In the Hollywood movie, George said “This? This is Harley Davidson. It is the best damn motorcycle ever made”, we really couldn’t agree more. If you want such an asset but are confused about the right transmission oil for it, then we are here to discuss the best options from the current day market.
As a motorbike lover, you can take pride in having a Harley Davidson product. But from my personal experience, I can say that you have to be extra cautious in taking care of such a masterpiece. That is why we have prepared this list of the best transmission oils for Harley 6 Speed.
Transmission oil is not used to lubricate only the moving parts of the vehicle but also helps the internal parts. Along with protecting metal surfaces from wear and providing assistance in controlling the temperature it also ensures better fuel economy. Thus you have to be extra choosy in selecting the right oil.
Top 5 Best Transmission Oil For Harley 6 Speed Reviews
1. Spectro Oil R.HDPG6 Heavy Duty Synthetic Oil
When you want a quiet journey for your long road trip, Spectro should be your obvious first choice. When Harley Davidson owners complained about the great but noisy speed transmission, they manufactured this fully synthetic oil to provide ultimate lubrication protection.
This transmission oil has been formulated to significantly reduce gear noise and provide smoother and easier shifting. By reducing fifth-gear whining and eliminating clunks, this oil cures noisy six-speed transmissions. The primary reason that owners of Harley six-speeds praise this transmission oil is the smoother and quieter shifting.
This SAE 75W140 formulation eases shifting even when cold. High loads and extreme heat also cannot affect the oil and its performance. Thus the performance is not compromised even when pushed hard and long.
Apart from all these features, another fact the users found astonishing is, that even as a new transmission, the oil doesn’t cause any metals on the plug magnet or signs of wear on the fluid itself. The oil quits down 5th gear and is easy to find neutral. The oil is a universal fit and you can put more than 5000 miles on it.
- A.P.I GL-5 rated.
- Use of G4 technology.
- Dyed red.
- Liquid volume – 32 fluid ounces.
- Special additives to provide additional anti-wear protection.
- Higher film strength between the gears.
- Reduces drag while extending gear life.
- Smoothest, quietest shifting.
- Easiest finding neutral.
- Unaffected by extreme heat.
- Reduces fifth gear whine and eliminates clunks.
2. Red Line 90226 Big Twin 20W50 Power Pack Oil
If you are looking for cooler operating temperatures, better shifting, less noise, and less wear, you can totally depend on a legendary brand like Red Line. The brand with its power pack oil can be a great choice for your Harley Davidson with its latest design and superior strength.
The complete package costs much less than the total market price of the included products. Thus this budget-friendliness of Red Line has made the product more popular in the market. Apart from the budget, another fact to love about this oil is it runs extremely well in stops and Southern heat as well as in wintry weather.
The customers love how Red Line oil makes the transmission significantly quieter and no huge clunks are found. They can very easily monitor the tranny oil level, if there is any leakage, by how simple it is to find neutral. If it starts to get really finicky, then you understand that you are low on tranny oil.
- Viscosity – 20W50.
- Liquid Volume – 256 fluid ounces.
- Synthetic oil.
- Designed for the latest big-twin motorcycle engines.
- Runs cooler and quieter.
- Superior film strength through the use of ring seal.
- Extended drain intervals over other brands.
- Higher quality base stocks and excellent dispersants.
- Blended with specific friction modifiers that are compatible with wet-clutches.
- The package contains only one quart of fluid and no O- ring.
3. Bel-Ray VTwin Primary Chinese Lubricant
The primary Chaincase lubricant from Bel-Ray is another great choice for your Harley Davidson. The oil is specially formulated for the primary chain case of big twin motorcycles.
Ideally, the product is designed and suited to stand up to high pressures. The transmission oil is formed to reduce or eliminate and compensate for the noise and chatter it to extend the life of your clutch over motor oil. It also offers improved lubrication on your clutch to prevent slipping.
The exclusive Bel-Ray anti-wear chemistry present in the oil ensures long service life for the primary chain. For extended performance, the oil is formulated with superior oxidation protection. It also prevents clutch slipping and chatter for consistent engagement.
The distinctive red color makes it easier to detect leaks in multiple lubrication cavity engines. The oil has been in the market since the 70’s and the users have always loved its extra slickness.
- Liquid volume – 1000 millilitres.
- API – GL 5 rating.
- Petroleum oil.
- Color – Red.
- Distinctive red color for easy leak detection.
- Formulated for primary chains and wet clutches.
- Wear protection for extension of primary chain life and gear protection.
- Prevents clutch slipping and chatter.
- Smoother clutch engagement and disengagement.
- Maximized horsepower.
- Out of budget for many users.
Bel-Ray Primary Chinese Lubricant Video Review
4. Red Line RED42804 V-Twin Transmission Oil
From the house of Red Line, this oil is another extremely popular choice among Americans. This revolutionary lubricant is completely different from conventional lubricant technology in many ways. And that’s why the users themselves claim that you won’t try anything else after using this oil.
This V-Twin transmission oil is formulated to reduce the notorious shifting clunk found in the gearboxes. To improve the performance of your Harley Davidson, the oil is designed to reduce temperature dramatically and provide thicker oil films between gear teeth.
By completing all the above-mentioned tasks, the oil dampens transmission noise. The company uses cutting-edge technology while formulating the oil. To match with the latest high-revving four-stroke motocross bikes, the oil is specifically engineered.
The oil is packed with higher levels of anti-wear chemistry like zinc and phosphorus special friction modifiers. This heavy shockproof gear oil provides much greater viscosity in the thin layers between the gear teeth but has very low internal fluid friction. This means very little power loss for the protection achieved.
As far as the owners of the Harley-Davidson are concerned, they have always praised this Red Line product for its capability of always finding neutral, making it quieter, and making the journey extra smooth. They loved the way his oil almost eliminated the first to second clear clunk.
- Full synthetic oil.
- Volume – 946 ml.
- Designed for high-revving four-strokes motocross bikes.
- Great extreme pressure protection.
- Reduces temperature dramatically.
- Resistes throw-off completely.
- Reduces metal-to-metal contact.
- Reduces gear noise.
- Low fluid friction to improve power transfer.
- The burnt oil coming out has a bad odor.
5. Ravenol ATF 8HP Fluid
If you want to try something new but smartly formulated oil for your Harley Davidson, the 8HP fluid from Ravenol might be an extremely great choice. The product received positive reviews from customers of all the areas in the USA.
Ravenol 8HP fluid is a synthetic automatic transmission fluid, designed on the basis of high-quality hydrocrack oils with a special additive and inhibition. This feature ensures a perfect inhibition of the automatic transmission.
Ravenol ATF 8HP is an automatic transmission oil of the latest generation for all 8-stroke automatic transmissions from the brand. Because of the amazing lubricating capability, the oil can provide a high yet stable viscosity index even at a low temperature.
Along with a great viscosity index at both cold and hot temperatures, the oil comes with great oxidation stability. If you want complete protection against corrosion and foam formation, then this oil is the right one for your bike.
To ensure smooth and efficient shifting over the fluid’s life, the oil is formulated with controlled friction properties. The oil has also been liked for its anti-wear, corrosion-resistant features along with its ability to oxidation and thermal stability.
- Synthetic oil.
- Color – Green.
- Compatible with ATF 8HP series.
- Liquid volume – 1L.
- Excellent lubricating quality even at lower temperatures in winter.
- A high, stable viscosity index.
- Great oxidation stability.
- Protection against wear, corrosion, and foam formation.
- A high thermal and oxidative stability.
- An excellent cooling capacity.
- A little bit expensive
Buying Guide for the Best Transmission Oil for Harley 6 Speed
As we have already discussed, you cannot just put any oil in a Harley-Davidson, which has been ruling the worldwide market for decades. But recognizing the Best fluids for Harley Davidson is not that easy. So here we will be discussing the buying tips for the best Harley Davidson transmission oils.
Along with vehicle compatibility, you have to take care of your budget, types of additives in the oil, viscosity index, and capability to work in both lower and higher temperatures.
As you are aware of the exact edition and model of your Harley Davidson, you must check the compatibility of the transmission fluid at first. But apart from just checking the compatibility list provided by the company, you should go through the manual from the vehicle owner.
After reading the manufacturing company’s manual you can understand the needs of your bike better. The type of liquid, the necessary composition of the oil, and sometimes the names of specific brands of transmission fluid are suggested by Harley.
Extra additives are mixed with transmission fluids in order to keep the functional properties of the oil intact. To save the transmission system from corrosion, foaming, or oxidation, companies add protective additives in the oil. Some companies also include additives to ensure better heat resistance and leak fixing.
Your job is to see if the right additives have been mixed in your preferred oil. Unlike most of the additives, a few can be harmful to both fluid and the transmission system. So, gather adequate information to choose the right fluid with the right additives.
It is one of the first responsibilities of a bike owner to check the viscosity index before buying any lubricating oil. Usually, the product’s maintenance manual mentions the viscosity grade.
But if it doesn’t, then you can determine it by following the ANSI and AGMA methods or some other ways. High-viscosity oils are great for higher loads, rough roads, and low speeds. On the other hand, low-viscosity oils are good for high-speed systems with lower loads.
Type of Oil
Synthetic and natural – these two are the two basic types of transmission fluids. Synthetic oil is the more popular, costly, and heat-resistant option. Synthetic transmission fluid also ensures better performance in extremely cold weather.
Apart from being great in both high and low temperatures, they are preferable for long-lastingness and overall performance.
Location and weather
The geographical area that you are living in, will play an important role in the performance of your transmission oil. Also, you must check the shipping update to your state and if the item is locally available, in case shipment is not available.
Not all fluids are equally compatible with extremely hot weather, neither do all of them perform well in extreme cold. Sometimes, the transmission oil can break down in excessive heat as well. So always keep in our mind the geographical facts.
Usually, it is advised to choose renowned brands for transmission oil because in this product’s case, some selected brands are really trustworthy. The products from those brands are not necessarily always out of your budget. But you should make a round budget for the total cost that you have to spend on transmission oil.
And most importantly, many new brands are coming out nowadays with smartly formulated fluids. So you can choose from any of those, but in this case, also, it is better to have an idea of your budget.
FAQs About Transmission Oil For Harley Davidson
How can I identify the lack of transmission fluid?
Any kind of burning smell coming from your bike and any kind of clunky noise during driving can indicate the shortage of fluid, because if the transmission system is working properly and there is no leak or shortage of the fluid, there shouldn’t be any noise or smell.
Apart from these, if you face any sudden jerks or slipping gears are signs of lack of transmission fluid.
How often should I change the transmission fluid for my Harley Davidson?
There are no strict rules that you must follow while changing the transmission oil for your bike. You can change it any time depending on the environment, oil quality, etc as those things determine how long you can go after filling the oil into your Harley Davidson.
Usually, the manual from the company carries such information. But somewhere between 30000-60000 miles is believed to be the perfect amount of distance that you can go without changing the fluid.
Can I change the transmission oil for my bike, all by myself?
Absolutely! You can easily change the transmission oil for your Harley-Davidson all by yourself. You just have to have some basic knowledge of bikes and some preparation with adequate time.
How to Change Harly Davidson Transmission Fluid
After going through this elaborate discussion on the use, benefits, and characteristic features of the recommended oils, your confusion most probably has come to an end. To save you from any unpleasant experience during purchasing or afterward, we have also provided the necessary buying suggestions.
So based on your budget, geography, and other choices, grab the most suitable transmission oil from our list and reviews of the best transmission oil for Harley 6 speed.