Clutch slippage???

2013 STS, 998 twin, 44,000 mostly fun miles

Lately noticing a slight rev after gear shift up and down; sort of oozes into new gear, used to snap into next gear. Feels like clutch is slipping.

Couple of questions, first, is the clutch going to slowly slip more and more, or is there a chance of catastrophic stranding failure? Is there anything that can be done to verify if it is the clutch? Also Is the master brain capable of detecting slippage and generating a code or two? And last, ride until it totally quits, or will riding it cause further damage?

Guess I didn't keep it spinning fast
enough or possibly the 2 low oil incidents have taken there toll?

Any help appreciated.

Spyderfish

You have run it low on oil twice? And when was your last oil change, what oil are you using and do you change your trany filter when you do?

Slippage is almost always due to using the wrong oil. If this is the cause, and you catch it soon enough, you can save your clutch by changing the oil.

Thank Ron and Mike.

Regarding oil, last change before slipping was at 42,000 miles, BRP syn blend. Slipping did not start until 3,000 miles after that change, 45,000 miles. I changed the oil as soon as the slipping started at 45,000. Really not sure how to interpret the signs here. I am tending to just replace the clutch and forget about the causes, seems like poor maintenance decisions on my part.

Maybe incorrectly I assume you have the manual transmission, so I would suggest a clutch bleed with fresh fluid. If it's never been done, it's way past due and could be your problem.

Since you're using BRP oil that should eliminate that potential issue, unless you grabbed BRP 2 stroke oil by accident.

Running your bike low on oil shouldn't be too much of an issue, unless you ran it dramatically low. The old 996 engines burned oil and it's not unusual for them to get low over time without worry. A full quart between changes is normal and within the range of tolerance.

As to codes. No. It won't throw a code for a clutch slippage unless it's related to some other issue.

IF you have an SM5 Spyder go out on it get up to maybe 40mph and in 5th gear and open the throttle wide. The motor will increase in speed but the Spyder will not if you have clutch slippage.

When I traded my V-Max at a dealer, he put the front wheel up against a brick wall, got into top gear with the clutch pulled then increased engine speed & slowly engaged the clutch. It stalled, showing clutch was gripping just fine.

His transmission is the SE5.

Quote:

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Originally Posted by KX5062

Maybe incorrectly I assume you have the manual transmission, so I would suggest a clutch bleed with fresh fluid. If it's never been done, it's way past due and could be your problem. .......

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His sig line says 2013 STS SE5, KX; so it's probably the centrifugal clutch & not the manual! :dontknow:

The centrifugal clutches do suffer & will fail eventually if the operator loads them up too much at 'less than fully engaged' revs, which is why you really NEED to ryde so as to keep the revs up over about 3200/3500 or so on the SE5/Centrifugal clutch equipped Spyders. And those '2 low oil incidents' you mentioned Spyderfish, probably wouldn't have helped much either!! :gaah:

So yeah Spyderfish, I reckon this is a worn clutch issue, but it's probably the CENTRIFUGAL part of the clutch that's worn enough to create what you're experiencing. Yes, it WILL only get worse over time, and there WILL BE an increasing risk of catastrophic failure & stranding!! :shocked: But it shouldn't be too much of a problem to fix, just so long as you can still get the parts :rolleyes:

So, for my 2 bob's worth - go ahead & fix it now, learn from your mistakes & keep both the revs and the oil up to it from here on in, so you can happily ryde on trouble free for the next 100,000 miles or more! :ohyea:

x2:agree: Good luck!! Keep us in the loop!!

Quote:

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Originally Posted by oldgoat

IF you have an SM5 Spyder go out on it get up to maybe 40mph and in 5th gear and open the throttle wide. The motor will increase in speed but the Spyder will not if you have clutch slippage.

When I traded my V-Max at a dealer, he put the front wheel up against a brick wall, got into top gear with the clutch pulled then increased engine speed & slowly engaged the clutch. It stalled, showing clutch was gripping just fine.

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And is the wall still standing????? I still have my '98 Max and get into the V-Boost too often----- but it puts such a big grin on my facha.

Lew L

My 2012 RT with the SE5 showed the exact same symptoms and yours. I phoned the dealer and spoke with the technician and he said it could be a couple of different things.
Being convinced that it was the clutch slipping I rode it to the dealer the next day for the tech to ride it. Within 200 yards he said “it’s the clutch”. Not an inexpensive fix but it did fix the problem. As a side note, after the clutch was done, there was a growling noise when It was started cold and then put in gear. The noise lasts for about 50 feet and then it’s gone for the rest of the day.
There is a BRP bulletin that describes this exactly when replacing the clutch on the SE5. I kept the bulletin for quite a while but no longer have it or I’d share it with you.

Quote:

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Originally Posted by Lew L

And is the wall still standing????? I still have my '98 Max and get into the V-Boost too often----- but it puts such a big grin on my facha.

Lew L

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somewhat off the OP's topic (sorry). I put resistors in the v-boost electrical circuit so that it could come on at 3000rpm. I put a switch in the circuit so I could go to the original 6000rpm or to the 3000rpm one depending upon my mood. The small gas tank was a pain when in 3000 position.


Sorry for the distraction, spyderfish!

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Originally Posted by Wrongway

....As a side note, after the clutch was done, there was a growling noise when It was started cold and then put in gear. The noise lasts for about 50 feet and then it’s gone for the rest of the day.
....

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All the 2013 Spyders came out from the factory with & any newer replacement clutch units would have heavier/more robust steel plates in them, causing this particular noise - but also making them more robust & a fair bit harder to wear out! :thumbup:

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Originally Posted by BajaRon

Slippage is almost always due to using the wrong oil. If this is the cause, and you catch it soon enough, you can save your clutch by changing the oil.

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This might be the issue of buddy's incoming 2012 RS-S project. We'll just finish installing the shocks and skid plates from 4Wheelonline onto the current Wrangler project and he'll take a closer look. The owner had no idea what oil his son used for riding it in about 2 years.

Well, curiouser and curiouser. Reading the service manual regarding SE5 operation, more puzzling information. There are several solenoid driven valves on the Hydraulic Control Module that manage shifting on the SE5. One of the solenoids controls the "speed of clutch engagement for smooth operation".

Anyone have understanding of how a hydraulic valve is able to modulate a centrifugal clutch?

The centrifugal clutch engages and disengages mechanically the clutch based on rpm. When it is time to shift. The bleed (bypass) valve closes and the HCM system pressurizes. That oil pressure overrides the engagement of the centrifugal clutch with a piston. When the shift has been made. The shift computer will start pulsing the bleed valve to release the pressure. The rate of the pluses controls how fast the clutch disengages. That is determined by the shift computer by all its inputs. You may have noticed if if you increase the throttle just slightly during the shift. The clutch engagement will take a long time. Greater difference in rpm between both sides of the clutch. Slight decrease in the throttle during shift will make a fast engagement. Less difference in rpm of both sides of the clutch. All done to try to get a smoother engagement. Not always successful.

Quote:

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Originally Posted by billybovine

The centrifugal clutch engages and disengages mechanically the clutch based on rpm. When it is time to shift. The bleed (bypass) valve closes and the HCM system pressurizes. That oil pressure overrides the engagement of the centrifugal clutch with a piston. When the shift has been made. The shift computer will start pulsing the bleed valve to release the pressure. The rate of the pluses controls how fast the clutch disengages. That is determined by the shift computer by all its inputs. You may have noticed if if you increase the throttle just slightly during the shift. The clutch engagement will take a long time. Greater difference in rpm between both sides of the clutch. Slight decrease in the throttle during shift will make a fast engagement. Less difference in rpm of both sides of the clutch. All done to try to get a smoother engagement. Not always successful.

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:agree: annnnnnnnnnnnnnnnd all the above occurs in " milli-seconds ". .... Mike :thumbup:

Thank for the great explanation of the shift process, Billy.

The perceived slipping appears to happen after the shift while the hydraulic clutch is disengaging. There is a slight increase in rpm for maybe a second and then the rpm drops and everything is normal and feels solid. In terms of smoothness, this extended 'sloppy' shift is actually smoother, it used to 'thunk' after going into the next gear.

To the uninformed like me, this shift process seems like a minor miracle repeated every time the lever is pushed. And as Blueknight pointed out, in the blink of an eye. At the same time, looks like there are a lot of components that can cause this process to go south. Based on the complexity, I think I am tending toward a dealer visit to check the hydraulic functions with BUDS, getting a solid diagnosis before making any decisions on repair.

Thanks for all the info and time.

Spyderfish

Closing out this thread, and forwarding some information that may be helpful to other 998 owners.

I was suspicious about this slippage because it only seemed to occur when shifting. Turns out that this problem is not the clutch slipping but rather a dirty shift shaft. Because this 2013 has many heat issues, I removed the lower panels to increase air flow which helped quite a bit. However, With the panels removed the shift shaft is exposed to road dirt and moisture. The linkage appears to be a precision hardened shaft which extends from the shift valve to the transmission. There is a rubber boot that protects a portion of the shaft, but there is still a section of the shaft that is exposed to road flotsam and jetsam. This shaft became dirty and a little bit corroded from road grime salt etc.

Evidently, This dirt and corrosion was keeping the shaft from moving easily and it must have slowed down the change of gears and caused an interim loss of engagement which felt like a clutch slippage.

Cleaning up the shaft and adding a little lube fixed the problem and the shifting is back to normal. So if anyone has removed their lower panels for heat you may want to keep an eye on the shift shaft and make sure it stays clean.

This is my theory to explain the behavior, not sure if it's totally accurate but the shifting issue is corrected.:yes:

Sometimes it's the little things...

Just outta curiosity, do you let off the gas when shifting? If so, DON"T! Just keep the gas on and punch the paddles. Use the right oil and don't let is get low. I put 22K on my ST and never had a problem.