How to Change the Oil on a Harley Davidson Twin Cam Engine

A guide to finding the oil plugs & filling them to capacity

Harley Davidson oil changes can be pricey. Dealerships typically quote $225 for this service. If you're someone that isn't afraid to get their hands dirty, read this article and learn how to save some money. The example used here is an 88 cubic feet (2.5 m³) Softail. Always make sure to consult your service manual to make sure you are referencing the proper fluid capacities for your bike.

Things You Should Know

Empty the engine oil tank and fill it with fresh oil. The engine oil capacity is about 3 quarts (2800 ml).
Drain the transmission and refill it with fresh fluid. The transmission holds 24 ounces (710 ml).
Drain the primary chain case and fill it with oil until it reaches the bottom of the clutch hub. This takes about 1 quart (950 ml) of oil.

Steps

Download Article

The oil needs to be hot and thinned out before you can drain it.
There are three places you need to drain your oil from: the engine, transmission, and primary chaincase. The drain plug on all three of these pans requires a 5/8" socket or 1/4" Allen wrench to remove.
Advertisement
This will allow your old oil to flow out of the bike faster.^{[1]XResearch source}
This is easiest to get to from right side of the bike. You will need to use your 5/8" socket.^{[2]XResearch source}
You will need to use a 3/8" Allen wrench.
The transmission drain plug it centered directly above the shock absorbers. Because both the engine and transmission drain plugs are so close to each other, they can easily be drained simultaneously into the same drain pan.
Now that your engine and transmission oil are draining, stand your bike upright until oil stops running out of the holes. This is important to get as much old oil out of the bike a possible.
^{[3]XResearch source} There are magnets embedded in the end of each drain plug. These magnets collect any metal shavings produced from normal wear in the engine and transmission. Furthermore, inspect the rubber o-rings on the plug. If they are worn, they must be replaced.
You may want to use a torque wrench to tighten the plugs 14 to 21 feet (4.3 to 6.4 m)-lb; otherwise, tighten until the plugs are fully seated and not stripped.
^{[4]XResearch source} Place your drain pan under the front end of the engine. While removing the oil filter, use the oil filter drain funnel to make sure you don't make an oily mess on the bike or the floor. Alternatively, you can shove a rag under the oil filter prevent a mess. Have several rags on hand because this can get very messy.
When installing a new oil filter you must always lube the new oil filter gasket with a little bit of motor oil.^{[5]XResearch source} Screw the filter on until the gasket makes contact with the oil filter housing, then turn it another 3/4 or a turn. This must always be done by hand. Never use a wrench to tighten an oil filter.^{[6]XResearch source}
This is the beginning of the final leg of your oil change. Find the drain plug in the bottom side of the chain case. Place your drain pan under the plug. You will need to use a T-30 to turn the plug out. The picture of the plug's location is in next step.^{[7]XResearch source}
While the chain case is draining, remove the derby cover. The five bolts on the derby cover are removed using a T-27.
If it is in good shape, don't bother replacing it.
This is best done by using a primary chain-case funnel. Fill until oil reaches the bottom of the clutch hub. This should take 1 quart (950 ml; 33 imp fl oz).^{[8]XResearch source} In the photos, a chain-case funnel was not available, so it was fashioned out of a scrap piece of plastic.
When you do this, make sure to use a torque wrench. Those bolts are extremely easy to over-tighten and strip the threads. When torquing, make sure to tighten in a star pattern.
The engine oil capacity is 3 quarts (2,800 ml; 100 imp fl oz). Most likely there is still oil left over in the sump, so fill it with 2 quarts (1,900 ml; 67 imp fl oz) and check the dip stick. Add oil until the oil level is between the low and high indicators on the dip stick. Replace the fill cap.
The transmission holds 24 ounces (710 ml).
Once it is at an operating temperature, check for any leaks.

Community Q&A

Search

Add New Question

Question
Are all oil levels checked while the bike is on its side stand?
Community Answer
It depends on the model year. Check the manual. Mine is a 12 Heritage and everything is checked on the kick stand. On older models, it's up.
Thanks! We're glad this was helpful.
Thank you for your feedback.
If How.com.vn has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support How.com.vn
Yes No
Not Helpful 4 Helpful 4