Best Oil for Harley Transmission – Top 5 Selection For 2023

by Lindsey Carter

All engines need oil for constant lubrication. Transmission oil makes sure all sensitive and vital components retain the integrity of the structure. The oil is the reason for pollutants exhaustion that keeps the motor running at its best.

Harley Davidson motorbikes are one of the most sought after bikes. They are known for being top of the line when it comes to touring and cruising.

Your Harley Davidson motorcycle is air-cooled that could get hot faster than a water-cooled motorcycle. The best oil for Harley transmission ensures that the motor runs at the best possible temperature.

Summary Table for Best Oil for Harley Transmission

Image Product Name Price

Red Line 42804 V-Twin Transmission Oil

Red Line 42804 V-Twin Transmission Oil

Price Check

Red Line 90226 V-Twin 20w50 PowerPack Oil

Red Line 90226 V-Twin 20w50 PowerPack Oil

Price Check

Bel-Ray Big Twin Transmission Oil

Bel-Ray Big Twin Transmission Oil

Price Check

Spectro Oil R.HDPG6

Spectro Oil R.HDPG6

Price Check

Maxima Racing Oils

Maxima Racing Oils

Price Check

The Best Oil for Harley Transmission Reviews

The Best Oil for Harley Transmission Reviews
The Best Oil for Harley Transmission Reviews

Selecting the best oil for your Harley Davidson is a must. You might think that all motorcycle engines are the same, and so people can use the same for all brands. Think again! Certain brands are particular when it comes to motor oil engine.

1. Red Line 42804 V-Twin Transmission Oil

Red Line 42804 V-Twin Transmission Oil
Red Line 42804 V-Twin Transmission Oil

For a motorbike rider, it can be disturbing to hear the gearbox make a noise as if it will fall off on your next gear shift. To be cautious, you have to be sure that your motor is as lubricated, and the oil it uses helps it endure extreme temperatures.

This motor oil is made primarily to be used in four-stroke ATVs and motocross. Because of how it effectively dampens the noise coming out of the transmission, it is famous for being shock-proof. What the oil does is reduce the shifting clunk in the gearboxes, thus eliminating that sound.

Between the gear teeth, the oil offers thick films that reduce friction. Also, this oil is responsible for shifting gears effortlessly.

Because of the viscosity characteristics of the oil, the firm thickness protects the gear. With that protection, the friction is also reduced; thus, prolonging usage before wear and tear become apparent.

Using this synthetic oil, you do not just go longer miles before an oil change requirement, but also it makes sure that your engine is in good shape during this extended period. Oil circulates in the engine and keeps it clean by collecting dirt and debris that could damage the motor.

Moreover, the oil helps reduce the temperature to decrease possibilities of overheating that could be detrimental to your motorbike's performance.

Another stand out feature of this oil is its color - pink. This color makes it easier for the driver to notice any leakage. Make sure you also check our guide for oil for the Duramax engine.

Highlighted Features

  • Effortless gear shifting
  • Highly efficient
  • High level of viscosity
  • Temperature reduction to avoid overheating

2. Red Line 90226 V-Twin 20w50 PowerPack Oil

Red Line 90226 V-Twin 20w50 PowerPack Oil
Red Line 90226 V-Twin 20w50 PowerPack Oil

If you are a hardcore biker, this oil powerpack is a huge relief. Not only is it economical, but it also offers excellent performance. For first-timers, the motorcycle chain oil is a big plus. Chain oils are often confused with substandard oils.

This synthetic engine oil performs better in areas with a hotter climate than usual. The oil composition helps keep the motor's temperature at its all-time low. Even with the low temperature, the viscosity of the oil remains uncompromised.

If you are an average user, this oil does a better job of making sure that the position is secured for V-Twin engine bikes.

This tune-up kit has everything that you can need to make sure that your engine runs smoothly and efficiently. It will provide you with a smoother ride, where gears shift easier and do not rattle as much.

The kit includes everything you need to change the oil on your own - a bottle of Supercool with WaterWetter, a bottle of Fuel Injection Cleaner for Motorcycles, 5 quarts of 20W50 Motorcycle Oil, a starter kit, a versatile funnel, and a Red Line Oil embroidered hat.

Each kit includes enough fluids for a complete change, although just to be sure, double-check the motor's capacity to avoid overfilling it with oil. Check out the most essential automotive parts of 80W90 Gear Oil

Highlighted Features

  • High-Revving four-stroke motor oils and gear oils
  • Motor oils have a high level of zinc and phosphorus for anti-wear
  • Exceptional friction modifier for better wet-clutch
  • Full synthetic oil with Ester and PAO base stocks
  • Gear oil reduces the thinning due to high temperatures

3. Bel-Ray Big Twin Transmission Oil

Bel-Ray Big Twin Transmission Oil
Bel-Ray Big Twin Transmission Oil

If you're looking for transmission oil that will not just offer smooth shifting of gears but can also maximize horsepower, you're in for a treat with this one.

Its manufacturer is known for its total performance products, and this one is specifically engineered for V-Twin Engines such as the Harley Davidson.

The multigrade transmission oil helps with the quieter engagement of the gear and smoother shifts.

To minimize friction and protect the sensitive components from shock, it has advanced additives and superior chemistry.

Because of the proprietary additives, the high quality of index oils provides oxidation protection and helps maintain film strength in a range of temperatures, even the higher levels.

The same additives reduce sliding friction for exceptionally quiet and smooth shifting of the gears.

This oil is made specifically for final drivers and those with Big Twin transmissions that require hypoid gear oil - standard and limited differential on slips and driveshaft transmissions. There is also superior shear stability due to the viscosity resisting the breakdown caused by gear shearing.

For maximum horsepower, the superior lubrication of the oil minimizes sliding friction, allowing maximum power in the motor.
Moreover, the distinct red helps the rider detect leakage easily.

Highlighted Features

  1. Quieter gear engagement and maximum horsepower
  2. To protect gears from shock loading, oil has extreme pressure chemistry
  3. Distinct color for leakage detection
  4. Film strength on different temperatures

4. Spectro Oil R.HDPG6

Spectro Oil R.HDPG6
Spectro Oil R.HDPG6

This unique oil and lubricant were developed and manufactured specifically for Harley drivers who do not like the noise coming out of their transmission. It allows for smoother shifting, eliminates the clunking, and reduces the whine on the fifth gear.

Furthermore, its exclusive G4 technology and special additives are for the additional anti-wear protection, better film strength in the gears, and it reduces the drag while it extends the life of the gear. Low friction, low drag loss viscosity reduces slipping and clutch drag.

Unlike others, the extreme heat and higher load do not affect the oil, letting it perform at its best when pushed hard. It contains a special polymer that provides stabilization in the temperature and exceptional engagement in the clutch.

This synthetic oil is also known to perform under every kind of weather conditions, extremely high temperatures, and heavy loads.
Furthermore, this oil would take thousands of miles before there is a need to change it. It collects dirt and debris as the engine circulates, ensuring that it's always clean.

Highlighted Features

  • Ideal for long-distance drivers as it works even in high temperatures and heavy load
  • G4 technology and additives protect the gear and bearings against wear and tear
  • Circulating oil cleans the engine by trapping debris, preventing motor damage
  • Silent and smooth shifting of gears and reduction of whining in the 5th gear

5. Maxima Racing Oils

Maxima Racing Oils
Maxima Racing Oils

Every rider needs a dependable oil that will take care of the engine and its parts. Look for one that allows smooth riding and extends the life of your engine.

A mineral-based oil that focuses on 4, 5, and 6-speed high-performance gears, this oil is perfect for your Harley.

It has a robust, and shear-stable kind of formulation that is designed specifically for the Harley transmission or any twin V model minus the wet-clutches.

This oil is of high film strength and allows protection against viscosity loss, shock, loads, and ordinary wear. With the extreme pressure additives as well as surface-active chemistry, smooth shifting under peak RPMs and loads is possible.

Also, it has ultra-clean detergents that protect the gears from deposits and wear, allowing for a hassle-free operation.

For better motorcycle performance in extreme and high-stress situations, this mineral oil is made with high-performance formula.

Combined with the religious maintenance, you can be confident that your motorcycle can take you places and will not die on you in the middle of a ride.

Highlighted Features

  • Mineral-Based gear oil
  • Perfect for the 4, 5, and 6-speed high-performance gearboxes
  • High film strength which provides excellent protection against shock loads, wear, and loss of viscosity
  • Extreme pressure additives and active chemistry for smooth shifting under RPMs and peak loads
  • Detergents are ultra-clean and protect gears from wear and operation that is trouble-free

Things to Consider Before Buying Oil for Harley Transmission

Best Oil For Harley Transmission
Best Oil For Harley Transmission

Any vehicle, especially motorbikes, experience all the possible stress that the road could give. Making sure that your engine works at its optimal, you have to make sure that the oil used to keep it moving, is top-notch.

Here are the things you have to look out for when doing your oil change:

Type of Motorcycle Oil

There are three motor oils to choose from: mineral oil, full synthetic, and semi-synthetic.

  • Mineral oil is refined crude oil. It could be less stable and may not be great for vehicles running at higher temperatures.
  • Full synthetic oil is made of various compounds blended. You can expect improved performance with this.
  • Semi-synthetic oil is a mix of synthetic compounds and crude oil. It gets the job done without breaking the bank.
  • No one would want to put oil that is not meant for their bike. Make sure you put the correct type of oil in your transmission.


The speed wherein the oil flows is referred to as viscosity. The lower the viscosity level, the oil flows freer and faster, while the higher viscosity means the opposite effect. Using the wrong viscosity could mean grinding of metal on metal.

Additives and Cleaning Capabilities

These additives work to remove debris and acid in the engine. Together with these, gunk can also form, mainly when the engine is used daily.

Cleaning this yourself means taking the engine apart, which could be tedious, time-consuming, and would require a skilled mechanic.

The cleaner the engine is, the better it runs for an extended time. The wrong type can damage the engine.


Your motorcycle is used multiple times on different weathers and terrains. Make sure to invest in products with longer shelf lives. Products with better quality tend to have longer shelf lives than substandard ones.

Reviews and Recommendation

Find your fellow Harley drivers. If it is your first Harley, it is better to speak with a seasoned driver and ask what they prefer on their bikes. Online reviews can also be a great place to go for recommendations.
Also, finding someone with the same bike as yours could be more convenient with a broader network, thus, getting more insight into how to take care of your motor.


The amount that you have to pay in taking care of your bike should be a consideration. If you pay for a higher price, this should improve the life and performance of your bike.

You might want to consider products that are multi-packed for additional savings. Also, look for oil with change kits, if you are certain that you can handle the maintenance yourself.

FAQs : Frequently Asked Questions & Answers

1. How many quarts does the transmission of a Harley Davidson take?

The amount of fluid depends on the fluid you select. Some fluids can be used in the engine, chaincase, and the tranny. As such, a quart of fluid should be enough for the Harley.

2. When and how often should I change my Harley's transmission oil?

According to the owner's manual, an oil change should take place at 5,000 miles. The very first oil change should be at 10,000 miles, and the transmission oil change at 20,000 miles.

For the transmission, an oil change should be done every year. Change the oil when it is warm, as it is easier to get rid of the debris and contaminants.

The frequency depends on how hard you are riding and the distance covered.

3. What kind of fluid should be used in a Harley Davidson transmission?

Harley Davidson is the one to certify your transmission fluid. This way, the warranty of the motorbike is not voided. Your transmission oil should endure extremely high temperatures, pressure, and load.

4. Is synthetic oil better to be used than standard oil?

If you use synthetic oil, you will need less oil change as you can ride your motorbike for thousands of miles before needing one.

Also, synthetic oil reduces transmission noise as the viscosity lubricates the gear teeth preventing friction that produces the noise.

Furthermore, synthetic oil works better in extreme weather conditions. It also prevents overheating and ensures perfect performance.

5. Are there times that synthetic oil should not be used?

You can use it anytime you want - whether for new or old engines.

Final Word

We have tried to round up everything there is to know about the best oil for Harley transmission. Knowing these things can help you make a sound judgment of what to look for and what to get for your ride.

Buy on Walmart

Spectro Oil R.HDPG6 Heavy Duty Platinum Full Synthetic 6spd Trans Lube 1 Quart - Walmart Link

Red Line 90226 Big Twin 20w50 Power Pack Oil Package (Complete Kit) - Walmart Link

Maxima Racing Oils 90-119016C Chrome Maxima 90-119016C Twin Cam Synthetic 20W-50 Chrome - Walmart Link

Life Guard Fluid 8 (7 Liter) - ZF PARTS - S671090312 - Walmart Link

RAVENOL J1D2113 ATF (Automatic Transmission Fluid) - 8 HP 8-Speed & 6-Speed Compatible - Walmart Link

Bel-Ray VTwin Primary Chaincase Lubricant - 1L. 96920-BT1 - Walmart Link

Red Line RED42804 V-Twin Transmission Oil, 1 Quart, 1 Pack - Walmart Link

Mobil (112812-4PK) Delvac Synthetic Transmission Fluid 50 - 1 Gallon, (Pack of 4) - Walmart Link

Buy on eBay

Spectro Oil R.HDPG6 Heavy Duty Platinum Full Synthetic 6spd Trans Lube 1 Quart - eBay Link

Red Line 90226 Big Twin 20w50 Power Pack Oil Package (Complete Kit) - eBay Link

Maxima Racing Oils 90-119016C Chrome Maxima 90-119016C Twin Cam Synthetic 20W-50 Chrome - eBay Link

Life Guard Fluid 8 (7 Liter) - ZF PARTS - S671090312 - eBay Link

RAVENOL J1D2113 ATF (Automatic Transmission Fluid) - 8 HP 8-Speed & 6-Speed Compatible - eBay Link

Bel-Ray VTwin Primary Chaincase Lubricant - 1L. 96920-BT1 - eBay Link

Red Line RED42804 V-Twin Transmission Oil, 1 Quart, 1 Pack - eBay Link

Mobil (112812-4PK) Delvac Synthetic Transmission Fluid 50 - 1 Gallon, (Pack of 4) - eBay Link

About Lindsey Carter

Lindsey and Mike C. grew up in the same neighborhood. They also went to the same Cholla Middle School together. The two famillies from time to time got together for BBQ parties...

Lindsey's family relocated to California after middle school. They occasiotnally emailed each other to update what's going on in their lives.

She received Software Engineering degree from U.C. San Francisco. While looking for work, she was guided by Mike for an engineering position at the company Mike is working for. Upon passing the job interview, Lindsey was so happy as now she could finally be back to where she'd like to grow old with.

Lindset occasionally guest posted for Mike, adding other flavors to the site while helping diverse his over-passion for baseball.

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