Harley has the most screwed up oil system but I use it to my advantage. to over come the oil left in the case, I do this. Harley's oil system goes oil tank to pump to engine to filter to tank since there is no plug in the case, after draining the oil I put a pan under the filter before installing the filter I put 2 qts in the tank, crank the motor and watch the oil drain into the pan until it's clean. it really works. Never run your engine dry of oil!!!!! 

At the price of Syn these days you just added 15 to 20 dollars to the oil change. I always run the engine till its hot before I do an oil change - which you should always do anyway - and that should ensure everything has enough oil coat on it to crank the engine for a second or two with the plug out. Plus with syn there isn't as much breakdown so if you add 5 qts change the filter and leave lease than a 1/2 qt in the case should not really be a problem.

Never really thought about it, but I guess there is a bit of oil left in the case.

I normally have a little over a qt left in the case. I'm happy with Dino. Mine is 4qt and it takes less than 3 to fill it after a change. so that's over 25% old oil left in the case. also mine is OLD 30yrs it goes through oil quicker than newer models

New 2014 dyna switchback , ready for 1000 mile service can't decide which oil to go with ,conventional or synthetic. What do you Harley guys recomend ?

I would personally recommend Syn on a newer bike!!!

there is always a little oil left in the case. I always use the same type of oil change after change. As long as you change your oil in a timely manner that small amount left in won't matter. At least it hasn't for me and I've been doing it the same way for years with no prob.

Here is a whole lot of discussion on Syn Lube vs Dino oil... http://www.cyclefish.com/forum/General/The-Garage/Synthetic-Lube-VS-Motor-Oil-74-1.html />

As for the oil left in the case I guess I kind of knew it was there but never really worried about it. I think the newer bikes have changed a bit because when I pulled the plug from the bottom of the case there was only about 1/2 qt in there. Plus when I re-fill it takes almost the entire 5 quarts.

I don't have a crank-case plug and being an older engine I like to do a complete change. This was the first time I captured and trashed the 2 qts of oil like I described but I must say my oil looks a lot better than it ever has.

I know know how it is man...

My '06 Dyna takes 3 qts for a dry capacity refill and 2.5 qts for a wet capacity refill. So a half a qt (roughly 16.6%) stays inside.

I'm pretty consistent on oil changes and don't much worry about contamination.

If Harley's not worried about the left over oil, then I'm not worried about it ether. Most Harley's are driven on paved roads and not in dirty dusty fields pulling heavy machinery. You should see the oil that comes out of my tillage tractors after 100 hours of hard work. It's thick and black as coal,

Just picked up a 2014 Slim. And plan to switch to Amsoil Synthetic 20W-50 for all three sumps.

these machines take oil..?? learn something every stinkin' day.

70 W all year round. If something doesn't leak... there is no oil in the bike

70W? That would make it burst at all seams.

manual calls for 70 w summer and 50W winter. Panheads are low pressure / high volume for oil.

115,000 mi. On my '05 EGlide using HD 20-50, changed every 5,000 mi. I use a vampire to suck most of the oil out the filler hole, then use the drain plug to get the rest. Still runs strong. Running Headquarters 034 gear drive cams & PCIII tuner.