Author Topic: Clutch grabbing - it's either on or off - no gradual transition on release (Read 3112 times)

Master Ted · « **on:** March 07, 2007, 07:07:27 AM »

CB500K1. Clutch works great fully engaged or disengaged under all conditions but when hot smooth transition disappears when letting the lever out.

Parts book calls for square cut grooves on friction plates for CB500 but mine are slanted like CB550K1. I installed direction of slant as called for in manual so I think I got that right. I'm also confident in my adjustment per service manual and operation when cold (clutch is fine in all respects).

Any ideas? I've done a search and only see remarks on slipping which is no issue here.

kettlesd · « **Reply #1 on:** March 07, 2007, 11:13:22 AM »

Plates could be worn, warped, glazed or a combination of the three - have you mic-ed them or laid them on a glass plate to check for warpage?

TwoTired · « **Reply #2 on:** March 07, 2007, 11:30:52 AM »

Check the actuating rod that runs through the trans from left to right. Might have grooves or worn steps in that shaft.

There was a thread about this. And getting/making a replacement. Maybe a search could find it.

Cheers,

number13 · « **Reply #3 on:** March 07, 2007, 12:25:57 PM »

Ditto what TwoTired said, also be sure there is plenty
of grease in the lifter mechanism. Use the zerk fitting
on the left side case, next to the adjuster.

Jonesy · « **Reply #4 on:** March 07, 2007, 12:30:33 PM »

HondaMan also had some tips:

http://www.sohc4.us/forums/index.php?topic=7401.msg67252#msg67252

Master Ted · « **Reply #5 on:** March 07, 2007, 01:09:41 PM »

Quote from: TwoTired on March 07, 2007, 11:30:52 AM

Might have grooves in that shaft.

TT: There are two or three grooves machined into the actuating rod... not sure what you are refering to.

Dan: I read that piece and considered my friction plates were reversed as hondaman described for drag racing but I'm certain I got it right (I think

)

No13: I had her totally apart for cleaning and lube - the action is really quite nice.

Kettlesd: I think I better have a re-look. All looked good but I didn't get the plates down on a machined surface as part of exam. Warping may be my problem.

What about CB550K1 plates in this 500. I see both OEM and Barrett list different part nos. Has anyone mixed these years with any note worthy results?

RRRToolSolutions · « **Reply #6 on:** March 08, 2007, 04:27:01 AM »

I have a near mint 1972 CB500 also and the clutch action is really the only complaint I have about it. I bought it with 6,000 orignal miles and really did not want to take it apart, but the clutch would chatter during takeoff. When I say chatter, it just was not smooth and would grab/slip alternately when the clutch was being released making the bike unpleasant at stops. I finally took the clutch apart and replaced the steels and put in a new set of fibers. The clutch is better now, but not one of the better working models. It still grabs too quickly, does not have a smooth transition between stop and start. I really think there are some short comings in this bike's clutch release design. I've done a lot of clutches over the years and this one just doesn't have the smoothness. The CB750 is a work of art.

The Yamaha XS650/TX650 models are 10 time worse, so there is some good news in my message.....

Master Ted · « **Reply #7 on:** March 08, 2007, 06:37:12 AM »

Quote from: Ilbikes on March 08, 2007, 04:27:01 AM

I have a near mint 1972 CB500 also and the clutch action is really the only complaint I have about it. I bought it with 6,000 orignal miles and really did not want to take it apart, but the clutch would chatter during takeoff. When I say chatter, it just was not smooth and would grab/slip alternately when the clutch was being released making the bike unpleasant at stops. I finally took the clutch apart and replaced the steels and put in a new set of fibers. The clutch is better now, but not one of the better working models. It still grabs too quickly, does not have a smooth transition between stop and start. I really think there are some short comings in this bike's clutch release design. I've done a lot of clutches over the years and this one just doesn't have the smoothness. The CB750 is a work of art.

The Yamaha XS650/TX650 models are 10 time worse, so there is some good news in my message.....

Thanks for that... very, very useful. It's so good to know I am NOT alone in my misery.

TwoTired · « **Reply #8 on:** March 08, 2007, 10:24:03 AM »

Quote from: staphcar on March 07, 2007, 01:09:41 PM

Quote from: TwoTired on March 07, 2007, 11:30:52 AM
Might have grooves in that shaft.

TT: There are two or three grooves machined into the actuating rod... not sure what you are refering to.

Post a pic. However, I don't believe there are grooves machined into the rod by the factory. Whatever is making those grooves in your rod is in the trans and from undesireable wear from spinning parts. And, it has machined those grooves so deeply that it is hanging up the left/right motion of the rod during clutch actuation. The rod should have a smooth surface finish end to end. Others have found that rod broken at those grooves. Get a new rod, have a replacement made, or fill in those grooves to get your smooth transition back. I believe the ends of that rod are hardened, btw. This rod was a design issue solved when going to the 550 revision.

Cheers,

Master Ted · « **Reply #9 on:** March 08, 2007, 12:47:38 PM »

TT: I'll re-activate this thread down the line when I get it all disassembled. The weather is nice and I'm enjoying the bike way too much.

BTW, These grooves are actually rings cut so fine that it appears only a machine tool on a lathe could make them so perfect. I estimate the rings are only 1/16" wide and of simular debth. The rings are located on the rod inside the oil seals in the case area. I surmised the rings served a lubrication transfer purpose?

I'll post a pic when I get there...

TwoTired · « **Reply #10 on:** March 08, 2007, 01:45:43 PM »

The spinning parts in the trans cut/wear just like a lathe.

Order a new clutch lifter rod from David Silver spares, if they are still available. You can replace that part from the left cover in an hour, without dismantling the clutch. Unless that lifter rod breaks, then you have to poke it out or extract the remains from the clutch side.

When the clutch doesn't work smoothly, usually what follows is bent, worn, shift dogs, shifter drums, and broken, worn transmission parts. Then, if you can find the proper replacement parts, you have to pull the engine and split the lower cases.

Best of luck,

Master Ted · « **Reply #11 on:** March 08, 2007, 02:52:23 PM »

Quote from: TwoTired on March 08, 2007, 01:45:43 PM

The spinning parts in the trans cut/wear.

Spinning parts routinely cut rings into the actuating rod? Specifically, which spinning parts? What is wearing/wobbling so badly in the case so as to allow the lifter rod to get milled? Have you had this problem? I thought the rods break due to loose drive chains but have seen nothing else.

TwoTired · « **Reply #12 on:** March 08, 2007, 04:24:02 PM »

Read this thread:
http://www.sohc4.us/forums/index.php?topic=14273.msg140479#msg140479

Look at # 7 in this picture. Do you see any grooves machined into the actuating rod?

http://www.sohc4.us/forums/index.php?topic=14273.msg142207#msg142207

I don't know exactly what parts in the trans cause the wear. And, I'm not going to take my 500 apart now to find out, though I suspect it has a similar problem. If the bike ran, I'd fix it. But, the bike is a long term project and I have too many others ahead of it in the que.
Perhaps you'll be able to give us a full report on what it was in the future?

best of luck!

Master Ted · « **Reply #13 on:** March 19, 2007, 04:46:59 PM »

Quote from: TwoTired on March 08, 2007, 04:24:02 PM

Read this thread:
http://www.sohc4.us/forums/index.php?topic=14273.msg140479#msg140479

Look at # 7 in this picture. Do you see any grooves machined into the actuating rod?

http://www.sohc4.us/forums/index.php?topic=14273.msg142207#msg142207

I don't know exactly what parts in the trans cause the wear. And, I'm not going to take my 500 apart now to find out, though I suspect it has a similar problem. If the bike ran, I'd fix it. But, the bike is a long term project and I have too many others ahead of it in the que.
Perhaps you'll be able to give us a full report on what it was in the future?

TT, here is picture of clutch rod for CB500K1:

If interested you will find one on the block at ebay:
http://cgi.ebay.com/ebaymotors/NOS-Honda-Clutch-Rod-CB450-CL450-CB500-Four-CB500T_W0QQitemZ230105774570QQcategoryZ10066QQrdZ1QQcmdZViewItem#ebayphotohosting

Ted

TwoTired · « **Reply #14 on:** March 19, 2007, 06:16:38 PM »

Quote

TT, here is picture of clutch rod for CB500K1

Is that what your rod looks like?

I thought you were describing much deeper grooves than those.

Cheers,

Master Ted · « **Reply #15 on:** March 19, 2007, 07:35:57 PM »

My Words:

Quote from: staphcar on March 08, 2007, 12:47:38 PM

BTW, These grooves are actually rings cut so fine that it appears only a machine tool on a lathe could make them so perfect. I estimate the rings are only 1/16" wide and of similar depth. The rings are located on the rod inside the oil seals in the case area. I surmised the rings served a lubrication transfer purpose?

Your Imagination

Quote from: TwoTired on March 19, 2007, 06:16:38 PM

I thought you were describing much deeper grooves than those.

Part # 22850-323-000 in pic is listed for K0 thru K3 and earlier part #22850-292-020 is listed for K0 and superceded by the part with machined rings. I'm curious to know what the old K0 part looks like so if anyone has a pic it would be fun to see.

TwoTired · « **Reply #16 on:** March 19, 2007, 10:18:59 PM »

I hope you get your clutch problems worked out. It's pretty clear now that I won't be able to help you.

Have fun!

Master Ted · « **Reply #17 on:** March 20, 2007, 07:29:44 AM »

Hey! Don't go away mad. You made the comment in this and other threads regarding a problem with grooves on clutch rod as being a source of clutch performance problems. Since you are yet to explain what you mean I still have no idea what you are talking about. I'm simply pointing out the only grooves I know of are the machined rings. OK? It's just a process of understanding.

I'm inclined at this point to see the primary problem with the 500 clutch as emanating from the clutch basket assuming the drive chain remains adjusted (so as to not snap the clutch rod), actuator is lubricated and adjustment of the clutch maintained.

Presently, I'm pointed to Hondaman's analysis: steel plates with more than 10K miles are warped in nearly every instance. We shall see.....

peace.

Master Ted · « **Reply #18 on:** March 28, 2007, 08:40:14 AM »

Yesterday I worked out the grabby clutch problem and here is what I did that worked for me. It's hardly empirical but my results are good:

1) Best source of info on 500 clutch and illustrations of orientation of OEM slanted grooves of clutch disk is on page 40 of http://www.sohc4.us/index.php?option=com_remository&Itemid=80&func=fileinfo&id=7

2) Don't buy a new clutch rod unless yours is broken. Bryanj has prolly seen more 500s than anyone on this board and I subscribe to his notion that clutch rods break because of loose or broken drive chains that whip around and impact the clutch rod located immediately adjacent to front sprocket. A new rod I purchased from Bryan at a very, very fair price is identical to one on my bike. The rod is just a three piece affair where case hardend ends/tips are pressed onto a softer shaft and crimped to secure in place. I see no evidence that grooves or such can/do develop on clutch rod that impede it's operation in any fashion. My old rod had a very minor indentation where ball bearing in actuator contacts clutch rod... nothing more than tip and shaft end contacts any part other than oil seal.

3) I acquired a clutch basket on ebay from a 500K2 for absolute peanuts. I found not a single warped steel plate in either my K1 or the K2 basket nor were any of the friction discs warped. However, the stock friction disks in the K2 were considerably less worn than my K1 discs.

4) Pressure plates were not warped/scored in either clutch basket.

5) I assembled my clutch basket using steel plates, discs, springs, and pressure plate from the K2. I also changed oil moving from Honda branded 10-40 to Castro GTX 20-50.

Following adjustment clutch is operating as expected

hymodyne · « **Reply #19 on:** April 06, 2007, 01:44:09 PM »

I've been following this thread as I rebuild my 500K1. Running well, with the exception of consistent white smoke from 1&2 LH pipe.
My clutch doesn't work. I had replaced the clutch cable prior to this rebuild, and it worked fine until I decided to stop riding. during rebuild I used aftermarket friction (not the steel ones) replacement discs, taking care to replace them exactly as I removed the old ones. I cleaned and then regreased the worm grooved housing for the clutch actuator. at the lever, I get stiff but workable resistance from the cable and springs, but as soon as I put the bike in gear from neutral at an idle, it stops immediately.

is this a teardown issue? I've worked all week to get this thing running, only to have it run but not go

help!

hym

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Author Topic: Clutch grabbing - it's either on or off - no gradual transition on release (Read 3112 times)

kettlesd