15w50 oil in 848

B

Brendon

New member
I do know about the contracts. My comment was aimed at the viscosity of the oil. Many folks get all worked up over that but it's just not that critical if you're running the weight stated. I do feel the factory knows what viscosity is best to run in their motors. I'm not an engineer and I am incapable of determing those types of things and am at the mercy of the lubricant marketing departments as I imagine most of us are.

Branding is a whole other issue. Who really know's what's best? Way too many factors involved. My opinion? run with known quality lubricants and it's a done deal.
 
Honestly......is the difference between 15w50 and 10w40 going to matter. No. it won't. Either weight will work in either bike just fine.
 
Actually here's the scoop on all wet Ducati clutches. The clutch assembly sits on the transmission main shaft. As part of the clutch oiling system there is a passageway that allows the oil to enter the clutch itself. In a portion of that passageway there is a check valve to shut off the oiling at idle. This is done to prevent the clutch plates from dragging. Heavier than 10/40 has the ability to bypass that check valve (i.e. force it to open) and dump excess oil into the center of the clutch causing it to drag.

It might be possible for different brands to by-pass that check valve despite the viscosity being the same. Long story short, if you're having no clutch dragging issues at idle with your chosen flavor of oil don't worry about.

The above information has been provided to me by a soon-to-be Ducati Level 3 Master Technician. I knew the basics but he was able to put it into greater techinical detail. My hat's off to Dennis.
 
Although oil is slippery it does create drag. Clutch plates run in extremely close proximity to each other in a multi-plate clutch. Because of the close proximity picture this:

1) You have 2 clutch plates extremely close to one another (yes, there are more than 2 plates total)
2) Oil has a certain thickness to it although it varies depending on the size of the area it is spread upon
3) When oil enters the clutch area the oil takes up "X" amount of space. The thicker the oil and the greater the quantity of the oil in a given area (example is the clutch itself) the greater the "thickness"
4) That thickness when combined with 2 adjacent clutch plates does not allow the plate to free up completely due to the "sticktion" of the oil
5) The fact that the plates cannot free themselves 100% from the oil creates drag
6) An example: You're at idle in neutral and you put the bike into gear. It jumps forward a bit. That happens because the clutch plates are not completely freeing themselves up from oil on the initial in-gear. Very quickly the plates will become free and you're bike no longer wants to move forward despite the fact the clutch is pulled in
7) The winter can make things worse as the oil is thicker than normal. In bad cases the engine may even stall when put in gear and/or noticiably jump forward when put into gear.

Simple example and explanation. Hope that helps.
 
Ya that's great explanation thank you for that, the only thing I would ask is that when the bike goes into first gear from what I read in superbikes or fastbikes magazine some time ago was that that hard shift into first is meant to do that.
So do you think going from 15w50 to 10w40 would have any affects at all?
 
It's common for a Duc to have a hard shift into 1st. My S4RS does that very thing. However, that hard shift has nothing to do with what I'm referring to.

What would make my description applicable in your circumstance is this question: does the bike want to jump forward when putting it into gear? Or, with the clutch held in does it want to creep forward for a very short amount of time and i do mean very short. That oil sticking to the plates in warm weather tends to be non-existent most of the time. It will however be worse when it's cold out.
 
Billy Walker said:
It's common for a Duc to have a hard shift into 1st. My S4RS does that very thing. However, that hard shift has nothing to do with what I'm referring to.

What would make my description applicable in your circumstance is this question: does the bike want to jump forward when putting it into gear? Or, with the clutch held in does it want to creep forward for a very short amount of time and i do mean very short. That oil sticking to the plates in warm weather tends to be non-existent most of the time. It will however be worse when it's cold out.[/quote
It doesn't wanna jump forward anymore than my 07 CBR600rr did, in fact both bikes had their hard and soft shifts(usually when the bike is warm ofcourse) into 1st.
So I guess the answer to which oil grade would be to stay with 15w50 then.
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The difference between 10/40, 15/40 and 15/50W is minimal, and not necessarily consistent across different brands. As Marlon suggests, changing the oil often is more important than which brand/grade you choose.
Wet clutches tend to be a bit 'sticky' immediately after an oil change, but should settle within a short ride. Billy's info re the 10/40 for the wet clutch models is worth following. I have used Motul 10/40W for the last 42,000 kms on my 1098, with no problems.
If your clutch is dragging, or doesn't go into 1st smoothly, bleed your clutch fluid - including at the master cylinder. This needs doing frequently on Ducatis, particularly if you have a larger-bore slave cylinder.
As to contracts - Ducati has changed affiliation from Agip to Shell over recent years, plus Shell have changed their motorcycle oils range, so some of the recommendations in owners' manuals are no longer available in the exact quoted weight.
 
ForzaDuc said:
I am not familiar with how a CBR600 feels when shifting and oil is not the only possible problem. In addition, I am not familiar with the clutch/oiling operation on that bike. If you're not confident in your own diagnosis, or you need confirmation of that diagnosis, you should go to a knowlegable and trust worthy Honda dealer for advice.
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