From an engineer standpoint, a non filtered system should not have a high detergent additive. A oil wet clutch should not have a lot of EP or other additives in a motor oil.

For a while, after Synthetic, Mother Ship had said SYN in all three holes. Few years ago they switched back to Formual + as first choice in primary and transmission.

I personally think there was a reason. Probably the warranty inssues was a determining factor.

Use a 15W-50 or 20W-50 high detergent motor oil in motor.

 

I agree, Rip, but what I'm asking is; would there be any harm done to the primary or trans by running the 50W in them? I wouldn't think so, but I figured I'd ask others for their opinions and experience.
If it matters it's an '04 Ultra. 55K miles.

 

 

I am going to assume you are referring to 50W High detergent motor oil.

I am not reference other then what the oil engineers have said about a HD (high detergent) oil in a non filtered gear box. Do I personally think it would hurt? Heck no.

Supposed that HD keeps crud in suspensions so filter catches it. By using non detergent, the crud settles out and stays on bottom of box.

In a Harley transmissions and primary, they are probably like probably like one of those dish washer displays with a glass door.

However, I have scraped crud off the bottom of both.
I sell engineering facts as best as possible. Sure not a tin man. This is my hobby and my labor is always free.

PS. For years, small motor maker Briggs and Stratton always had a warning only use 30W non detergent oil in their not filtered small gas motors.
Rarely do Harley's wear out. In fact, those with the most dedicated of owners who have their bikes serviced to a T die the quickest.

 

 

Been using Mobile 1 15W-50 in the motor hole for years. Ran 5W-20 in RIP's CR-V we purchased new. Had a little over 100k on it when I gave it to a grandagrandda for college

I changed the oil at around 10K.

I replaced plugs for first time and checked the valve clearance before giving it to her.

It has a similar link chain dual camshafts but massive delrin guides
Engine was spotless inside other then a little varnish red stain. Cam timing was dead on.
That is my test bed for my words. No tin man bullshit. I do my own work and look in side.

I took pictures but not on my phone and I am out of the country..