SM5 Clutch Slipping

[BajaRon]

I'd be surprised if the blended oil met JASO MA2 standards. If they are labeled at all, it would likely only be JASO MA. I know of no MA2's except full synthetics, but there might be some. I don't think the BRP oil is JASO labeled at all...and they do not specify a JASO rated oil, unless they recently changed.

For those that don't know, JASO used to rate motorcycle oils that have passed their specs and tests "MA" if the oils were suitable for motorcycle wet clutch use. A few years ago they broke that rating into two parts...MA1 which was the the "slipperier" end of the rating, and MA2 which provided the very best grab. Both are usually suitable, as are most of the old MA rated oils, but for the least likely to cause clutch problems and slippage, choose the MA2 rated oils. They are the very best for wet clutch use and the MA1/MA2 standard is the most recent and most careful protocol...more defined than the old MA standard.

How'd I do Ron? I hope I didn't tell any lies.

I know a lot about some oils, and not a lot about a lot of oils...

You may be right about the blended oil ratings. I have no idea what the typical blended oil JASO rating is because I personally do not believe in using blended oils in anything. It's either worth going all the way (like my Spyder) or it gets straight oil (like my son's 1989 Honda Accord - You'd understand if you saw it :yikes.

But the fact that there has not been any significant slippage issues with the BRP blended oil means that it at least works ok. So that's what I'm going on there since BRP chooses not to give any information.

I do know that some have tried JASO MA (or MA1) rated oils and gotten slippage, changed (immediately) back to BRP, Amsoil or other proven oil and had no more problems.

There are certainly a number of very good lubricants out there that we cannot use in our Spyder specifically because of the wet clutch requirement.

 

[ulflyer]

Amsoil, Valvoline, Castrol

I've used all three, mostly Amsoil, and had a lab test done on all. Valvoline is, like Amsoil, synthetic and nearly as good. Both were shearing quite a bit at 3000 miles; from 40W down to mid to low 30W. Castrol too, makes synthetic, but they also make a ton of other weights in a BLEND. Since its been said Castrol makes BRP oil I decided to try it and ordered some off the internet. No local stores stocked it. Called Castrol Actevo Blend 10-40 Jaso MA2. I recently tested it, at 2000 miles, since I was dealing with a relative unknown. It tested at 2000mi about the same as Amsoil and Valvoline did at 3000mi. Not a very hardy oil.

The upside is my transmission is noticably smoother than before, particularly in reverse and shifting to first gear. Less clunky, smoother take offs. Previously, my reverse was sort of rachety; now its not. I'm thinking the blend has something to do with this.

The choice for me is, change frequently or go back to Amsoil.

Whether or not BRP is the same as Castrol is unknown as I've never used it nor tested it.

 

[gypsy_100]

You may be right about the blended oil ratings. I have no idea what the typical blended oil JASO rating is because I personally do not believe in using blended oils in anything. It's either worth going all the way (like my Spyder) or it gets straight oil (like my son's 1989 Honda Accord -

Agree on both counts. Seems like motorcycle oils are either regular oil or fully synthetic. Not blends. Can't say I've ever seen a blended motorcycle oil. Like you, I'd never use one. It's sort of like buying a fine wine and then diluting it with Thunderbird to save a buck (no offense to Thunderbird drinkers). I've been using full synthetic in all my cars since 1991 and routinely put over 200,000 miles on them. Current fleet is in the 150,000 range and doing fine. Full synthetic in the bikes, too, with my 'Wing having over 100,000 miles and no problems at all, including perfect clutch operation. For the other bikes, I settle for MA which has been fine, including the 'Wing -- sometimes Amsoil (MA2) and sometimes Mobil 1 which is MA. But because of reported slippage problems on the Spyders, I only use MA2 which usually means Amsoil.

 

[Lamonster]

I picked this info up searching around.

Found out what was causing the clutch slipping issues. Oil in the airbox should have been my number one area to look at. After exhausting all suggestions from all of you and still having a slipping clutch, it was the airbox at fault. On an RT there is a foam filter in the airbox on the left rear side of the airbox. This is the filter that filters air or gases from the crank case vent on the rear cylinder. When I removed the airbox there was a considerable amount of oil in the airbox. I removed the crank case vent filter and it was saturated with oil. Once it was cleaned dried and unit was reassembled the clutch did not slip anymore. So, long story short, excessive crank case pressure was cause of the slipping clutch. Thanks everyone for your input and I hope this saves lots of aggravation for someone else.

 

[bruiser]

I picked this info up searching around.

Now that is interesting.

 

[billybovine]

I picked this info up searching around.

Well that's a new and interesting angle for a cause to this problem.

 

[gypsy_100]

I picked this info up searching around.

Uh, could you explain the logic for that? I can't. The only thing I can think of is the higher crankcase pressure pushing on the clutch-assist diaphragm and causing it to partially release the clutch. But that's a stretch. I would think that would take a fair amount of pressure that would have easily been relieved by forcing its way thru the filter into the airbox. If it is correct, we should be seeing slipping clutches all the time on high-mileage RT SM's and I don't believe we are. I'm not saying his observations are not correct but that they may be unrelated and something else solved the problem. If you can explain it, I'm all ears. Thanks.

 

[finless]

I picked this info up searching around.

Remember the OP is talking about a SM5. I think that interesting tidbit might be fore the SE5?

Bob

 

[Lamonster]

Remember the OP is talking about a SM5. I think that interesting tidbit might be fore the SE5?

Bob

No this is for an SM5. Too much pressure in the case pushes on the assist / slipper diaphragm enough to make the clutch slip.

 

[BajaRon]

No this is for an SM5. Too much pressure in the case pushes on the assist / slipper diaphragm enough to make the clutch slip.

Well! Hush my puppies! You learn something every day!

 

[gypsy_100]

No this is for an SM5. Too much pressure in the case pushes on the assist / slipper diaphragm enough to make the clutch slip.

That was my theory but I just didn't think the pressure could get high enough to do that. Interesting. Wonder what made this one plug up and countless others not plug up?

Quote from Lamont's post;
Found out what was causing the clutch slipping issues. Oil in the airbox should have been my number one area to look at. After exhausting all suggestions from all of you and still having a slipping clutch, it was the airbox at fault. On an RT there is a foam filter in the airbox on the left rear side of the airbox. This is the filter that filters air or gases from the crank case vent on the rear cylinder. When I removed the airbox there was a considerable amount of oil in the airbox. I removed the crank case vent filter and it was saturated with oil. Once it was cleaned dried and unit was reassembled the clutch did not slip anymore. So, long story short, excessive crank case pressure was cause of the slipping clutch. Thanks everyone for your input and I hope this saves lots of aggravation for someone else.

I'm sorry, someone is going to have to explain this one to me. The cause here does not appear to be reason for the effect. Unless we are talking about possible low oil level on an SE model due to excessive amounts being sucked into the air box. Now that I can understand.

I don't see how crankcase pressure can inhibit clutch engagement. There have been cases reported on Spyderlovers where the crankcase pressure was high enough to blow out seals and no clutch slippage was mentioned.

The SM's have a vacuum assisted clutch mechanism. There is a large rubber diaphragm connected to the end of the clutch mechanism. When you start to pull in the clutch lever, intake manifold vacuum is used to pull on the diaphragm and assist you, thus making the clutch lever easier to pull. (Above 4,000 rpm there is no assist, BTW.) So my thinking, and LaMont confirmed it, is this. One side of the diaphragm is exposed to the vacuum source when the computer tells it to apply vacuum. The other side of the diaphragm is exposed to the crankcase area around the clutch. So if a vacuum pulling one direction on the diaphragm can assist in disengaging the clutch, then too much crankcase pressure pushing on the other side of the diaphragm could do the same thing, slightly disengaging the clutch when it should be fully engaged. I'll bet BRP never thought of that one.

 

[BajaRon]

That was my theory but I just didn't think the pressure could get high enough to do that. Interesting. Wonder what made this one plug up and countless others not plug up?



The SM's have a vacuum assisted clutch mechanism. There is a large rubber diaphragm connected to the end of the clutch mechanism. When you start to pull in the clutch lever, intake manifold vacuum is used to pull on the diaphragm and assist you, thus making the clutch lever easier to pull. (Above 4,000 rpm there is no assist, BTW.) So my thinking, and LaMont confirmed it, is this. One side of the diaphragm is exposed to the vacuum source when the computer tells it to apply vacuum. The other side of the diaphragm is exposed to the crankcase area around the clutch. So if a vacuum pulling one direction on the diaphragm can assist in disengaging the clutch, then too much crankcase pressure pushing on the other side of the diaphragm could do the same thing, slightly disengaging the clutch when it should be fully engaged. I'll bet BRP never thought of that one.

I see that you captured my display of ignorance before I could pull the plug on my post... That's the way it goes sometimes... pps:

 

[gypsy_100]

I see that you captured my display of ignorance before I could pull the plug on my post... That's the way it goes sometimes... pps:

I would never put your name and the "ignorance" word in the same sentence. But this is a weird one. I'm still not sure I believe it myself.

 

[thehawk]

I had a binding…

… clutch lever which exhibited no free play and caused some slippage. Dealer fixed it in five minutes. not sure what he did; but it's never reccurred ... now have 20,000 miles on the bike. 2011 RT.

 

[BajaRon]

I would never put your name and the "ignorance" word in the same sentence. But this is a weird one. I'm still not sure I believe it myself.

As I said in my first post. There have been owners with blown oil seals due to over-pressure in the crankcase and no complaints of clutch slippage. That is where I was basing my original response.

 

[rcturner]

I am no expert but was told the SM5 has a wet clutch. Check you oil level maybe?

Bob

Oil level has nothing to do with this issue. Oil type could.

 

[NancysToy]

That was my theory but I just didn't think the pressure could get high enough to do that. Interesting. Wonder what made this one plug up and countless others not plug up?



The SM's have a vacuum assisted clutch mechanism. There is a large rubber diaphragm connected to the end of the clutch mechanism. When you start to pull in the clutch lever, intake manifold vacuum is used to pull on the diaphragm and assist you, thus making the clutch lever easier to pull. (Above 4,000 rpm there is no assist, BTW.) So my thinking, and LaMont confirmed it, is this. One side of the diaphragm is exposed to the vacuum source when the computer tells it to apply vacuum. The other side of the diaphragm is exposed to the crankcase area around the clutch. So if a vacuum pulling one direction on the diaphragm can assist in disengaging the clutch, then too much crankcase pressure pushing on the other side of the diaphragm could do the same thing, slightly disengaging the clutch when it should be fully engaged. I'll bet BRP never thought of that one.

One source of clutch slippage and premature failure on the SM's has been the clutch assist solenoid. It is not a common problem, but a few of them have failed to shut off completely, leaking vacuum and causing the clutch engagement pressure to be less than it should. In time the clutch will slip and wear out.

 

[gypsy_100]

One source of clutch slippage and premature failure on the SM's has been the clutch assist solenoid. It is not a common problem, but a few of them have failed to shut off completely, leaking vacuum and causing the clutch engagement pressure to be less than it should. In time the clutch will slip and wear out.

That could be Chief-J's problem (the originator of this thread). Hopefully the dealer checks that out.