How To Check Primary Oil On Harley Davidson? [6 Easy Steps]

You can check the engine oil on your Harley Davidson bike by following a few steps, which include parking your bike, finding the primary oil check plug, and then simply opening the plug and checking the oil level.

It is crucial to check the primary oil level and replace it if necessary if you want optimal performance. If it is your first time, the process may seem really complicated, but it is quite easy and you can do it by yourself. Let’s find out the details.

How To Check Primary Oil On Harley Davidson

Once the primary oil level goes low on your Harley Davidson bike you must change it. If you do not change the oil on time it can severely damage the engine of your bike. 

Step 1: Start and run the engine

Every service center suggests that you should heat your engine before checking the oil level. Start the engine and run it for around 30 minutes and turn your bike off. 

Step 2: Park the Bike

After turning off the engine, you will need to park the bike in a flat space so the bike doesn’t roll on during the process. This will also ensure that you can read the oil level perfectly. 

Step 3: Locate the primary oil check plug

Once the bike is parked, you will need to look for the primary oil check plug. Normally, it may be found next to the foot controls on the right side of your motorcycle. 

It functions like a screw to keep the main oil from escaping. If you cannot find the plug on the right side of your bike, try looking at the user manual for the exact location, as it can vary between models. 

Read Also: Harley Davidson Twin Cam 88 Oil Capacity [An On-Point Guide!] 

Step 4: Open the plug

Open The Plug
Open The Plug

To check the oil level, you will need to open this oil check plug; get a drive ratchet and turn the bolts unless they come loose. Now open this cover and you will be able to see the oil inside. 

Step 5: Check the primary oil level

Check the primary oil level
Check the primary oil level

You should see a dipstick attached to this previously opened cover and you will need to use this to measure the oil level. Take the dipstick and clean it properly with a cloth and reinsert the dipstick inside the oil. 

Now again take out the dipstick and check the oil film on the dipstick and this will show your oil level. Once you have the reading, check to see if it is at the appropriate level. 

Step 6: Secure the cover back on place

If the primary oil level is at the required level you may need to change oil, Simply put back the cover and secure it with the bolts.

Read Also: 6 Best High Performance Clutch For Harley Davidson

How To Change The Primary Oil on Harley Davidson

After checking the primary oil level on your Harley Davidson, if it’s below the required level or it seems contaminated or maybe too dark in color you will need to change the oil.

Step 1: Drain the oil

To check the primary oil level in your Harley Davidson you have used the primary oil check plug which is located near the primary chaincase. 

However, to change the oil you will need to drain the old oil completely. Find the primary oil drain plug on your bike, which is usually right below the primary case. 

Put a drain pan under this, open the plug, and wait until all the fluid is drained out. Make sure to put on a pair of gloves while doing this, as primary oil can be very tacky to work with.

Step 2: Change the gaskets

Change the gaskets
Change the gaskets

The primary case gaskets are pretty cheap and they get worn out after being continuously used. so it’s better to replace it when changing the oil. 

Remove the gasket from the primary case and replace it with a new one; simply just push the gasket on the case and the grooves will hold it in place.

Read Also: Harley Fork Oil Capacity Chart [A Quick And Easy Guide]

Step 3: Clean the plug 

After replacing the gaskets, clean the plugs very well and put it back in place. Use o-rings to securely tighten the plug. 

Step 4: Refill the oil

Once you have securely placed the primary plug, you will need to refill back the primary oil. Make sure to use oil recommended for your engine type and model. 

Get a funnel specifically designed for refilling primary oil in your Harley and start pouring fluid into the primary chaincase. 

Make sure not to overfill your bike, only fill the required amount and put back the primary cover and secure it.

Read Also: Harley 6 Speed Transmission Oil Capacity: Shift Gears Smoothly

What are the Main Uses of Primary Oil on Harley Davidson

When your Harley Davidson bike runs out of primary oil, your bike can never deliver its ideal performance. 

Additionally, your bike is more likely to run into several issues. So it becomes extremely important to do proper maintenance on the primary oil.

Lubricate parts

The main function of primary oil is to lubricate all the internal components of your bike, including the engine, for optimum performance. When the oil gets old or contaminated, it can no longer provide lubrication.

Helps in heat dissipation 

It also helps to dissipate heat properly which is produced from engine, clutch and other components in the bike. So, when oil becomes too low, it cannot dissipate the heat properly which can cause severe issues.

Better Fuel economy

Primary oil can reduce friction that can technically result in less fuel consumption and better use of the fuel. So, if the primary oil is not of good quality or gets contaminated it cannot work properly in reducing friction.

Read Also: Who Makes Harley Davidson Oil? Things You Mightn’t Know!


It can be a bit tricky to understand how to check the oil properly and our FAQs below will help you understand this more clearly.

How Often Should You Change The Primary Oil In Your Harley Davidson?

According to Harley Davidson you should change the primary oil every 5000-6000 miles or at least once a year. However, it also depends on your usage and driving conditions and your user manual should have the exact numbers.

Is It Necessary To Change The Primary Oil On Time?

Changing the primary oil in your bike is important as not changing it on time can really damage your bike. Additionally, the oil can form sludge and clog up the transmission system along with premature wear on the clutch plates.

Can I Use Any Type Of Primary Oil On The Harley Davidson Bike? 

You cannot use any type of primary oil on your Harley Davidson bike. There are specific primary oils specified and you need to follow those. Additionally, the oil can vary depending on the engines and your Harley model.


Regular checkup of the primary oil on your Harley Davidson is one of the important considerations to ensure optimum performance of your bike.

So, knowing how to check the primary oil level can be really helpful for any Harley users.

Always make sure to use the recommended oil for your bike and change them on a regular basis according to manufacturer recommendation.

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