Author Topic: Mysteries of the CB500 Clutch...REVEALED! (Read 52983 times)

Lavis500 · « **Reply #75 on:** April 25, 2011, 09:16:18 PM »

JT,

Look at the picture that 13 posted. This is where your clutch cable would attach to. When the clutch is disengaged (lever not pulled) the clutch lifter is in the the position shown in the left of the diagram. In this state, the 3 ball bearings sit in grooves, allowing the plates to be close to each other. When you pull the clutch lever, the plate that is on the left side of the mechanism turns. You are then brought to the position shown in the center of the diagram. Because one of the grooved plates has been rotated, the ball bearings force the plate on the left to be farther from the plate on the right. This pushes the plate on the right, pushing the clutch lifter rod and ultimately engaging the clutch. It is a seemingly simple design for a clutch lifter.

dave500 · « **Reply #76 on:** April 26, 2011, 02:48:06 AM »

Quote from: number13 on April 25, 2011, 01:32:24 PM

A later model Honda used a very similar design, but instead of a screw lifter it
used a 3 ball and ramp design like the image below.
I always thought that would be a simple and effective mod.
I have one somewhere in my parts pile. I'll try
to dig it out and get some pictures.

just out of interest the same mechanism is used on the old honda little auto clutch bikes,(ct70 etc)its linked to the gear shift rod and declutches the centrifical clutch as you shift gear.

foxrace4 · « **Reply #77 on:** May 06, 2011, 08:16:49 PM »

Alright guys, I am a noob to the site and I have clutch rod issues myself. I really don't know what to do but from the 4 pages of this thread, there are some really great info and ideas being tossed around. I want somebody to tell me exactly what I should do to locate the clutch rod and the lifter piece as well AND whats worked for anyone really well to date. I really appreciate everyone sharing their research and misfortunes to this crappy clutch dilemma....

AaronPossum · « **Reply #78 on:** May 11, 2011, 12:38:26 PM »

Hey guys, new to the site. Last year I bought a 72 CB500, and saved it from the junk heap, I've been through hell and back with this bike, carbs, coils, wiring, exhaust, seat fabrication, tires, rims, and damn near everything else. The final step in this project is the clutch which started going bad after I blew a clutch cable, (probably made the chain snap on the lifter rod in the harsh release.) My push rod is bent and torn to shreds, and it's very difficult to pull the clutch in, and even then doesn't always disengage the clutch fully. Tomorrow I'm going to get 3/8 drill rod, oil-harden it, draw the temper, and then put in on a lathe. My question is, the original rod has a kind of shoulder, in that it steps-down about an eighth of an inch from the alum center piece to the hardened steel clutch actuator towards the brake side of the bike. Should I carve that into my piece or keep it all at 3/8? Also, there are grooves on the original piece, two on the clutch side, and I think one or two on the brake side, it seems to help it "click-in" to place when inserted into the crank case, should I carve those too? The reason I ask is that they weren't mentioned earlier. Thanks guys, I really appreciate it, one more step and my first motorcycle is DONE!

mjstone · « **Reply #79 on:** August 08, 2011, 05:36:04 PM »

I finally got my clutch cover off and replaced my clutch push rod. Man, what a change! This bike shifts so smooth now I'm absolutely amazed! Even my father in law, the PO, took it out for a ride and said that the rod must have been broken for a long time.

MJ

Danno · « **Reply #80 on:** August 08, 2011, 06:03:48 PM »

Don't be too hard on yourself #13 after all it worked did it not and from what i could tell it worked well and you never know unless you tested it long term it may have outdone the honda engineers because after all their piece was broke you never know yours may have gone the distance I know there is something to be said for origional but these clutch pins all break and who is to say yours would have I am an engineer and I am always trying to do things a better way if they break you would be surprised the number of parts I have made or redesigned over the years the way I look at it is if it broke before its life was due then it is wrong and was engineered wrong look at all the things that were tried to stop the tappet shafts from rotating on 550 and 750 heads are they wrong because they are not stock the only way to tell is did it work and how long did it last
from my point of view nice bit of engineering

Danno · « **Reply #81 on:** August 08, 2011, 08:13:12 PM »

that is not a bad idea 13 but i would think that some ramps machined about 3/32 pitch would do the same thing but how to hold them together over the rod
the ball trick is sweet but I would wonder if the constant vigors of actuating the clutch might do it in

Annika · « **Reply #82 on:** October 11, 2011, 02:25:43 PM »

I'm looking to replace several of these parts myself-- #5, #7 and potentially #9 but my sources tell me the lifter rod is no longer being built and the adjuster is on back order with no release date. (My source being servicehonda.com)

Any suggestions where else I might find these guys?

crazypj · « **Reply #83 on:** October 11, 2011, 09:26:24 PM »

Use 'drill rod' or 'Silver steel' and make one.
I forget size, 6 or 7mm diameter?

Kermit · « **Reply #84 on:** October 17, 2011, 08:25:31 PM »

Quote from: plippo on April 25, 2011, 02:46:57 PM

In case some of you interested in the clutch rod for the 500, a friend of mine in Italy has manufactured some very high quality repro, with C40 Steel, and heat treatments.
In italy is impossible to find the part, so he has commissioned some very good CNC made...

see auction.

http://cgi.ebay.it/ws/eBayISAPI.dll?ViewItem&item=360194715415

I know this is an old thread, but has anyone in the states had this made?
Also i'm trying to locate a new seal for it, anyone know where to get one or what schematic its on?

dave500 · « **Reply #85 on:** October 17, 2011, 10:43:01 PM »

clutch rod seal # 91203-292-005

Kermit · « **Reply #86 on:** October 18, 2011, 09:48:11 AM »

Thanks, i'm got it in my wish list now. I've just got to find someone to make me a new rod now.

Lorbaez · « **Reply #87 on:** October 21, 2011, 01:49:09 PM »

Hi guys,

Just for your reference: Since rod is not available as spare part anymore, I used one from a CBR1000RR 04-07ym. Diameter is 0.5 smaller and it is around 20mm longer, Diameter difference is not a problem and lengh can be adjusted.
It works properly on my CB500K2 1975

Annika · « **Reply #88 on:** October 21, 2011, 11:37:02 PM »

Thanks for the tips !

Anghil · « **Reply #89 on:** February 23, 2012, 10:55:24 AM »

Quote from: number13 on October 03, 2006, 06:46:04 PM

2) WORN CLUTCH RODS
Another fatal problem I soon discovered was the fact that my cable
cinch near the lifter was crashing into the sprocket every time I used the clutch.
It was obvious that the clutch rods had shortened with years of use.
This shortening of the clutch rods and consequent over-adjusting of the
lifter is probably why all those lifters I found at the junkyard were cracked and had
worn out cable cinches. It is a domino effect, the rods shorten, the clutch lifter
gets over adjusted to compensate, the compensation makes the cable cinch
crash into the sprocket and the crashing causes the cracking of the lifter sleeve.

I ran into this same problem. I got a hold of a brand new lifter, but it's catching along the same point on the chain wearing it down. I've tried adjusting the cable, but to no avail. Am I missing a step or is the clutch adjuster just too tight?

mjstone · « **Reply #90 on:** February 23, 2012, 04:29:36 PM »

Did you make sure your ball bearing is in there? It will add to the total length of the clutch rod assembly.

MJ

dave500 · « **Reply #91 on:** February 23, 2012, 09:14:05 PM »

good detail mjstone,if the ball isnt there it wont de clutch fully,,itll drag and be impossible to adjust correctly,the adjustment cant cover that amount of travel.

Anghil · « **Reply #92 on:** February 25, 2012, 12:26:18 PM »

I do have the ball bearing. It seems like it's a length issue. When I have the clutch adjuster completely loose, meaning it won't disengage the clutch when I pull the lever, it doesn't rub against the chain. However, when it's properly, or what I THINK is properly, adjusted it rubs against the chain. However, looking at the left crank case diagram, I realised I don't have part #2 item: 11353323000 I'm assuming this may be a problem =O

dave500 · « **Reply #93 on:** February 25, 2012, 01:01:14 PM »

you can run with that guard missing,have you withdrawn the rod from the case?,is it broken in two?is the rod the correct way around?the domed end goes into the case and clutch,the sort of flattish end rides on the ball in the lifter mechanism,if its the wrong way round the dome will skate of the ball and the rod will travel askew slightly,is the front sprocket 17 teeth?

Anghil · « **Reply #94 on:** February 26, 2012, 08:56:27 PM »

Alright, now I really feel like an idiot. I was previously unable to withdraw the rod from the left crank case, so I assumed it was in one piece. I removed the right case today and found the rod in 2 pieces, along with a small amount of metal shavings. Thanks for the help. -

dave500 · « **Reply #95 on:** February 26, 2012, 09:52:20 PM »

solved,they seem to break those rods,heres a handy link.
http://forums.sohc4.net/index.php?topic=369.msg949314#msg949314

Anghil · « **Reply #96 on:** February 27, 2012, 03:00:00 PM »

Thanks! I found a couple places that still have these for 32 and 35 bucks. Where should I post their info?

crazypj · « **Reply #97 on:** February 27, 2012, 10:44:00 PM »

You could make 3 for that price
http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=619-1662&PMPXNO=16719418

http://www.use-enco.com/CGI/INPDFF?PMPAGE=781&PMITEM=619-1662

Anghil · « **Reply #98 on:** March 03, 2012, 11:57:37 PM »

Unfortunately I neither have the skills nor the equipment to make my own, but it sounds like you could make a fair bit of money selling copies that you make...

Buzzard Toast · « **Reply #99 on:** June 08, 2012, 09:03:14 AM »

New to the SOHC forum ... and this is a fitting first post since I have struggled with this issue to the point of max frustration. I appreciate all the detailed info. on this issue. But despite the the fact that I have identical symptoms to what you described, all my parts check out. Lifter rod is intact and straight ... adjuster is solid and well lubed. Cable is smooth and routed well. The next thing I was going to do is drain the oil and pull the clutch cover and inspect the basket. Any suggestions .... ?

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Author Topic: Mysteries of the CB500 Clutch...REVEALED! (Read 52983 times)

foxrace4

AaronPossum

Annika

Annika