Topic: cb500 clutch slips at low RPMs when warm *EDIT* I found a crack :/

[davis96]

Been searching, but so far no one has had quite the same issue.

A quick rundown of my issue: Everything works fine at first, but after riding for 15-20 minutes and the engine warming up, the clutch has a hard time engaging in first gear from a start. Starting in neutral, I'll pull in the clutch and shift into first. When I let the lever out, it feels like there's not enough pressure on the clutch side to pull the cable back into the sleeve (i.e. to engage the clutch). So I'll rev and rev with my hand completely off the lever, and the clutch won't grab. Is this just worn clutch plates/springs? Even once the clutch engages and I get moving, the clutch feels like its still partially disengaged (i.e. if I give it a bit of throttle, the revs just shoot up, until I get into a much higher gear).
Extra Info:
-I've adjusted the clutch per the manual
-The clutch cable was replaced not 2 days ago (Should I have to lube a brand new clutch cable?)
-The bike has about 9500 miles on it
-The ball bearing in the clutch actuator housing is still there
-The clutch push rod was once broken in two, but I've since replaced it with a new unbroken unit (a while ago).
-The clutch issue is fairly recent, and I can't think of any recent modifications made which might effect the functionality of my clutch...

Hope this sufficiently describes my issue, thanks in advance for any advice you can give me.

-Davis

[pangloss]

From that description it sounds like something is seriously binding in the release mechanism.
I'd be pulling the left fcover and checking the crazy spiral actuator that pushes the release rod. It's heavily loaded and can bind half way along the thread.

[davis96]

From that description it sounds like something is seriously binding in the release mechanism.
I'd be pulling the left cover and checking the crazy spiral actuator that pushes the release rod. It's heavily loaded and can bind half way along the thread.

That seems reasonable to me. Although I have pulled the cover many times recently, I must admit I have not physically checked the lifter mechanism to make sure it is moving smoothly. I'll have to pull the cover and check that out during my next "study break". Thanks pangloss

[vincentvega]

Maybe the push rod broke again? This is exactly what happened on my CB500 and this was the cause.

[iron_worker]

There is a lifter actuator (that's what I call it anyway). There is a female piece that is fixed to the case and a male piece that rides inside. They are either double or triple start threads to get a large amount of axial throw for a small amount of angular rotation.

I have seen first hand that the female piece in the case tends to crack and break and allow the male actuator piece to go into a bind as it spirals out. Most people think it's a clutch adjustment issue so they adjust the clutch out as far as they can to get the last bit of adjustment that they have left. This usually leads to a clutch that either does not release entirely or a clutch that does not engage entirely ... or sometimes both... which may be your case.

The pushrod that goes through the engine also tends to break into two pieces so check for that too. Some people, not knowing any better, have though that it was supposed to be two pieces!

Once you have the clutch actuator mechanism working properly you will want to check your clutch plates for wear and burning. If this clutch was run for some time like it is then you've probably burnt up your clutch pack.

IW

[davis96]

There is a lifter actuator (that's what I call it anyway). There is a female piece that is fixed to the case and a male piece that rides inside. They are either double or triple start threads to get a large amount of axial throw for a small amount of angular rotation.

I have seen first hand that the female piece in the case tends to crack and break and allow the male actuator piece to go into a bind as it spirals out. Most people think it's a clutch adjustment issue so they adjust the clutch out as far as they can to get the last bit of adjustment that they have left. This usually leads to a clutch that either does not release entirely or a clutch that does not engage entirely ... or sometimes both... which may be your case.

The pushrod that goes through the engine also tends to break into two pieces so check for that too. Some people, not knowing any better, have though that it was supposed to be two pieces!

Once you have the clutch actuator mechanism working properly you will want to check your clutch plates for wear and burning. If this clutch was run for some time like it is then you've probably burnt up your clutch pack.

IW

I will certainly check out my actuator today. A big question that comes to mind is why would this problem only present itself once the bike has gotten up to temperature? hmm, I guess we're stuck til I take a look under the side sprocket cover.

[iron_worker]

I think probably the clutch starts slipping and heating up and just gets worse as it builds more heat and slips more.

IW

[davis96]

Not much of an update, but I pulled the side cover and had a look around just to be sure that all the parts are there and working:

The pushrod is fully intact

I got the actuator thing pulled out and inspected it, the ball bearing is still there and the mechanism itself is not damaged, fully greased and working correctly. I also double check that the clutch cablle moved freely, and it did (smooth as silk).


Really hoping not to have to pull the left side clutch cover, but I can't think of any reason why it shouldn't be working correctly. Any more ideas are welcome!
-Davis

[iron_worker]

Pull the seal off the end of the female part. The cracks form underneath there.

Clean all the parts and get some fresh grease in there to see if that helps smooth it out.

IW

[davis96]

Pull the seal off the end of the female part. The cracks form underneath there.

Clean all the parts and get some fresh grease in there to see if that helps smooth it out.

IW

Well I'll be a son of a b!tch. Look what I found:




It is cracked, but could such a small crack really cause my problems even though there is that copper (?) seal on the end of it? Is replacement of the cracked part my only solution?... talk about hard to find for a decent price. On a related note, would the clutch adjuster from a cb500t work? these are cheaper and more plentiful, and appear (to me at least) to be the same part: *edit* I did a quick check on BikeBandit, and the clutch adjuster piece for the cb500t and the cb500k share the same part number, can anyone confirm this?

-Davis

[davis96]

I cleaned up al the adjuster parts, reinstalled them with fresh new lithium grease, and adjusted the clutch last night so I could see if it made any difference. Predictably it is pouring rain today. I'll keep you posted

[iron_worker]

I'm sorry to say I told you so but ... I told you so! lol  This is a very common problem on the 500s unfortunately.

Let us know if regreasing fixes 'er up or not. I have a feeling even that small crack is allowing actuator to cock off to the side just enough to not disengage/engage the clutch properly.

IW

[davis96]

The cleaning/lube job did the trick!