Best Primary Oil For Harley: Updated 2023

Are you looking for a product to help make your life easier? We are for you. In the market, you can find various products that vary in features and specifications. In addition, it’s essential to choose the best primary oil for Harley Davidson. Choosing the right one from different Primary oil brands for your bike can be challenging.

Our following guide can help you to choose the best primary oil for your Harley. So, if you want to select a sturdy, durable product, you can follow our article. However, let’s first know what is primarily oil.

What Is Primary Oil For Harley Davidson?

For your Harley-Davidson, you need to use primary oil. The Primary oil consists of additives and petroleum. If you pump it, first, it goes from the crankcase to the transmission and then to the clutch.

Also, this oil helps to cool the engine by carrying heat away from critical elements. However, over time, this oil also breaks down and becomes ineffective. That’s why you need to change this oil frequently.

Best Primary Oil For Harley

Best Primary Oil For Harley Davidson:

There are numerous products on the market. But before choosing the best primary oil for your Harley, you should consider many things. First, select a primary oil with the optimal additive and viscosity. Check the owner’s manual to see what viscosity level your Harley motorcycle requires.

Second, before choosing the best one, consider the price. It’s because you don’t want to spend extra money, and you want to maintain quality. Nevertheless, let’s discuss some best primary oils for Harley Davidson with the best quality and price.

Mobil 1 Racing 4T 10w40 Primary Motorcycle Oil

Mobil 1 Racing 4T 10w40 motorcycle oil helps provide exceptional performance. It helps to keep your engines running smoothly and cleanly. Usually, it offers the best protection in extreme operating conditions. This oil combines a balanced equipment system and high-performance synthetic base stock. It can provide outstanding cleanliness, fantastic wear, and corrosion protection.

The most important thing is that this oil can extend your engine life and can minimize deposit formation. Ultimately, this oil is best for Harley and high-performance motorcycles. Due to its synthetic technology, this oil can maintain maximum power output. Overall, the specially engineered oil helps to provide outstanding performance in all seasons.

Formula + Transmission and Primary Chaincase Lubricant

This oil’s proprietary mineral base stock is Formula and tested-certified by Harley-Davidson® Motor Company. The Formula is mixed to deliver lubricity for the anti-wear requirements of transmission gears. This oil has an 84-later Big twin model with a wet-type diaphragm spring clutch.

For uses of primary Chaincase, you should change this oil every 10,000 miles before winter. Besides this, it can maintain the coefficient of friction. Also, this fantastic primary oil gives sufficient lubrication to the Primary chain for adequate clutch operation.

Moreover, this lubricant is approved for use in all primary chaincase life and transmission stages. But note that don’t use this lubricant in crankcases as motor oil. This Primary Chaincase Lubricant is one of the best options for people looking for the best primary oil.

Red Line (42904) V-Twin Full Synthetic Primary Case Oil

The primary oil on your Harley is just as crucial as the engine and transmission oil. V-Twin primary oil can operate over a wide range of temperatures. Also, it improves clutch operation, lowering wear and temperature and running smoothly.

Specifically, this oil was used in 1984 to present American V-Twin bike engines. Even the product is best used on primary chain cases with spring clutches. Likewise, this lubricant is also suitable for use in ATVs, power sports, and motorcycles. The Red-line was established in 1979, and they perform better than any on the market.

AMSOIL Synthetic V-Twin Primary Fluid

Amsoil V-twin primary oil is our other best option for Harley Davidson. This is also one of the best Harley primary oils that provides the best mileage between oil changes.

Furthermore, on Harleys, it acts as a compensator and shock absorber. That’s why the vibration of the engine doesn’t affect the transmission. Compensator wear often leads your machine to a kicking and knocking sound.

Notably,/Amsoil primary oil also adheres to the chain for better wear protection. Plus, its excellent wet-clutch-compatible formulation fulfills your JASO MA/MA2 requirements. Remarkably, this is the best Harley oil hot weather. So, if you live in hot weather, you can get better benefits from this oil.

You Can Check: Redline Oil Vs Amsoil

When it comes to Harley Davidson primary oil, you know several choices. Without the above, you can use Mobil 1 V-Twin 20W-50. Yet, some other best primary oil for your Harley is:

  • Lucas Oil 10790 Primary Chain Case Oil
  • Motorcycle Primary Case Oil Fill Funnel
  • And Red Wing Heritage Mink Oil is also the best oil and more.

Best Oil For Harley Transmission And Primary:

AMSOIL now delivers the best fluids for Harley Davidson primary chaincase and transmissions. These are called AMSOIL V-Twin Primary and Transmission Oil.

AMSOIL V-Twin 20W-50 is an excellent all-around lubricant for motorcycles. It is designed for use as Primary & engine oil and even transmission oil. It provides superior engine protection because of its proven ability to combat wear, maintain cleanliness, and prevent corrosion during storage.

It is a very efficient and convenient choice for all three components. V-Twin Primary and V-Twin Transmission Fluids will provide outstanding performance and protection for those who prefer specialized fluids.

Best Primary Oil For Harley 6 Speed:

George said in the Hollywood movie, “This? This is Harley Davidson. It’s the damn bike ever made” we really couldn’t agree with him. If you want this motorcycle but need clarification about the best primary oil, we will help you. Here we have discussed the best option for your Harley 6-speed motorcycle.

Bel-Ray VTwin Primary Chinese Lubricant

Primary Chaincase Lubricant from Bel-Ray is an excellent choice for your Harley Davidson. The oil is specially developed for the Primary big twin motorcycles.

Ideally, the product is suitable to withstand high pressure. Mainly, it also gives improved lubrication to your clutch to prevent slipping.

The complete Bel-Ray anti-wear chemistry ensures long service life for the primary chain. For enhanced performance, this oil comes with improved oxidation protection. Even so, this prevents clutch slipping for consistent engagement. Since the 70s, this oil has been in the market, and users loved this oil’s different sicknesses.

RedLine 90226 Big Twin 20W50 PowerPack Oil

People looking for cool operating temperatures and low noise can depend on this Red Line. This brand comes with a powerpack, an excellent choice for a six-speed Harley Davidson.

The price of the complete package is much lower than the total market value of the products included. Thus this budget-friendliness has made this product more famous in the market. Without this budget, another fact is that it stops and runs very well in southern heat and winter weather.

Customers love how the Red Line oil makes the transmission noticeably quieter, and no massive clunk can be found. They can easily control the tranny oil level. Hence, If it gets sticky, you’ll know you’re low on tranny oil.

Red Line RED42804 V-Twin Transmission Oil

The brand Red Line is one of the best products among Americans. This product is entirely different from the conventional lubricant. For that reason, the users claim they don’t want to try anything else after using this oil.

Frequently, this V-twin transmission oil comes to reduce the infamous shifting clunk found in gearboxes. Subsequently, to improve the performance, the oil reduces temperaturItlly. In fact, it delivers a thicker oil film between the gear teeth.

By accomplishing all the functions mentioned above, oil reduces transmission noise. The company uses state-of-the-art technology while manufacturing the oil. Additionally, the oil has been specially engineered to match the four-stroke motocross bikes.

Primary Oil Vs. Engine Oil Harley:

Most V-twin motorcycles, like modern Indian bikes, use a shared sump. They use the same lubricant, primary Chaincase, and transmission for their engine. But, Most Harley Davidson bikes use a separate sump for each oil.

AMSOIL makes 20W-50 synthetic V-twin motorcycle oil that is an excellent all-around lubricant. It provides outstanding engine protection due to its proven ability to combat wear and maintain cleanliness during storage. Synthetic V-Twin engine oil also boasts a shear-stabilized formulation.

Despite high-rpm transmission gears’ severe pressure and churning action, it withstands viscosity loss. Therefore, it provides dependable transmission protection. Synthetic V-twin motorcycle oil fulfills JASO MA/MA2 standards. And the wet-clutch compatibility offers excellent performance in primary chaincases.

In contrast, synthetic V-Twin primary oil has a higher viscosity than 20W-50 synthetic V-Twin motorcycle oil. A high-viscosity offers some benefits to help quiet noisy transmission gears.

FAQ (Frequently Asked Questions):

Q. Is Harley’s primary oil the same as engine oil?

Harley-Davidson motorcycles need a different type of oil called ‘primary oil. This oil is extra from engine oil. Actually, the work of Primary oil lubricates the engine moving parts and cools the engine. In contrast, engine oil can lubricate the moving parts inside the transmission. Harley always recommends you utilize a unique type of oil for each application.

Q. What oil does Harley recommend for primary?

For primary, there are several choices in the market. But from numerous options, Harley recommended the best primary oil. Harley suggested Formula + Transmission and Primary Chaincase and Mobil 1 racing 4T 10w40, which are ideal for Harley Davidson. Besides this, you can use Amsoil 20w50 synthetic oil, Quicksilver V-Twin Primary Chaincase, Transmission Fluid, etc.

Q. Can you use synthetic oil in Harley primary?

The best lubricant for your precious Harley Davidson engine is synthetic oil. However, there are other options, like mineral and semi-synthetic. But if you want the best results, use synthetic oil for your Harley primary. On the contrary, synthetic V-twin will fulfill JASO MA/MA2/standards. And it will be the best one for your primary.

Q. Can I Use Gear Oil In Harley Primary?

Accordingly, you can use 75W-140 gear oil in Harley-Davidson transmissions. However, 75W-140 is much thicker than the oil typically used in Harley transmissions. For example, AMSOIL V-Twin Synthetic Transmission Oil is an SAE 110 gear oil.

Gear oils contain heavy doses of “extreme pressure additives. And most people believe they can prevent wear in transmission and provide the best operation. Again, Amsoil 20w50 motorcycle oil has additives to avoid wear on gears, clutches, and chains. And there is no wrong side to using this 20w50 oil.

Some Harleys use the primary chain case’s automatic transmission fluid (ATF). We don’t recommend this option. Similarly, look at the actual viscosity numbers to back this up.

Final Word

There are many brands to choose from in the global and local markets. But not all of them will provide you with the primary oil for Harley Davidson. The key is to find a good brand that offers value and quality for your purchase.

When choosing a good brand, consider customer reviews, warranty policies, how long they’ve been around, and more. We hope this post can help you narrow down your search. And you can easily choose the best primary oil for Harley Davidson.



Rio is a car & motorcycle mechanic who is working with different kinds of problems relating to oil and grease. He is also a passionate technical writer.