Harley 103 Transmission Oil Change: How To Change Fluid in Harley

Performing a Harley 103 transmission oil change is not as easy as some people may think.

You’ll need to do your research regarding what fluid to use, considering how many there are on the market, and also how to use it.

This article explains everything you need to know from how transmission oil works, what can be found in its composition, as well as specifics regarding the 103 Harley Davidson model.

We’ve also included some short guides here on what tools you’d need for this process and how to do it step by step. Enjoy your read!

What is Transmission Oil?

Transmission oil, also known as transmission fluid, is a substance that vehicles require to function properly.

Its purpose is to lubricate the parts inside the transmission box, thus keeping them from eroding or grinding down.

This fluid should be present for both manual and automatic gearboxes, considering that for the latter it also ensures hydraulic pressure.

Without this pressure, the internal parts wouldn’t work properly. The properties of transmission oil keep the transmission system cool as well.

It is used for vehicles since the 1940s and, today, you can choose from a variety of types with many functions other than lubrication alone.

What does it mean by 103 for Harley Davidson?

The 103 is a classic Harley Davidson twin cam engine used on motorcycles.

After the Evolution engine met great success in the industry, the company decided to move forward and create an even more impressive product, and thus invented the 103, part of the series of engines that use two cams for the valvetrain.

Its predecessors, 88 and 96 were well-received, but the 103 came with an automatic compression release system that took over, offering greater performance.

The engine is also equipped with an oil cooler, helping all Touring models reach their maximum potential.

The whole 2012 range of Harley Softail and Touring models are equipped with the 103 cubic inch engine, so it’s quite popular too.

That’s why people are heavily interested in finding Harley 103 transmission oil change tips and tutorials.

  • Features of 103 HD engines
  • Launched in 2012 after meeting success with earlier models
  • Standard equipment on the entire Softail and Touring HD motorcycles (sometimes Dyna too)
  • Rubber-mounted on the frame
  • Torque: 100 ft. lbs/3500 RPM
  • ESPFI included
  • 6-speed Cruise Drive transmission system
  • Automatic compression release
  • Air cleaner ring and oil cooler
  • Lighter weight piston design
  • Strong driveline with low routine maintenance

What is the Best Harley 103 Transmission Oil?

It’s important to figure out your vehicle’s needs and your maintenance preferences before making a purchase.

For instance, some prefer buying transmission oil types that are dedicated to certain engine types.

Others prefer to save money and buy multi-use lubricants that are not specially designed for Harley 103 or a specific engine.

Regardless of your choice, there are top-notch products on the market that will keep your shifts smooth and the transmission as quiet as possible.

Both OEM fluids and alternatives are safe to use. For Harley 103, pay careful attention to the specifications of the products used.

They need to match the engine’s needs in order to avoid voiding the motorcycle’s warranty or causing unwanted damage. 

How do you know which Transmission Oil is the best?

There are a few factors you need to take into account when picking the transmission oil.

Based on these factors, you’ll know whether the fluid is working well for your vehicle or not.

In the Harley 103 transmission oil change process, you would have to pay attention to the fluid’s lubrication capacities, its formula, as well as specific characteristics such as heat resistance or wear protection.

The overall performance level of the fluid might be influenced by its base type or viscosity indices.

Some producers add seal conditioners or other additives that bring better features to the table, offering Harley 103 users a wide selection to choose from. 

Cost of 103 Transmission Oil

There are a few costs involved for a Harley 103 transmission oil change.

Besides the product itself, you will have to consider whether you will change the fluid yourself or opt for the services of a mechanic or dealership shop.

Of course, if you want to do it yourself, you’ll need to go through all the required steps and perhaps buy some tools that are involved in the process.

With a mechanic, expect the costs to go up to $150, while in a dealership, the price might reach even $250.


The easiest and cheapest method is to learn how to do it yourself. If that’s the case, you’ll only need some tools and a transmission fluid of your choice.

This would cost around $50 total. Continue reading to learn more about the process.

Tools Required for a Transmission Oil Change

Here are some tools that you’ll need to perform the Harley 103 transmission oil change yourself. You might already have some of these at home, so you won’t need to buy every single one of them. You’ll only need:

  • Screwdrivers, long-necked funnel, Allen keys, torque wrench
  • A recipient for collecting the old fluid
  • A funnel to easily pour the fluid
  • Cloths for cleaning the parts
  • Gloves to avoid getting skin in contact with the fluids

Steps to Follow For Harley 103 Transmission Oil Change

The process itself is pretty easy to do, so don’t worry about jumping into it yourself, without the help of a mechanic. Here’s what you need to do step by step:

  • Step 1: Warm up the bike. As the oil becomes warm, you can start the draining out process.
  • Step 2: Park the motorcycle and set it in place with a center stand.
  • Step 3: Locate the drain plug. It should be near the shock absorbers of your bike.
  • Step 4: Place a recipient underneath this plug for drainage.
  • Step 5: Remove the drain plug. Usually, for Harley models you’ll have to use an 8mm Allen key, but it may vary.
  • Step 6: Clean the drain plug while the recipient fills with used fluid.
  • Step 7: Once all the fluid was drained, you can start adding the new transmission oil using a funnel.
  • Step 8: Clean any traces of excess fluid, place the drain plug back and you’re good to go.

Make sure to keep an eye on the motorcycle’s performance in the next few days. Always check if there’s any leakage and closely follow the transmission oil level.

How is the engine improved after changing the transmission oil?

Many people are not even aware that transmission oil needs to be changed now and then. This is actually an essential step in keeping your engine at peak performance.

If the transmission is working properly, you’ll start experiencing a better fuel consumption level.

The transmission will start running smoothly with fresh fluid, thus making the engine run smoother as well.

You will no longer experience engine lock-up with your motorcycle as long as the transmission works properly.

Consequently, you will save a lot of money through fuel consumption reduction and by avoiding further engine or transmission problems.

Transmission oil changing tips

It would be advised to research your options before engaging in Harley 103 transmission oil change.

If you’re not on top of your game when it comes to motorcycle components or you’re not confident in your mechanical skills, it would be best to leave it in the hands of a professional.

Available 103 transmission oil for Harley bikes

01. Oil Change Kit for Twin-Cam Harley Davidson from Maxima Hiflofiltro


Highlighted features

  • Complete kit for engine and transmission oil change
  • 3 types of V-Twin fluids included
  • Synthetic-, mineral- and petroleum-based formulas
  • Comes with included filters

This oil change kit from Maxima Hiflofiltro is one of the most complete ones you’ll find on the market.

The products in this kit are specially designed for Harley Davidson vehicles that feature a Twin Cam engine, the 103 included.

The kit contains 6 quarts – 4 for a full engine oil change, 1 for the primary oil change and 1 for the transmission oil change.

Plus, it also comes with a filter included. It’s quite a complete package and a much better deal than buying transmission fluid on its own.

Of course, you’d have to follow clear Harley Davidson transmission oil change instructions, but once you have these quality products, it shouldn’t be an issue.


  • Complete set for a whole fluid change
  • Contains everything needed for the process


  • Sometimes, specific parts can miss from the kit

02. Red Line V-Twin Transmission Oil

Highlighted features

  • Ensures a very smooth shifting in V-Twin transmissions
  • Improves performance by reducing temperature and ensuring oil films
  • Perfect for motorcycles and four-stroke ATVs or other types of sportbikes
  • Known for dampening transmission noise

Red Line is known for producing high-quality fluids, and there’s no surprise that this V-Twin transmission oil is recommended for the Harley Davidson range.

This product brings forth a few aspects that make it stand out from the crowd.

First of all, it’s popular for increasing transmission performance thanks to its temperature reducing properties, as well as the thick oil films it leaves behind between the gear teeth.

It makes throw-off resistance much better, and you’ll be able to feel that in the shift change smoothness.

Second of all, it’s one of the most applauded transmission fluids in terms of noise reduction.

Most people who used this oil noticed a visible decrease in the noise produced by their transmission. It’s definitely worth giving a shot!


  • Impressive results, similar to OEM products
  • Neutral becomes much easier to find after usage


  • The product’s odor is quite strong

FAQ’s Harley Davidson Transmission Oil Change Instructions

How much oil does a Harley 103 transmission change involve?

You would need 1 quart for a full transmission oil change. Usually, you’ll find these in packages that include engine oil as well.

How often should you do a Harley 103 transmission oil change?

You’ll have to read your motorcycle’s owner’s manual to know for sure when it’s recommended to change the transmission oil.

On a general basis, this period is measured in miles. Take into account how long you’re on the roads and adapt the average distance to your maintenance requirements.

The transmission requires changing the fluid every 5-10K miles. The same goes for primary oil changes.

Keep in mind that this might also depend on the type of transmission oil that you’re selecting.

Mineral-based oils require a 2K miles change, whereas synthetic lasts longer, allowing for a 5K-10K miles change.

What oil should you use for a Harley 103 transmission?

There are many types on the market, but it would be recommended to opt for a full synthetic transmission oil.

This one is the longest lasting – you will have to change the oil less often than in the case of mineral-based products or partly synthetic ones.

Of course, it remains up to you and it heavily depends on what characteristics your motorcycle has.

How do you check the transmission oil level on a Harley Davidson?

After warming up your motorcycle, you can check the transmission oil level with the help of a dipstick.

The warm-up step can’t be skipped, because the oil levels are only relevant when the fluid reached its top operating temperature.

That’s the correct consistency to check. Once that’s done, place your motorcycle on a level surface, get the dipstick out, wipe it off and place it back in with the O ring touching the case.

Remove the dipstick and check whether the oil level is somewhere between Add and Full.


We hope that you found this article helpful and informative, as we tried to cover everything related to the Harley 103 transmission oil change process.

You should have enough information to do it yourself and make a wise decision regarding the product you’ll use.

Take your time to read as much as possible about the topic before engaging into the process itself.