Well said 👍

Wiz

 

my thoughts exactly, that's why ive always ran Castrol diesel oil

 

I know I am extremely late on this post. I put Mobile 1 synthetic 20/50 in all 3 holes. I know we all have Harleys but when I had my Boulevard c90, It had one oil (20/50) for the one oil change that covered the Transmission, Engine and Primary. The same oil lubricated them all and it was an air/oil cooled engine. Why is everyone making the Harley application so difficult. The Mobile 1 states it is for all 3 holes. 2009 Street Glide with 80,000 miles. JMHO.

 

You had the engine replaced at 42,000 miles.

 

Only by a year and a day

 

Per an earlier post, engine oil is designed for engines and gear oil is designed for gearboxes. I suppose one could also use the same oil in the motor, manual transmission, transfer case, and differentials of a 4wd/AWD vehicle, but they benefit from different viscosities and additives designed for specific applications and some components would likely have shorter life. From Baker Drivetrain (pdf doc)

Using the same oil doesn't even save any money, so I don't see the point.

 

As a Trucker ( now retired) I always believed that motor oil goes in the motor and gear oil in the gearbox/axles/ differential. But I'm not a scientist or engineer. Just a nut on the end of a stick shift.If the designer/ builder says you can use motor oil in all three than good. But it makes me feel better to use gear oil in the gearbox. And feeling good is good enough for me....which reminds of a song...

 

Hi all, newbie here, first post.
I think the PO said he used HD synthetic in all three holes of the 2015 Ultra. The gears don't shift smooth and are noisy. I was told to use Bel*Ray Gear Saver. My question is, can I simply drain the synthetic and put the Bel Ray in? Will the remainder of the synthetic be okay with a mineral based fluid? TIA.
Mike

 

Short answer
Yes


I don’t know what Bel Ray is made of but it’s compatible

Ive used it for 30 plus years simply because the red color allows you to know instantly if that leak at back of primary is the chain case or tranny seal

I try to avoid oil threads but thought I’d throw that out there

 

Yes BUT !!!!!

Today with modern metals unleaded fuels and higher performance engine’s with increased red lines.

I don’t believe there is a one oil for solution.

My 2 cents

Wiz 🍻