10 Best Sealant for Differential Cover in 2021 – Buying Guide

Best Sealant for Differential Cover

Choosing the best sealant for differential cover is important because sealing a differential cover is essential for the life and quality of your vehicle. Whether you are using a heavy truck or a simple jeep, you need to service your gears and change fluid from time to time.

The two matting metal surfaces of differential opening and cover fail to contain the oil. If there is no gasket or an RTV layer between them, it will leak.

The differential cover may also leak as the metal surface becomes abrasive with time due to scratches, and there are small gaps between the mating surface. The liquid can seep through even seals if you don’t use the good quality differential sealant.

RTV sealants are considered to be the best for sealing the differential cover. They are durable and provide resistance against high temperature, water, and other contamination.

In this article, we will look at some of the great quality sealants for differential covers and give a detailed buying guide. We have tried to answer all your questions about how to seal differential cover and all relating questions.

Quick Comparison: Best Sealants for Differential Cover

Top 10 Best Sealant for Differential Cover Reviews:

1. Loctite High Flex Silicone Sealant for Differential Cover

Loctite High Flex Silicone Sealant for Differential Cover

Loctite Sealant is a silicon adhesive perfect to be used for joining the differential cover. It’s a waterproof sealant that prevents any moisture from reaching inside the differential.

Besides being useful for differential cover, Loctite sealant is a multipurpose adhesive used with metal, glass, rubber, tile, or porcelain.

The best part of having Loctite sealant is its power to keep the two ends joined together under any conditions. It’s an impact-resistant adhesive that flexes with material and won’t allow any contamination inside the differential.

The sealing stays intact for a long. It does not crack, peel, or shrink with time at all. It fills all the gaps between the nuts and keeps them sealed against all environmental effects.

The sealant is highly temperature resistant. It will not come off even when your vehicle is burning hot. It forms a sealed layer when cured for up to 24 hours and resists oils and lubricants from leaking.

The sealant cures with time on its own. It cures into a flexible resin that works better than any gasket material.

The Loctite sealant works well for uneven spaces as well. However, you should keep in mind that it becomes difficult to remove once it locks the seal. It does not come apart easily as any other silicone and needs a lot of force.

 Pros:

 Cons:

  • Flexible resin seals better than gasket cover

  • Temperature resistant

  • Makes waterproof seal

  • It does not shrink or crack easily

  • Multipurpose use

  • Clears silicone differential sealant

  • It can be uncomfortable and difficult to remove if cures on any other material easily

  • It takes 24 hours to gain full strength

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2. Ford Genuine Silicone Differential Cover Sealant

Ford Genuine Silicone Differential Cover Sealant

This one is particularly useful for sealing heavy truck’s differential covers. It’s a specifically designed alkoxy cure RTV sealant for high-temperature applications.

It’s a non-corrosive differential sealant that protects the metal from corrosion. The seal resists water or any other particles entering through the differential cover. The sealant is by far provides a better seal than the gasket.

The differential sealant is specifically made to be used with 7.3L Power Stroke, 6.01 and 6.4L diesel engines. The sealant comes in a 5 oz bottle that is easy to use. You can also use it through a grease gun as well.

The drying time of this silicone sealant is also less. It requires no more than 2 to 4 hours to cure completely.

However, drying time may vary depending on how thick you have applied. For sealing a gasket, it takes no more than 15 minutes.

Overall, we can call it a very good sealant for differential cover due to its durability and resistance. You don’t need too much to seal the differential cover, and the bottle will be there to be used for different house use as well.

 Pros:

 Cons:

  • Easy to use

  • 5 oz bottle means you won't leave much to waste

  • Dries in less time

  • Tough and durable seal

  • Good shelf life

  • Perfect for high-temperature applications

  • Strong adhesive is hard to clean off

  • You may end up pouring too much with the tube

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3. J-B Weld Black Silicone Sealant for Differential Cover

J-B Weld Black Silicone Sealant for Differential Cover

Here is another sealant that you can use for sealing differential cover. It’s a multipurpose sealant that is designed for mechanical assemblies. It seals the area perfectly even at high temperatures up to 550o-650o F.

Besides differential covers, it can be used for diverse purposes. You can use it for building, mechanicals, and for repairing various surfaces strongly.

The adhesive resists gas, oil, diesel, and other automobile fluids. Besides sealing metal to metal objects, it can bond porcelain, ceramic, glass, marble, PVC, and any other type of material.

The seal is easy to use and cure within less time. The seal is waterproof and also resists any other lubricants. It won’t shrink, dry, or crack and is sensor safe as well.

A common problem with all sealant tubs and bottles is that they can be stuck and dry in the opening and are difficult to use. You can close the opening with a piece of aluminum foil and keep using the sealant for a long time.

The bottle contains 9.5ounces of fluid but is also available in a bigger bottle. The differential sealant is available in three colors; black, red, and grey.

 Pros:

 Cons:

  • Strong and durable adhesive

  • It does not shrinks or cracks

  • Cures easily within less time

  • Offers multiple uses

  • Resists water, oil, diesel or any other fluids

  • If you don't use 9.5 oz so you can buy a smaller tube

  • It gives a bad odor

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4. Pro Seal N80729 Red RTV Gasket Sealant

Pro Seal N80729 Red RTV Gasket Sealant

Pro Seal is another RTV silicone sealant for differential cover. It’s made for high-temperature applications and offers quick repair.

The seal can withstand a temperature between 70-650 Fahrenheit. Besides high temperatures, the seal remains intact even in low temperatures. It is anti-freezing quality makes it suitable to work in any weather condition.

It’s a high-quality sealant that resists dust, oil, fuels, diesel, grease, and transmission fluids as well. The sealant, once cured, is flexible. It does not shrink or crack under pressure or any other impact.

That’s quite a nuisance if you have it in your garage and use it once in a while. It can take several minutes to extract the hardened silicone out of the nozzle.

Overall, it’s a good sealant. Price is a bit high, especially when we compare with other sealants on our list. It takes almost two hours to cure.

The big bottle stays useful for a long time. You can use it for differential cover and other house repair needs.

 Pros:

 Cons:

  • Can resist high pressure

  • Anti-freezing quality

  • Can withstand high temperature

  • Provides flexible seal

  • Good RTV gasket maker

  • Multipurpose use

  • Dries in the nozzle

  • Difficult to remove when cures properly

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5. J-B Weld Blue RTV Gasket Maker Differential Cover Sealant

J-B Weld Blue RTV Gasket Maker Differential Cover Sealant

This one is another general-purpose RTV silicone sealant to use on differential cover and multiple tasks at home. The sealant is excellent for uneven surfaces.

It’s an excellent choice for both professionals, DIY people, or home users. The sealant creates a strong and tough seal on any surface and resists moisture.

The RTV gasket maker is easy to use. It comes in bottle form and is easy to apply. Unlike a tube, you can easily detach the nozzle and clean it if the silicone clogs it.

The sealant takes less time to cure. Once it is perfectly cured, the sealant does not crack, weather, or shrink. It can handle pressure well as well.

Removing it can be a little difficult due to its tough seal. Besides the differential cover, it is great for sealing other automobile accessories as well.

The sealant comes in blue color, though you can find other sealants of J.B Welds if you are looking for a red or grey color.

Overall, it’s a good option for those looking for a tough and weatherproof sealant for differential cover. It works well in any weather and remains tough under high pressure or temperature.

 Pros:

 Cons:

  • Tough sealant

  • Easy to use

  • Weather-resistant

  • Waterproof sealing

  • Easy to store and reuse

  • If you need only differential cover, you may not need the whole bottle

  • It takes longer to cure perfectly

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6. Permatex 80011 Black Sealant for Differential Cover

Permatex 80011 Black Sealant for Differential Cover

Here is another gasket maker for automobiles that you can consider for sealing your differential cover.

The sealant provides a non-hardened seal that is tough enough to keep your differential cover tight and easy to disable. The somewhat soft silicone is easy to remove when you want to access the differential.

The sealant is made for joining valve cover gaskets and oil pans, but you can use it pretty much for any material that needs sturdy but flexible sealing.

The sealing with Prematax is not something you would complain about. Using it is very simple. Like any other RTV, you need to apply the thin and even layering on all sides of the cover and apply when it starts to get thick.

The seal is resistant to both heat and cold. It can stay in perfect condition at -65-400 degrees Fahrenheit.

Unlike the other silicone sealant that is hard and thick, it remains rubber-like. The sealing it provides is waterproof. It can handle pressure and stay intact for as long as you try to detach the sealing. The curing may take some time.

 Pros:

 Cons:

  • Great for oil pans and differential cover

  • It remains rubber-like on curing

  • Needs only a thin film to work

  • High temperature resistant

  • Prevent oils and fluids from leaking

  • Easy to detach when you need to remove the cover

  • Takes a long to cure

  • Seals only metal objects

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7. Genuine Chrysler RTV Silicone Rubber Adhesive Engine Sealant

Genuine Chrysler RTV Silicone Rubber Adhesive Engine Sealant

Genuine Chrysler provides another RTV sealant that is specifically designed for automobiles. It’s a durable rubber adhesive sealant for the engine, oil pan, and differential cover.

The black sealant is formulated to stay useful even under high pressure. Its anti-freezing and high-temperature resistant qualities make it suitable for all-year use.

It provides a perfect seal and won’t allow any fluids to seep in or out under any conditions. The seal is easy to detach, so it won’t give you a hard time when you want to remove the cover next time.

The sealant comes in a small bottle. The 3 oz bottle is enough to be used for gasket making. You can use the rest for other purposes as well.

As it’s a silicone sealant, it works on any other material as well. You can use it to repair kitchen sinks, window seals, or any other material for sealing.

Overall, it’s a cost-effective option for those who don’t want to buy big bottles. The sealant does its job well, and you can use it for diverse purposes in both home and garage.

 Pros:

 Cons:

  • It comes in a smaller package

  • Easy to use tube

  • Provides waterproof seal

  • Works well on high temperature

  • Specifically formulated for automobiles

  • Bit pricey, especially considering its less quantity

  • The nozzle it comes with is not very durable

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8. Permatex 27036 Differential Cover Gasket Maker Sealant

Permatex 27036 Differential Cover Gasket Maker Sealant

This one is another premium quality RTV sealant from Permatex. It’s a grey gasket maker and sensor-safe seal. The seal is perfectly safe for the metal-made differential cover and does not cause corrosion.

The silicone seal it provides is maximum vibration resistant. Not only that, but it prevents dust, oil, water, or any fluids from entering in or through the seal.

The gasket maker remains secure even in high temperatures. The heavy load on trucks and other loaders can increase the temperature in the differential. A sealant should be able to withstand high temperatures.

Permatex sealant remains unaffected even in extreme weather conditions. It has a temperature tolerance between -65o-7000 F.

A clogged nozzle is a common issue you have to face while working with these sealants. This one comes with two nozzles so that you can use the sealant for multiple purposes later.

The sealant may take some time to cure. It can take almost a day to get fully cured. Once fully cured, it gets hardened and remains fixed for as long as you require.

Even detaching the covering or oil pan can become a little difficult, and you need full force to detach the seal.

 Pros:

 Cons:

  • Easy to apply

  • It comes in tube form with nozzles

  • Gear Oil RTV

  • Withstand up to 700 degrees Fahrenheit

  • Waterproof seal

  • Maximum sensor resistant

  • Non-corrosive sealant

  • It gives a strong seal, and removing the cover may take force

  • Difficult to scrap off

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9. Permatex RTV Gasket Maker & Sealant for Differential Cover

Permatex RTV Gasket Maker & Sealant for Differential Cover

This one is specifically formulated for gear oil. The gasket maker can withstand the harsh oil environment found in differentials. It forms a silicone seal that does not break down even under pressure. It remains intact with the oil friction modifiers.

As compared to a silicone gasket, it seals the path perfectly well. Unlike a gasket that can be easily moved or leave spaces, this one completely blocks the way allowing no fluids oil. The seal is also waterproof.

It’s a non-corrosive sealant. If your differential case has scratches and dents around it, clean it with sandpaper and then apply it evenly. It works well on uneven spaces as well.

Though formulated for greasy oils, the sealant can be used for sealing other metallic and non-metallic objects. The leftover sealant can be later used and does not solidify if you have put the cover back tightly.

 Pros:

 Cons:

  • Multipurpose gasket maker

  • Stays flexible on curing

  • Makes waterproof seal

  • Withstand high temperature

  • Resists oil and water

  • Anti-freezing sealing

  • It dries too quickly, so you have to fix the pieces in place quickly

  • Works well only if you have cleaned the surface from both sides before applying it

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10. Visbella Anti-Freeze Natural Sealant for Differential Cover

Visbella Anti-Freeze Natural Sealant for Differential Cover

The last one on our list is from Visbella. It’s a high-quality sealant formulated for automobiles. It’s a sensor-safe seal used on the differential cover or any other metal part of an automobile.

The RTV seal is water and oil-resistant. It can handle the heavy temperature inside differentials and remains in good condition even under pressure.

It increases the life and performance of your vehicle by not allowing any pressure or dust particles to get through to the essential parts of the differential. The Visbella seal remains flexible on curing.

However, it seals the parts perfectly but allows you to take off the seal once you need to remove it. The seal is high temperature resistant and can withstand up to 600 degrees Fahrenheit.

It also has anti-freezing quality, so that means you can use it in any weather. The sealant is also non-corrosive, and it stays good as long as you want.

Overall, it’s a multipurpose RTV gasket maker that you must have in the garage. It can be useful for mechanics for several applications like engines, motors, gear pumps, high-temperature piping systems, or air compressors. It takes some time in curing but gives the best seal for long.

 Pros:

 Cons:

  • Multipurpose gasket maker

  • Stays flexible on curing

  • Makes waterproof seal

  • Withstand high temperature

  • Resists oil and water

  • Anti-freezing sealing

  • It dries too quickly, so you have to fix the pieces in place quickly

  • Works well only if you have cleaned the surface from both sides before applying it

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Best Sealant for Differential Cover: Buying Guide

Here we have rounded up the things you should consider while selecting a sealant for your differential cover.

Consistency

The differential cover sealant comes in a gel-like consistency. You can look for the right consistency by using different sealants.

If it’s too runny, you may end up using more than you wanted. So look for a sealant that is easy to use.

Color

Silicone sealants are available in many colors like black, grey, red, or transparent. It hardly matters if you are using it on the differential cover, but you can use the grey color that suits the aluminum cover.

However, you can use any color as long as it is sealing the cover properly

Withstand High Temperature

The temperature in the differential can rise, especially in trucks and jeeps, due to the heavy load they are carrying. And they have oil and fluids in the differential that can spike up the heat and cause any ordinary sealant to melt.

So you should choose the sealant that can withstand high temperatures. It should also have anti-freezing quality as in many areas, the temperature drops to minus degrees in winter.

Pressure and Abrasion Resistant

When you have high pressure inside the differential due to the heat, temperature, and fluids, the oil can cause friction against the rubber-like seal.

Differential cover sealant gives in easily if the seal cannot withstand pressure and abrasion, so you need a foolproof differential cover sealant.

Easy to Apply

The silicone sealant comes in bot bottle and tube form. For the differential cover, you can choose a small tube form. It is easy to apply, and you can save the rest for other purposes. The only trouble one may encounter is the clogged nozzle next time you want to use it.

For that, you should clear the nozzle opening of the differential cover sealant and cover the tube with plastic or aluminum foil. Leaving the nozzle on can result in drying out the sealant and rendering it almost useless.

Water and Fluid Resistant

A sealant should seal the cover completely, allowing no leaks from any side. It should be oil and fluid-resistant.

Curing Time

Some silicone sealants take almost the whole day to cure fully. So make sure you check the curing time before selecting the RTV sealant. It may take some time, but few hours are enough, and it chooses the

Easy Removing

We are specifically talking about the differential cover, so you may need to remove it again to change the oil. So make sure the seal does not give you a hard time removing the cover next time you want to access differential.

However, given that the strong bond it provides, a sealant can become difficult to remove. Removing both front and rear differential sealant can be difficult. You can always use a sealant remover that makes the task easier.

What is a Differential Cover?

The differential opening is the place from where you can access the gears. The differential has oil to keep the gears lubricated, or they may cause friction, vibration while driving, or loud noises.

You need to change the oil in differential from time to time. You may also need the opening for the service or repair.

A differential cover allows you to access the inside of the differential.  You can change oil through it or use it to access gears or other parts.

Differential cover plays a great role in the performance of your vehicle. The cover gives protection to your vehicle’s front and rear differential. The metal-constructed covers usually have reinforced ribs that give them maximum strength.

Not only it provides an opening to access the fluids inside the gears, but the differential cover also plays an important role in dissipating the heat and protect the gears from contaminations like dust, water, fluids, and rocks.

Hauling load can add a lot of heat and stress to your differential cover, especially when it contacts rocks and other debris on the road.

That is why upgrading differential from time to time is essential to add power to your vehicle. Heavy trucks need front and rear differential sealants.

What is a Sealant?

Sealant is a type of adhesive used to create a water and air-tight seal between two surfaces. It’s like the glue that binds together two parts and won’t allow fluids to leak in or out from both sides.

Sealants come in different types like caulk or mastics. Depending on the type of sealant you have chosen, they can become hard or remain rubber-like on curing.

Silicone sealant is specifically formulated to make a gasket between metal pieces so that the liquid does not seep out. It has a gel-like consistency and becomes strong but flexible on curing.

How to Seal a Differential Cover Correctly?

Let’s see how to seal a differential cover to change the gear oils. Here is a step by step guide for both front and rear differential sealants:

  • Remove the differential cover.
  • Make sure you place a catch basin or a bucket underneath, or it will spill oil all around.
  • Remove all the bolts except for the bolt above so that fluid inside drains out properly.
  • Once you have drained out all liquid, remove the last bolt and take off the cover.
  • Scrap the gasket from all sides of the cover and differential
  • Before you cover the differential again, you need to clean both mating surfaces to make sure it seals properly.
  • Don’t use a metal brush that can be abrasive for the metal. You can use a brush with nylon bristles to clean the area. After using the brush, clean it with a paper towel too.
  • Cut the nozzle of sealant you have chosen to seal the cover.
  • You can create circles around each bold holder. Connect each circle with the other one through a thin line. You don’t need to use too much sealant but make sure the application is even on all sides.
  • You don’t need to apply a sealer on both sides.
  • Once you are done with applying the sealant, you can give it a little rest. It depends on the sealant you are working with; some sealants take longer to cure. Once the sealant is a little thick, put the cover back on the differential. Thread a few bolts to alight the cover and later tighten all the bolts.

What is the Difference between Gasket and Seal?

A differential cover gasket is a rubber-like ring or sheet that is made to join two surfaces and prevent leakage. The gasket can be made from different materials depending on where you need its application.

Seal, on the other hand, does the same and has a broader category and includes o-rings. These are used on parts that rotate like engines, motors, or rotary pumps. Seals can be flat and round.

Both seal and gasket are made of different materials depending on the application where they are to be used.

What are the Different Types of Sealants?

Latex Sealant

These are water-based sealants. The good thing about them is that you can paint on them and thus are aesthetically appealing. However, these are not used for broader applications. You can use them to fill in the gaps.

These are easy to apply and should not be used where you need a waterproof sealant as they can shrink with time.

Acrylic Sealant

Acrylic sealants are U.V. stable. They don’t shrink and are durable for many substrates.

However, these sealants are not flexible and do not allow movements. They have a life span between 5-10 years.

Butyl Sealants

These are low-cost sealants and adhere to many substrates. These sealants are not very easy to apply due to their consistency.

However, these are waterproof and allow limited movement. Butyl sealants are also U.V. stable. They, too, last up to 5-10 years.

Polysulfide Sealants

Polysulfide solutions are flexible as they retain their elasticity on curing. They are good to be used in cold places as the elasticity retain itself even on very low temperature.

These sealants do not shrink and are also U.V. stable. Their life expectancy is up to 15-20 years. These are expensive sealants if we compare the price with other sealants.

Polyurethane Sealants

These are very common sealants. They offer strong adhesion and are abrasion-resistant. Polyurethane sealants adhere to many substrates and are easy to apply.

Silicone Sealants

These are common sealants used for home repair and improvement. As silicone sealants become rubber-like on curing, they are flexible and allow movement. They offer durable and strong seals and are water and other fluids resistant as well.

However, silicone sealant takes a long to cure. They can also be expensive but are abrasion and pressure resistant.

Why it’s important to sealing differential cover correctly?

Differential cover is essential to prevent leakage of the fluids inside the diff. It keeps the differential fluid inside and protects the gears and fluid from contamination like dust, rocks, water, or other particles. 

A cover gives access to differential and allows you to change the oil. So the opening is important, and you need to service the vehicle from time to time.

So, sealing with good quality RTV or differential cover gasket is essential to prevent leakage and protect your gears.

The metal sides of mating surfaces may have an uneven surface due to abrasion and corrosion. Sealing with RTV fills the gap and prevents any leakage. It also:

  • Protect the gears inside
  • Keep the fluid from leakage
  • Protect the fluids from dust, water, and other contamination
  • Allows easy access to differential next time you want to service the parts

Here’s our another latest guide: 10 Best Car Windshield Squeegee Reviews in 2021.

How to Stop Differential from Leaking?

To stop the differential from leaking, you should use a high-quality RTV sealant or a differential cover gasket to seal the cover. Clean both mating surfaces. It may have the remaining RTV still attached to it, so you need to scrape it off the cover and the sides of the differential opening.

Apply the RTV in equal consistency; you don’t need to put too much. Follow the path.

Let the RTV cure for a while; once it starts getting thicker, put the cover back in its place and tighten the bolts. Excess RTV should come out of the cover once you press it, and you can remove it.

Let the substance cure. It may take several hours for silicone RTV to cure. Curing time depends on the type of RTV you are using.

Frequently Asked Questions

1. What do you Seal a Differential Cover With?

A differential cover can be sealed with a silicone gasket or with an RTV sealant. Gaskets are ready to use. They come in the shape of a differential cover, and you just need to place it over the cover before you secure the bolts.

RTV sealants are a more popular way to seal the differential cover. It is durable and strong. Applying the sealant is also easy, and the seal it provides is water and another fluid resistant.

2. Can you Drive with a Leaking Differential?

Yes, you can drive with a leaking differential. However, once leakage starts, it will progress to full leakage, and you may notice puddles of fluid under your vehicle.

It may lead to some potential problems like whining or howling sounds from the gears. So a timely service to your vehicle is essential to keep it in good condition.

3. When Should I Flush my Differential Fluids?

It differs from what type of vehicle you are using. Generally, you need to change the differential fluid every 30,000 to 60,000 miles. You can also look for the signs like:

  • Oil changes color
  • Grinding and whining noise from vehicle
  • Vibration felt while driving

Final Words

Changing differential oil from time to time is essential for your vehicle. A differential cover should be sealed properly each time to prevent leakage. It should also prevent any contaminations from entering the differential where they can harm your gears.

Although all sealants in our list of the best sealants for differential cover are carefully selected for you, they may differ in price, color, and consistency. Still, they apply a good seal and are resistant to weather, water, dust, or other particles.

Still, not all sealants are equal, and we certainly have our favorite. We choose Permatex 27036 as our best bet due to its long-term durability and ease of use.

The sealant takes less time in curing and offers resistance to all external and internal elements protecting your gears and thus enhancing the life span of your vehicle.

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