, torque should usually be at 25-35 pounds (lbs.). If you're using a plastic cover, torque is usually at 10-15 lbs.
Step 7: Remove the filler plug found on the top section of the rear end. Using your funnel, top off the chamber or container with new fluid.
Step 8: Clean the filler plug and replace onto the rear end.
Things to consider:
- Make sure your negative battery terminals are disconnected before starting this job.
- When working under your car, make sure you have ample lighting.
- The gasket is usually replaced each time the differential cover is removed.
- Check your differential fluid levels every 15,000 miles.