I recently changed my engine oil, for the first time, on my 06 Heritage Softail. As instructed in the service manual I drained from the drain hose attached to the frame. Later I noticed another plug that might also drain the engine oil that was located closer towards the oil filter. It appears that this other plug sat lower in the engine block and might of help in draining more of the oil.

Does anyone know if this assumption is true or what this other plug might be for?

 

The crank case oil drain plug is located on the frame on near the swing arm, under the oil tank. On a sportster it is a hose that is clamped underneath the bike. You can also use the oil line to drain the engine. There is one drain plug for the crank case, one for the primary, and one for the transmission. So a total of 3 drain plugs to drain different oil from each time you change the various oils.

 

I have a Heritage Softail and I am aware of the three separate drain plugs for each reservoir. However there is another plug underneath the engine block about 8 inches from the front in the lowest section of the engine block.

Anyone else have any ideas?

 

There is a crankcase drain plug which will drain about 8 ounces of which remains in the crankcase when you change the oil. Don't be tempted to remove it to drain this oil. I have heard of getting the plug cross threaded which & you can guess what happens. That small amount of oil remaining is no biggie.

 

That is a fact. If you insist on draining every last drop from the crank case get the Rogue chopper tool and use that. It is not necessary however. I have never used this method and am yet to have any sort of problems.

 

Thanks for that information, this is what I kind of thought.

I noticed that the oil was black after I drove around the block and then check the oil level. I realized that I must not of drained all of the old oil out.

There must be another reason why this other plug is there and the manual does not refer to it when draining the oil. Maybe something to do with the oil pump loosing it's prime if all of the oil is drained out.

Anyone else have an opinion?

 

Leave it alone. All sorts of bad things can happen if you don't get that plug back in right.

 

Okay, enough said. I promise I won't even think about that extra drain plug. This topic is put to rest, IMO.

Thanks to all that have offered their help and/or suggestions.

 

Just remember to change your oil after letting the engine run for a few minutes to pump the oil back out of your crankcase back up to the oil tank..
If you haven't ridden your bike in a week or two and go out and drain the oil cold.. a quite a bit more oil will have flowed back into your crankcase over the weeks and when you fill the oil to the proper level in your tank afterwards, and start your bike.... pop...you'll have oil all over the place as your oil tank cap is blown out from the overflow...

don't ask how I know after my first oil change....

 

3 if you count the oil filter as a drain