Top 5 Best Oil For Harley Transmission In 2023 | Top Ranking

Oils play one of the most important roles in our Harley bikes. Not only does the right oil ensure proper gear control & lubrication, it also helps to keep all the components at their best shape. That is why getting the best oil for Harley Transmission is a must. 

But unfortunately, many of us do not know much about these harley transmission oils. As there are so many options available in the market, it is really hard to choose the very best one.

Luckily, you are in the right place. We have put our years of riding experience to find the top 10 oils for you. You will get an in-depth review, their toe to toe comparison, pros-cons & many more.  

Let’s Ride Along!

Here’s a comparison table to give you a brief idea about all the products. Check it out then read the in detail reviews to know everything about them.

NameSpecial FeaturesSizePrice
1. Spectro Oil R.HDPG6 Heavy Duty Platinum Full Synthetic 6spd Trans Lube1. Cures transmission noise.2.Smooth shifting.3. G4 Technology32 Fluid OuncesHigh
2. Red Line 90226 Big Twin 20w50 PowerPack Oil Package1. Shockproof technology2. Offers complete synthetic package3. Works better in hotter climates256 Fluid OuncesHigh
3. Mobil (112812-4PK) Delvac Synthetic Transmission Fluid 50 – 1 Gallon1. Provide one of the best protection2. Synthetic oil3. Gives stronger film strength 128 Fluid OuncesVery High
4. Red Line RED42804 V-Twin Transmission Oil1. Reduces temperature.2. Shockproof Technology3. Dampens transmission noise1 Quart(1 Pack)Medium
5. Valvoline VR1 Racing SAE 20W-501. Race level protection2.Maximizes horsepower3.High Zinc & Phosphorus formula5 QuartsHigh
6. Maxima Racing Oils 40-01901 85w140 V-Twin Transmission/Gear Oil1. Mineral based oil2. Usable in 4-, 5- and 6-speed high performance gear boxes3. High film strength gear oil32 Fluid OuncesMedium
7. Red Line 42804 V-Twin Transmission Oil1. Shockproof technology2. Perfect for high revving four-stroke motocross bikes3. Dampens transmission noise1 Quart(1 Pack)High
8. Lucas Oil Synthetic SAE 75W-140 V-T1. Easier & smoother shifting.2. Clear & slick. 32 Fluid OuncesLow
9. Life Guard Fluid 8 (7 Liter)1. New product2.Similar to Mopar 8&9 speed ATF liquid7 LiterHigh
10. MaximaHiflofiltro VTTOCK14 Complete Engine Oil Change Kit1. Full Synthetic2.Complete Engine oil change kit3. Offers 28% longer life.192 Fluid OuncesMedium

Top 10 Best Oil For Harley Transmission

Considering each & every angle, these 10 made it to the list. Hope these harley davidson transmission oils will be a perfect match for you and you’ll be able to clear your confusion permanently.

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

We used this spectro oil personally. And trust me it was totally up to the expectation for a regular long-distance rider like us. 

It is especially made to cure noisy six speed harley transmissions. So anyone is suffering from any kind of annoying noise on their long-distance rides, they can try out this one.

The spectro have made this oil specially suitable for high temperature. It is absolutely perfect for the engines when you go out for a long ride under high heat.

It eliminates clunks & ensures smoother shifting as well. The Spectro Oil R.HDPG6 has extra additives & G4 technology in it. So it provides extra strength between the gears & while extending gear life reduces drag.

Another plus point is that this oil ensures anti-wear protection & reduces the fifth-gear whine as well. 
It is also A.P.I. GL-5 rated. It also meets the Harley Davidson warranty requirements. So even if it is pushed hard & long, it will work perfectly.

  • Perfectly suitable for long-distance rides.
  • Solves noisy 6 speed harley transmission problems.
  • G4 technology is available.
  • Works properly in high temperatures.
  • Increases the overall efficiency.
  • Comparatively costlier.


Absolute perfect for long distance rides. It will keep efficiency in the engine components. Also if you are having noise or heat problems in the engine, we recommend using this oil. The cost is absolutely worth it.

2. Red Line 90226 Big Twin 20w50 PowerPack Oil Package

Next up, we have a Redline Harley Transmission oil. This oil package has everything you need for any kind of harley transmission oil change. You can easily change the oil all by yourself at one go.

It comes as a powerpack & is perfect for any hardcore bikers. It makes sure that the engine is effective & efficient. 

Thinking of using it in high temperatures? Nothing to worry about. Rather, it works better in hotter climates. No matter what the temperature is, the viscosity remains good.

The 5 quarts of 20W50 Motorcycle Oil comes with a variety of stuff. The package includes 1 bottle of Fuel Injection Cleaner, 1 quart of V-Twin Transmission Oil with ShockProof and 1 quart of Primary Chain Case Oil. 

It also includes a versatile funnel as well.

What else? The 20W50 motor oil comes with good anti-wear as it has a high level of zinc & Phosphorus. So this synthetic oil is perfect for sport bikes & V-twin motorcycles.

  • Good for a complete new Harley Transmission Fluid Change.
  • Can work perfectly in hotter climates.
  • Comes as a perfect package.
  • It is economical.
  • Some people had problems with the packaging.


The RedLine 90226 Big Twin 20w50 oil comes as a perfect package. You can definitely go for this economical, effective & efficient oil.

3. Mobil (112812-4PK) Delvac Synthetic Transmission Fluid 50 – 1 Gallon

This Mobil Delvac Transmission Oil is gaining popularity day by day with all its exciting features.

It provides maximum protection & extends the operating life to any kind of heavy duty transmissions. It offers good lubrication as well. 

This synthetic oil has many advantages over the usual conventional gear oils with sulfur & phosphorus. One of our members has been using this for a very long time. The reason is he has got a good anti-wear & EP performance. 

It protects you from different kinds of deposit formation & corrosion of copper. 

Not only that, the oil is totally optimized with thermal & oxidation protection.

So as for the protection issues, you have nothing to worry about.

At higher temperatures, this oil gives stronger film strength compared to the conventional oils. 

Another plus point is that, when you ride at below freezing temperatures, it ensures proper lubrication. The shear stability is also pretty much good.

  • Better than conventional oils.
  • Good protection.
  • Proper lubrication.
  • Excellent load carrying.
  • Costly.


The oil gives excellent protection & offers good lubrication. It is perfect for heavy duty transmissions.

4. Red Line RED42804 V-Twin Transmission Oil

This Red Line is one of our most favorite & most used oils. 

Let me ask first, who likes transmission noise? No one does. This Red Line Transmission oil especially reduces the transmission noise & saves us from that trouble.

The formula that helps to dramatically reduce the temperature. Between the gear teeth, it helps to provide thicker oil films. Thus, the efficiency is improved in every manner.

It is mainly engineered & manufactured for the ATVs Sportbikes & the four-stroke motocross bikes. So for a lot of Harley bikes, it is absolutely perfect.

The oil ensures good shifting of gear. Also we liked another thing. The pink color is really easy to notice & helps to identify any kind of leakage.

Hang in there! It has two more functions which makes it really special.

One is that it has shockproof technology used in it like other Red Line oils. Another is that the oil reduces the notorious shifting clunk. 

So not just the noise issue is fixed, but also the overall performance of the engine is highly increased.

  • Good for high revving four-stroke motocross & ATVs bikes.
  • Reduces temperature.
  • Fixes transmission noise.
  • The pink color is easy to identify.
  • Some people might not like the pink color.


We love this oil,that’s it! It fixed the noise issue in one of our member’s bikes. It is overall a good option for four-stroke motocross bikes. Also the price is quite in range as well.

5. Valvoline VR1 Racing SAE 20W-50

If you have a high-performance vehicle & look for protection, then close your eyes, choose this oil.

This Valvoline oil offers a high level of protection in every manner for our engines. It is formulated in such a way that it offers race-level protection for high-performance bikes.

The specialized formula provides anti-wear protection & temperature protection. 

The quality of the oil is so good that it helps to enhance the overall horsepower of the engine. Moreover it increases the lifespan as well. 

There is another thing we liked about this oil. It has different detergents & antioxidants in it. So helps in reducing the friction & keeps the engine really clean. It is definitely one of the best lubricants as well.

So for both passenger vehicle engines & race engines, you can easily use this oil.

  • Provides one of the best levels of protection.
  • Increases the lifespan of the engine.
  • Keeps the engine clean.
  • Well formulated for race engines.
  • They’ve increased the price. However it is still budget friendly.


Good for overall protection & increasement of lifespan of the engine.

6. Maxima Racing Oils 40-01901 85w140 V-Twin Transmission/Gear Oil

This Maxima oil is a mineral based motorcycle gear oil which you can use in 4-, 5- & 6- speed high performance gear boxes. It is good in high temperatures and enhances the overall performance of Harley bikes. 

 One of my friends had issues with viscosity loss. But when he used this oil I heard he got excellent protection in return.

The formula has different kinds of extreme additives that allow proper shifting even under peak loads for our Harleys.

It is also good against shock loads & wear. As the oil is mineral based, it’s pretty light.

Not only special additives, the Mamima racing oil uses ultra-clean detergents. So protection from different wear & deposits is ensured.

  • Lightweight
  • Enhances the overall performance
  • Good protection
  • Special additives & detergents.
  • Trouble free operation.
  • Some people do not like the design.


Has a lot of offerings like solutions to viscosity loss, good protections from wear & temperature etc. The cost is good as well.

7. Red Line 42804 V-Twin Transmission Oil

Next up, we have another Red Line product which makes it to the list of best oil for Harley Transmission. Just like we said it earlier, this product will also solve your noise problem. It will surely dampen the transmission noise. 

Just like some other RedLine Oils, it ensures reducing the temperature. It is one of the best features I like about it. Not all oils can do that.

This Harley transmission oil weight is around 4.24 pounds. 

Heard of Heavy Shockproof gear oil? It has the same fluid as that one.

You can use it especially for four-stroke bikes & V-Twins. It will also go perfectly for your ATVs & sport bikes as they are specially engineered like that.

The Red Line product is made of special anti-wear chemistry like Zinc & Phosphorus. So a good level of protection is guaranteed as well. 

The formula ensures good lifespan & efficiency.

  • Reduces the temperature (Best feature for me).
  • Usable in four-stroke bikes, V-Twins, ATVs & sport bikes.
  • Good overall protection.
  • Enhances lifespan & efficiency.
  • Not all people like the color pink.


We love Red Line products. But without showing any kind of partiality, we assure you it’s good for your Harley vehicle.

8. Lucas Oil Synthetic SAE 75W-140 V-T

Let me start by sharing a story.

One of our members changed all three oils in the Harley Wide glide. He then shifted to this Lucas synthetic oil. And we got to see his bike work better and unexpectedly became a bit quieter.

It is synthetic & goes well for our Harley bikes. Increases the comfort & overall functionality of the engines. 

This might not be the most popular oil but hey it does the job. Many people are confused that it is red. Actually no, it is a bit light brown.  

The product has improved the performance of our Harley Davidson motorcycles. We have seen a big positive difference in Softail transmissions.  It is very clear & slick. 

The formula makes the shifting easier, smoother & quieter. So if you are having troubles with shifting, try out this oil.

  • Good for shifting.
  • Clear & slick.
  • Increases comfort & functionality.
  • Low cost.
  • Some people faced packaging problems.


According to us, it’s really good for shifting. Comes at a low price so you can use it to increase the functionality of your engine.

9. Life Guard Fluid 8 (7 Liter)

In our next listing, we have a brand new product. 

It comes with a total of 7 Liter and costs less than 140 bucks. According to our in depth research, it is similar to Mopar 8&9 speed ATF liquid.

Although it is a new product, it has created quite a bit of popularity for itself in the market. Its total item weight is around a whooping 14.62 pounds.The oil helps between the gears as well. 

Most of the time, we might just need 4 or 5 quarts. But hey, 7 liters is more than enough & we can always keep the extras to ourselves.

 Many people are trying it out these days & they are thinking of using it for the long term.

  • Too much quantity.
  • New product, but gaining popularity day by day.
  • Helps in the gears.
  • The smell is acrid.


This one is the only new product we are suggesting as it has a lot of potential. You can also try it out, who knows this might be your long term solution.

10. MaximaHiflofiltro VTTOCK14 Complete Engine Oil Change Kit

Our last suggestion is this MaximaHiflofiltro oil. For Harley Davidson oil change, it is a perfect product from many angles. 

Many of our members use the Twin Cam motorcycles. And they have used this oil. It fits all Twin Cam Harley Davidson motorcycles. 

With the 4 Quarts of Maxima V-Twin Full Synthetic 20w50 Engine Oil a lot of things come in the package. There is transmission oil & premium oil filter as well.

Not only does this synthetic oil lower the temperature but it also reduces the wear. It is a mineral based gear oil which helps to increase the film strength.

All of us who use Harleys want good protection. It is one kind of a must. And this oil provides extended protection along with high performance transmissions.

The formula is made from high quality materials. In fact it is proved that they offer 28% longer service life than their competitors. 

It has a system of regenerative polymers that resists heat breakdown & mechanical shearing. Performs excellently with the additives used in it against different climates. 

Last but not the least, it also has additives that keeps the engine super clean. Protection against sludge, gear, deposits, wear is ensured & a complete trouble free operation is ensured.

  • Good overall package.
  • Good protection.
  • Cleans the engine.
  • Resists heat breakdown & mechanical shearing.
  • Good for oil change.
  • Fits perfectly in all Twin Cam Harley Davidson motorcycles
  • Some people have faced packaging related problems.


One of the best oils out there. Offers almost everything at a good price.

Things to Consider Before Buying

We have put both our expertise & experience in getting these top 10 products for you. Out of the hundreds, these seemed the very best ones among us. However, before finally buying it, these are the things you should consider:

  1. Viscosity

Not just for Harley bikes, for any motorcycles or cars or trucks, viscosity is a very big thing.. You should know about your bike’s viscosity level perfectly. 

You will get everything you need to know about it in the owner’s manual. However there are some basic things every Harley owner should at least know.

Viscosity simply means the speed of the flow of the oil. The higher the viscosity, the faster the oil flows. In case of lower viscosity level, it is the exact opposite.

So, know you bike, check the viscosity level, choose the oil accordingly.

2. Type

This is another thing. You should know what type of oil is suitable for your Harley bikes.

There are mainly three types of oil. 

  • Mineral based oils: There have been questions about the stability of these oils. Also they might not be the best for our bikes.
  • Semi-Synthetic: These oils cost a bit less comparatively. They are a mixed version of crude oil & synthetic components.
  • Full-Synthetic: These are the best ones. They are highly compatible for the Harley Davidson bikes. In Fact these are the most common Harley Davidson fluid types. 

Most of the enlisted products in this guide are full-synthetic oils. We suggest you get the same. It might be a bit costly, but surely gets the job done. 

However, you should definitely check the owners manual or contact with your manufacturer to be sure what type of oil you need.

3. Quality

Always, I mean always check the quality of the oil.

You have spent a lot on your Harley Davidson vehicle, So why would you compromise on the Harley Transmission oil quality

We have identified the best oils with the highest caliber for you. Even if you have a budget issue, you can definitely get the best oil under that budget as well. 

So don’t use any kind of oil, use the best ones.

4. Longevity 

Here’s another thing which many people don’t consider before making the final call. Longevity of the product must be noticed in every circumstance. We can take a ride in any kind of weather. So the product’s longevity has to be noted.

5. Price

Many people can give suggestions about their own personal favorite oils. But hey, you know about your budget. 

So choose the best budget friendly option available for you. But our suggestion would be do not take the cheapest one. Spend a bit(which is of course affordable for you) & get the best possible one.

6. Additives & Detergents

Check the formula & identify the additives & detergents. How much protection can the additives provide? How clean will this oil make the engine? Consider these things before buying the oil.

You need protection from wear, deposits, high temperature etc. And the oil should contain different additives & detergents for this. Considering these things is a must.

7. Reviews & Recommendation

One more thing you should consider is the reviews. 

People have used that oil before you. So they have some sort of experience. Try to check or research a bit about it on your own. 

Check the average rating on the reviews. Check why people are recommending it. Then buy accordingly.

We hope if you consider these things before buying, you can definitely get the best oil for Harley Transmission.

Best Oil For Harley Transmission

Frequently Asked Questions (FAQ)

1. Is primary fluid and transmission fluid the same?

Answer: No, there are some differences between Primary Fluid & Transmission Fluid.

Most of the time transmission fluids have higher viscosity. You know what that means right? It’s the flow of oil speed.

 So transmission fluids often help in reducing the transmission gear noise and also helps to enable easy shifting.

On the other hand, most of the primary fluids are much thicker. It focuses on offering better stability. 

2. How often should you change the oil on a Harley?

Answer: Well, it depends on how much you ride & the type of oil you use.

If you use semi-synthetic oil, then you should change the oil after riding 5000 to 8000 miles. But if you use synthetic oil like us, you should change your oil after 7000 to 10000 miles. 

3. Can I use engine oil in transmission?

Answer: No, it is better not to.

If you use engine oil in transmission then there will be poor lubrication.

Also if you use it you might face overheating issues as well. In fact, some people have faced entire transmission failures because of using it. So it is better not to use it.

4. What happens if you put gear oil in transmission?

Answer: It depends on the transmission you are using. While most transmissions use gear oils, some don’t. 

So if your transmission uses gear oil, then you have nothing to worry about. Use the best gear oil in perfect quantity.

But if the transmission is not suitable to gear oil, then you are making a big mistake. It might work for a while but it will damage the engine sooner or later.

5. How much oil does a Harley transmission hold?

Answer: The transmission fluid capacity is around 0.7 liters. Which is around 24 ounces.

6. Can I use 75w90 in my Harley transmission?

Answer: 75w90 is a synthetic gear oil, so it’s gonna be okay if you use it.

7. What oil goes in a Harley transmission?

Answer: AMSOIL recommends that the 20w-50 synthetic V-twin motorcycle oil goes perfectly for transmission, engine & primary chaincase for most of the engines.

8. What kind of oil goes in Harley primary?

Answer: We suggest you use Mobil 1 Racing™ 4T 10W-40, you can also use the Mobil 1™ V-Twin 20W-50 oil as well. It goes & works perfectly in the Harley primary.

9. What oil does Harley Davidson recommend?

Answer: Harley Davidson recommends using SAE 20W50 synthetic oils. It is suitable for all kinds of climates. 

But our suggestion would be if you live in a cold area, such as an area that has a temperature of below 5°C, you should go for SAE 10W40 oils. They are going to be better for you.

10. How to check transmission fluid Harley Davidson?

Answer: Go through the following easy & simple steps to check transmission fluid Harley Davison:

  • Put the bike on the side stand. 
  • Warm up the engine a bit. Shift it through all gears & turn it off when you think it’s sufficiently warm enough.
  • Unscrew the transmission dipstick & loose it up a bit. Many people accidently remove it, but make sure you do not do that.
  • The next step is to straddle the Harley off the side stand. For around 20 to 30 seconds try to hold it level.
  • Now the transmission dipstick must be removed and cleaned.
  • Insert the dipstick. Do it until the top of the threads rests on top of the hole. 
  • To get the amount of fluid in the transmission, withdraw the dipstick & read it.
  • Put the dipstick back in the engine & start the engine. Shift through all of the gears & then turn it off. Let it stand for around 30 seconds. 
  • Repeat the rest of step 3 & read all the levels. 
  • Keep it up & you will get the perfect amount of fluid. 

Final Thought

Hope you have found your way to get the best oil for Harley Transmission. 

Before getting the oil, read the buyers guide, special features, pros & cons carefully. Also to clear your doubt you can try two or three best ones consecutively. Then you can make your long term decision.

We assure you, our experience & expertise won’t disappoint you. So hope you have your confusions cleared & will get the perfect oil for your Harley Bike.

Till then, enjoy your ride!

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