Clutch Problems - FAQ's

Question #1: ~ Lately, when I ride my Cade and am shifting through the gears and getting on the gas to merge onto the freeway, I notice what seems to me like the clutch slipping.  I told my mechanic about it and he said that even though the engine only has about 12,000 miles on it the clutch plates are so old that they are probably glazed and need replacing.

Answer #1: ~ Rick Gervasi, of Gervasi Cycle Repair says that most of the clutch problems he has seen have more to do with the clutch hydraulics than the plates.  He recommends you flush and bleed the clutch hydraulic fluid.  Then check the clutch master's return "bleed off" hole.  This hole can be plugged or even just partly clogged, sometimes the older bikes even have this hole corroded.  Clean the return hole and rebuild the clutch master making sure the return "bleed off" hole is clear.  If this doesn't solve the problem, you may need to replace the clutch friction plates; springs and possibly steel plates will be required.

Question #2 ~ I am new to my Cade still and have a question about clutch slippage.  Is there some level of slippage expected with these bikes?  I know there is a lot of mass (especially when I'm on it) and a very powerful  
motor.  I have had the clutch slip twice in a couple weeks when I was getting on the throttle pretty heavily after a rather quick clutch engagement.  The bike has 37K on it and was used to pull a trailer the last two years before I bought it.  I have no qualms about getting into the clutch and changing parts, but I sure would hate to do that and then have exactly the same symptoms I started with.  I have put on about 500 miles with only two occurrences of slippage.  I would like to know whether I am seeing signs of a clutch about to go bad or just normal response to a driving style that I probably shouldn't be engaging in anyway. ~ Chuck


Answer #2:  ~ I am not familiar with your problem. However, fluid breakdown does seem viable.  The owner’s manual does suggest changing the clutch fluid every two years.  And unless another remedy is identified up front, it would be the least expensive way to start. ~ Bob

Question #3: ~ When I took my trip to Florida last week, I noticed that when I ride for 50 to 100 miles, I don't seem to have any "feel" in the clutch.  By 
this I mean when I squeeze the clutch lever to down shift, there doesn't seem to be anything there.  It does "pump up," but it doesn't do this in town, or sitting over night.  The only time it does it, is when I've ridden at high speed for a while.  High speed to me is 60 to 70.  Could I have air in the line?  I thought about this, but I figured it would do it after sitting for a few days.  It doesn't.  What about the fluid breaking down?  I'm not using any fluid.  The reservoir has been at the same level for several months.  I don't have a problem with my clutch slipping under load, but I do have "hot spots" that you can feel on take off.  Take-off’s are just a little jerky.  It's been this way since I got the bike.


Answer #3: ~ Air in the system is unlikely. Just like brakes, air in the system is indicated by a "soft" feel and cannot be resolved by "pumping".  Even with air in the system, when the slack is taken out, it won't pump up any more. If it requires a pump or two to get the feel back, then there is most likely slack in the system.  Now, why does it happen when you ride and not when it's parked?

Just like disc brakes, the clutch slave cylinder (at the motor) probably uses a square seal (not an o-ring).  There are a couple of reasons why they don't use an o-ring, but one is that an o-ring tends to roll as the piston moves in the bore.  As you release the clutch, the rolled o-ring wants to return to its prior, natural, unrolled shape and can pull the piston back in the process creating slack.  A square seal doesn't roll, it just slides across the surface and leaves the piston in the position in which the pressure of the fluid on the back side (which should be at or near zero) and the pressure from the clutch springs equalize.

But, if the slave seal is worn considerably, not to the point of leaking but worn, it may not have enough of a grasp on the piston to retain it in the equalized position if there is enough vibration during riding.  The piston could be working its way back into the bore ever so slightly creating the slack you describe.  Also, there may be a valve (possibly a reed type as I have seen on car master cylinders) on the end of the master cylinder piston that leaves some small amount of pressure (just above zero) in the system to prevent the aforementioned condition.  If the valve has become faulty, it could allow the engine vibration to work the piston back into the bore pushing fluid past the valve back into the reservoir.  The way to check if  this is happening is to accurately check the fluid level before a ride, then ride the bike a distance, or time sufficient to cause the condition.  Then, without using the clutch, bring the bike to a stop (it will be tough but I think that it can be done).  Now check the level again.  If the level increased during the ride, then the slave piston is pushing fluid back into the reservoir.

I would rebuild the master cylinder before the slave cylinder.  A cleaning might do it as well.  You can use the service manual on that test CD to walk you through it. ~ Tracy

Question #4: ~ Also, on the clutch problem, I too have noticed that the clutch seems to grab at the far end of the limit.  I was wondering if at 6000 miles on the Cade, is it possible the plates are starting to go?  The manual says  it's a self-adjusting clutch.  Is everyone else about the same place of engagement?  ~ Davybee

Answer #4: ~ Hi Dave, I would have a hard time thinking that a Cavalcade clutch was finished at only 6,000 miles.  I think you would have to do a lot of “burn-outs” to lose a clutch this quick.  I think there are some Cavalcades out there with about 80,000 miles that still have the original clutch.  The Cavalcade has more clutch disks than most other bikes.  If I'm not mistaken, there are 11.  Most other bikes have 9 or less.  I think the Gold Wing has 9.  That's a lot of "bite."  That's also a lot of clutch to wear out quickly.

Question #5: ~ I don't have a problem with my clutch slipping under load, but I do have "hot spots" that you can feel on take off.  Take-off’s are just a little jerky.  It's been this way since I got the bike.  Anyone have any ideas? ~ Bob

Answer #5a:  ~ From the description of "jerky takeoffs" sounds like your clutch fluid in the master cylinder, hose, and slave cylinder is old and contaminated.  You may even have crystals.  The brake fluid should be flushed out not just drained from clutch and brake lines at least every 2 years.  This is best done with a vacuum pump at the slave cylinder.  Oh by the way, brake fluid and plastic don't mix be careful. Slippage should not happen due to contaminated fluid, that's more a function of clutch material, oil and more so the springs tension. ~ Al, California

Answer #5b:  ~ You need to read your owner’s manual.  It tells you that you need to change your fluids every 2 years or 24,000 miles.  The fluid does break down. I would be very surprised if you have any air in the system.  The grabbing you are describing could be caused by some corrosion that has formed inside the clutch release cylinder.  The same type of corrosion that forms inside brake calipers and then causes them to stick.  This ring of corrosion is preventing the piston inside clutch release cylinder from moving smoothly thus causing your grabbing clutch.  Hope this helps.  ~ Jeff (My clutch was letting out very close to the grip. Replaced at 45000.  Very easy to change)

Answer #5c: ~ Since I'm new to Cavalcade_ USA I would like to add some of my experiences to the group.  I have two Cavalcades, both 86's, one LX with 44k miles and one LXE with 23k.  Both have a jerky clutch especially with a load such as two up and a trailer starting out.  Shifting on both from 1st to 2nd is harsh or a grinding of the gears.  The LX had Castrol 10w40 when I bought it in 1988 and I continued to use it for some years before changing to Suzuki 10w40.  I may be wrong, but me working for a motorcycle dealer makes me believe that the manufacture has an additive in the oil that is good for both the engine and clutches.  The owner’s manual does suggest this oil.  I also change my oil about every 2,500 miles.  This is especially good when only making short trips and the engine not reaching normal operating temperatures for any length of time, to remove the condensation created by temperature changes.  Brakes and clutch fluids, these should be bled every two years as suggested by the owners manual.  I did have all the hoses, fluids changed once.  The cooling system was left with an air pocket and the rear brake locked up on the way home from the dealer.  Needless to say I do most of my own work.  I have had to replace the clutch slave cylinder on the LXE, which is no easy chore.  I also rebuilt the brake calipers and cylinders and flushed the systems with DOT 5 fluid.  There is not a rebuild kit for the clutch slave at a dealer.  A new cylinder is about $75.  So far so good.  I put lots of thought into using DOT 5 and find that it does not collect moisture or take the paint off if spilled.  Moisture is the reason for changing brake fluid every 2 years.  ~ In Gods Service, Tom


Question #6: ~ I accidentally overfilled my oil level by about 3/4 of a quart before a trip this past weekend.  Would that affect my clutch?  When we got almost home I smelled a little oil and when changing gears, on the interstate, the clutch felt very weak and didn't want to engage correctly.  After stopping for a few minutes and resting it was fine again.  Any ideas?

Answer #6a ~ It might be the combination of too much oil and grade of oil that could cause clutch problems.  I think the manual calls for a good grade of 10W-40.  I use Castrol 10W-50 and have no problems yet.  I have used lighter weight like 10W-20 and the clutch wouldn't work right when it was hot.  The clutch lever is hydraulic and has a reservoir on the left handle bar.  When it is low on fluid the clutch will not engage.  There is a round window to view the fluid level, but it's hard to see.  Remove the two screws on the top of the reservoir and lift the cover to check fluid level.  Add dot 3 or 4 fluid if  it's low.
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Answer #6b ~ The clutch is non-adjustable.  If there is any slippage, you have to 
replace the plates.  The only thing you might use to remove the slime is wood alcohol, but since you have to tear the clutch assembly apart and you have 50k on the bike, you might as well replace it. ~ Regards Mike C.

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More On Clutch Slippage

I bought my Cade from a guy who pulled a sidecar for 10K, and sold it to me with about 38K on it.  The clutch was slipping when I bought it and I'd already deducted $250 from the purchase price.  Half throttle would break the clutch loose in 5th gear. A new set of FRICTION plates cleared the problem up.  My dealer maintains a fleet of Cavs the ABC Studios use for their "shagger" or couriers.  They know these bikes well and mentioned the plates were glazed, and they could see where I was trying to break the glaze off.

The bike has too much torque to play around with cheap fixes... buy yourself a new set of plates.  There should be no slippage at all. The trailer did the same thing the sidecar did, added enough stress to the drive train to shorten the lifespan of the clutch.

 Donald Box
dbox@ktb.net

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Information On Clutch Fluid Loss


I have read several inquires as to loss of fluid from the clutch reservoir.  I also had this problem and later had to replace the clutch slave cylinder, which is bolted to the back of the intermediate gear box.  If this turns out to be the problem, you SHOULD also replace the drive shaft seal, the clutch rod seal, and the main shaft seal.  If you don't, you will probably have to in the near future after reassembly of all the parts you had to remove in the first place. 

Take it from experience, those seals are my next winter project.  I HOPE I can baby them thru this summer.  There's an indication of main seal transfer of engine oil into the intermediate gear box.  There is a strong odor of HOT GEAR OIL after a hard run OR HIGH oil level in the intermediate gear drive and an unexplained loss of engine oil (1/2 quart) with no evidence of an oil leak after approximately 200 to 300 miles.

 When you have this intermediate gear box OFF, by removing the stator cover you can also visually check the U-joint for slop (as you can pull the shaft out the front of the torque tube) and also lube those rear drive shaft splines.

Clutch slip in 5th gear could also be fluid NOT returning to the reservoir, Over fill or return orifice plugged, or air gap in top of reservoir cover bummed up OR slave cylinder not returning to normal position after clutch engagement (binding).

~Walter