Best Transmission Oil For Harley 6 Speed [Reviews 2022]

If quality, performance & consistency could’ve been defined with a single brand, then probably I would’ve named it Harley Davidson. As the brand itself is one of the best, so rhetorically, its requirement for the best transmission oil for Harley 6 speed nothing unusual for sure.

The right transmission oil is perfectly capable of minimizing the accumulated heat of the engine. Moreover, the functionality of the engine or its smoothness of operation to a certain extent depends on the transmission oil.

Here I am going to tell you about some of the transmission oil for your Harley Davidson that pushes the bike to reach a better performance level with more ease.

Best Transmission Oil for Harley Davidson

There is specific synthetic oil available for boosting your engine performance. Here is a brief discussion of our best 5 picks of best transmission oil for Harley 6 speed.

1. Spectro Oil R.HDPG6 Heavy Duty Platinum Full Synthetic 6spd

Some transmission oil specially formulated to offer better service on some specific bikes. This one is for the Haley bikes. If you are not happy with the noisy 6-speed transmission, then this synthetic Trans Lube is for you. It is a heavy-duty transmission that comes with G4 technology. Wear and tear of the bearing are a problem for the engine that can be solved with this technology of oil.

To strengthen between gear teeth some transmission oil comes to offer superior performance, especially for the Harley Davidson bike. To extend the life of engine transmission gear you must get this oil.  This oil is perfect that perform well under every type of weather.

Most of the users of this oil do not need to change this oil after a few miles of the urn. Before you change, it will perform for a thousand miles. To minimize the sound with a smooth-shifting, the owner of Harley Davidson can use this transmission oil.

  • Helps to clean the engine
  • Protect engine gear and bearing
  • Smooth and silent shifting
  • Ideal for long-distance riders
  • Extend gear life
  • A bit expensive

Available On Amazon

2. Maxima Racing Oils Chrome 90-119016C Twin Cam Synthetic 20W-50 Filter Complete Oil Change Kit

This is the right choice for you if you are looking for the racing synthetic oil for the transmission. It works for all twin-cam engines. The model starts from 1999 to date. So, you will get a wide range of options for using this oil. It protects the transmission in the best way.

It is able to deliver superior performance that is essential to protect thermal breakdown and oil deposits. If you are going to long use of your transmission, then this oil is for you. Your bike transmission won’t get too hot because this oil got the best formula to keep it cool. It also works as suitable multi-compartment oil.

This is for the v-twin engines of Harley models. This synthetic oil is engineered in such ways. It works smoothly from 4th gear to 6th gear. In every kind of temperature, this oil is the best solution to keep your transmission functional. This activity helps to extend the transmission life.

  • Suitable for every condition
  • Great formulation
  • Extend transmission life
  • Works on 4th, 5th and 6th gear
  • Cooling ability
  • It is expensive transmission oil.

Available On Amazon

3. Life Guard Fluid 8 (7 Liter)

If you are a long time user of transmission oil, then you might across different types of the brand of this product. ZF is one of those that become popular for its transmission oil. Not only that, but this well-known brand is also popular for making transmission of different types of cars and manufacture. Making complex auto transmission is not the last thing for them. They also offer transmission fluid for the gear.

If you use this fluid, then you will know why this is the best offering so far. It is formulated to use ZF transmission. But the good news is you can use it for your Harley Davidson bike. If your bike has a 6 speed great then this oil gives you the best performance so far. To extend the life of bike transmission it is formulated to boost the performance, especially for the 6-speed transmission.

Most of the transmission oil formulated for performing at a certain temperature, but this one is not. it offers consistent performance in every kind of weather condition. It can increase the efficiency of your Harley 6 speed transmission with its high-quality formula.

  • Affordable price
  • High Quality
  • Ensure better transmission life
  • Improves fuel economy
  • Works in every condition
  • Not easy to replace

Available On Amazon

4. RAVENOL J1D2113 ATF (Automatic Transmission Fluid) – 8 HP 8-Speed & 6-Speed ZF Transmissions (1 Liter)

This is another great example of the best quality transmission oil. It comes from a well-known brand called RAVENOL. This transmission oil offers the performance that you need for your transmission of Harley Davidson. This performance level of this transmission oil stands out from the other competitive transmission oil.

In overall value, this is the great choice for the owner of Harley. It is formulated to be functional for both 6 speed and 8-speed transmission. If you want to use transmission oil not only for the Harley but also for other vehicles then this oil is for you. It offers to use it on Audi, Acura, BMW, Land Rover, Honda, and many more.

It can reduce the wear in your transmission tremendously. Even it prevents overheat because of a high viscosity index. It is also offering controlled friction properties. Like other best transmission oil this one also able to perform in different weather conditions.

To offer better service it can prevent foam formation. It can keep the transmission cool because of the incredible cooling capacity.

  • Works on different weather
  • Great performance
  • Cooling capacity
  • Reduce wear
  • Better for transmission life
  • To suitable for 4th or 5th gear

Available On Amazon

5. Red Line (42804) V-Twin Transmission Car Gear Oil

This transmission oil is engineered for different types of bikes. But using it on the four-stroke and ATVs sports bike will give and Harley will give you the best result. The gearbox makes a sound because of the use of different oil. This oil can minimize this sound and offer comfort to the bike rider.

This oil has friction modifiers. To reduce the gearbox noise, this feature helps a lot. It also minimizes the noise from shifting gears. The thicker oil film plays a vital role to perform this activity. Shifting gear for your Harley is important because it tremendously affects the bike acceleration.

This oil performs effortlessly to shift the gear. To offer a layer of protection over the great teeth, this oil has viscosity characteristics. This characteristic ensures the thickness of the oil.  Without changing for a long time, this oil is able to offer efficient service. To prevent overheating this oil works well.

  • Shifting of gear becomes easy
  • Optimal performance
  • Prevent wear and tear of great teeth
  • Reduce temperature
  • The user has the issue with the color

Available On Amazon

Buying Transmission Oil For Harley 6 Speed:

If you don’t know what you need to look for buying the best transmission oil for Harley 6 speed, then it could be a stressful job for you. You cannot compromise with the wrong buying decision for transmission oil. We made our journey by researching on transmission oil for Harley Davidson.

Maybe there are lots of questions in your mind about it. Before you make the final decision for the buying transmission oil you should go through all the considerations that need to check.


This feature ensures the oil flows Viscosity defines how fast or slow the transmission oil flows. When the oil viscosity is low, then it will flow freely and fast. On the other hand, high viscosity offers fast flow. It will flow like molasses.

Transmission oil comes with a number that represents its rating. If you see 10W-30 that means it will work in a cold and hot situation. 10w is the working condition when the engine is cold and 30 is for the hot condition. Remember, buying the transmission oil of wrong viscosity can damage your engine.


Additives are another important factor that improves overall motorcycle functions. This is one of the most common and useful factors. It is true that different motorcycle transmission oil offers different additives. That means it has the ability to remove debris and acid.

This method is essential to keep the engine clean. Even it helps to increase the performance of lubrication. Additives also work on your engine to keep it cool.

Oil Grade:

You must need to pay attention to get the best and suitable grade of transmission oil. But the question is how are you going to find the actual grade? Look at the oil body and you will find a bold “W” that is written beside the company name.

Before this “W” you will find some numbers like 20W50 or 10W40.  20 is the lowest temperature and 50 are the highest. Between these temperatures this oil suit most.


You cannot overlook the price of transmission oil. According to quality and brand, the price of transmission oil varies.

Most of the time, people want to buy a cheap product. But it is not suitable at all. There is lots of high-quality transmission oil out there which is pricy.

Expensive oil can give you the best support. So, don’t hesitate to spend to keep the engine of Harley healthy.


Buying the wrong oil for your motorcycle can make you suffer a lot. Don’t choose the wrong type. If your engine accepts mineral, but you are using the synthetic then the engine starts to leak.

Choosing the right oil is important. Find out the actual requirement of your motorcycle. Buying the wrong oil means wasting money and time. So, don’t damage your motorcycle engine buying the wrong type of transmission oil.


Question 1: Which one is better,  synthetic oil or standard oil?

Answer: It is a bit confused about the standard oil and synthetic oil. It is true that standard oil is not better than synthetic oil. You don’t need to change the oil frequently if you use synthetic oil. Standard oil needs to change after a few miles. But you can enjoy your ride with synthetic oil for thousands of miles.

This oil can reduce the noise, but standard oil cannot do this in a good manner. Synthetic oil works on every type of weather condition. Standard oil Harley works on cold weather.

Question 2: Are there times that I should not use synthetic transmission oil?

Answer: There is no binding or restriction for using synthetic oil in the transmission of Harley Davidson. You can easily use it at any time as you want. The basic purpose of using this oil ensures the optimal performance of the engine.

It can extend the transmission life tremendously. This oil comes as highly slippery oil for the transmission. This character is much essential for most of the part of the bike engine. So, you can easily use this oil without any confusion at any time.

Question: 3: Can synthetic oil be considered as multifunctional?

Answer: Many bike owners use oil for any purpose. But synthetic oil perfect to use in a different product. Synthetic oil is multifunctional oil. To get the best performance, synthetic oil is best to use.

You can use it on the bike chain, clutch, and engine as well. It is able to protect the braking and gear system of the bike. It can reduce the noise of shifting gears after applying on the teeth. This oil can keep your bike engine healthy and clean all the time.