How Often Do Harley-Davidsons Need A 3-Hole Oil Change?

To some folks, performing an oil change may be therapeutic or even enjoyable, but most enthusiasts would rather be driving or riding instead. If there's a silver lining to completing an oil change on a motorcycle vs. on a car or truck, it's that everything is accessible. No more lying on your back to wrestle with a spin-on oil filter while 5W-30 runs down into your armpit. However, the bad news about changing the oil on most Harley-Davidson bikes is that there are actually three different components which require periodic oil changes. 

Of course, the first order of business is the oil inside that iconic V-twin engine. Per Harley-Davidson owner's manuals, a Big Twin's engine oil and oil filter should be replaced every 5,000 miles or every 12 months, whichever comes first. The exception to that rule of thumb is when the bike is brand new. For brand-new bikes undergoing the break-in period and the associated tiny metal particles, Harley recommends fresh oil after the first 1,000 miles and 5,000-mile (or annual) intervals thereafter.

So, what are the other two "holes" that require periodic draining and refilling with fresh fluids? Those components are the transmission and the primary, the latter of which connects the engine and transmission via a sturdy chain. Although many Harley riders use the same type of lubricant to service all three components — engine, transmission, and primary — note that the service interval frequency does vary between them.

On a brand-new bike, Harley-Davidson recommends that all three holes get fresh oil after the first 1,000 miles during the break-in process. However, following that initial whirlwind of maintenance, the recommended intervals start to stagger. For the primary, Harley suggests changing the oil every 10,000 miles. Meanwhile, the transmission requires fewer oil changes still — every 20,000 miles, to be specific. 

To answer the titular question, modern Harley Big Twins will get a three-hole oil change after their first 1,000 miles, then every 20,000 miles after that. Of course, the engine and transfer case "holes" will need more frequent oil replacements in between the comprehensive three-hole changes. Harley owners should also be aware that the manufacturer recommends more frequent oil changes under a litany of circumstances that it deems to be severe conditions. Those severe conditions include extreme temperatures, stop-and-go traffic, frequent short trips, dusty dirt roads, and adventure motorcycling in the mountains, just to name a few.

At the risk of going down a rabbit hole, many riders opt to use the same oil in all three holes. Such oil may be labeled "motorcycle oil" instead of just engine oil to indicate that it's also suitable for use in transmissions and primaries. If that sounds like the worst idea ever, oil companies are more than happy to sell you dedicated primary fluid and transmission fluid instead.