Topic: 1973 cb500 clutch/trans help

[dkirk]

I have been having some trouble finding answers through searching so I am posting some pictures hoping someone has experienced what I am finding.  I had a noise like a marble bouncing around in the clutch area.  So I pulled the cover off and did some investigating.  Looks as though the back of the clutch basket was rubbing a bolt head and part of the shifting mechanism.  There is a part that is installed that I can not find on the fiche, not sure if it is a spacer or what.  It was located on the shaft in the rear basket,  between the part that the plates and disks are on.  So, to clarify,  remove pressure plate, plates disks, snap ring and spacing washer,  remove plate and disk holder,  and when the rear basket is pulled off this piece is centered in the shaft hole with a flat end facing away from the trans.  All that being said I can tell the back of the basket is or can touch the mechanisms behind it.  I switched this piece so the flat end was facing the trans, on the back of the basket and slid the basket on.  NO rubbing.  Does anyone have knowledge of this?  I am attaching pictures of the damage,  and will take some more of the other parts. 

Thanks

[dkirk]

Ok, so I have more pictures. If anyone wants to see something specific please ask as I have taken a lot of pictures but I am not going to post all of them.  One other question I have is if any one knows what parts are #4 and #8 on the fiche? 

Take note of the "double disk" in two of the pictures.  It is not on the fiche either.

[bollingball]

Give it a little more time. I'm sure Dave500 or TT will shed some light on this. Maybe even PM Dave500. He is good about answering as well as TT. I have a 750 and they are different.

Ken

[dkirk]

Thanks bollingball,  I will wait to see what people have to say.  I am doing more research on other bikes and I am thinking that the PO may have tried to replace the old clutch with a 500T and they look to be different then the 500four.   

[SteveH]

So this is just based on my general knowledge and experience with 20-30 different clutch designs on old bikes over the years.....but....

I do not believe that there should ever be two friction plates w/o a clutch plate in between them.  That is one glaring issue.  the second is that your basket looked chewed up.  My gut feeling is the combination of the two is not fitting properly, thus causing your noise.
If I were you, I'd be looking for a new basket and new friction plates and clutch plates.

Can you see any part numbers on the basket and clutch drum ?  I wonder if they themselves are even correct....

[SteveH]

I almost wonder if the PO took the manual a little too litterly...If you look at the first image, it shows two friction plates together...But you need to read the next page to understand that it is one friction plate, one clutch plate.

[dkirk]

SteveH,  I was wondering the same thing,  but the picture that looks like the two are together is actually one disk.  They are riveted together.  I don't understand it either cause I have been looking through fiche and none of the 500k models have that.  I think that I am going to get a new basket, center, plates and disks.

[dave500]

that twin plate disc is from a later 550,your missing the washer/spacer that goes behind the basket,thatll let the basket move rearwards and foul the mechanism,rotate that sleeve the way it was and you need spacer #90455-374-000,maybe someones tried to use 550 parts?that schematic you show details both the 500 and 550 clutches,how many teeth does your baskets gear have?

[dkirk]

Dave500,  thanks for your help, but hopefully you can clarify some more things.  First which teeth am I counting,  the teeth that hold the disks in place or the teeth for the main shaft, or the teeth on the outer basket?

Second ,  do I need the spacer because it is a 550 clutch that is just a bit shorter then the 500,  or does the 500 require this spacer as well?

Third,  should I be concerned with the twin plate disc as you called it? 

Thanks again for your help
Doug

[dkirk]

One more question,  where might I find that spacer?  Is there someone that still sells them or do I have to find one off of another bike?

[dave500]

how  many  teeth  on  the baskets  gear?the large gear on the clutch,the count is different from the 500 and 550,youll need the 550s spacer if you have the 550 clutch basket,yours looks like a 550 basket as it has the one friction plate with wider tangs?david silvers dosent have one of those thrust washers,http://www.davidsilverspares.co.uk/parts/by-part-number/part_90455374000/

[dkirk]

63 teeth on the large gear on the basket.  I wonder if PO mixed and matched clutch pieces because the pressure plate looks like the 500 that is shown in the picture above, but you are saying the basket and the plates and disks look like a 550. 

[dave500]

its been changed,the 500 one has 64 teeth,you have 500 internals in the 550 basket,,that means you need that washer behind it and put that centre bushing the correct way again,your last friction plate has wider tangs than the others?

[dkirk]

No, all the tangs on the friction plates look to be the same to me.  So where do I go from here?

[dave500]

look at the tang slots in the basket,,,,the very outer one has a wider gap,,it may have the wrong last plate in it aswell from the 500?

[dkirk]

Yes the basket is slots are wider at the end which would allow for larger tangs on the very last one that would be against the pressure plate.

What do you think I should do from here?  Try and find the spacer of a used bike? Or try to switch back to the 500 basket? If switching back then I will have to switch the drive gear that the basket meshes with?

[dave500]

yes the basket and its driven gear are a pair together,find a used spacer and get the correct top clutch plate,someones done a half job conversion on it by the looks?

[dkirk]

Dave500, how many teeth should the driven gear have? I count 23 on mine.

[dave500]

check them again,should be 24 with the 550 basket,your basket looks to be swapped but not its mating primary gear,,the driven gear is on the basket,the primary drives the baskets gear,either,,find another 500 basket,or find a 550 primary gear and that thrust washer.

[dkirk]

So the 500 primary gear should have 23 teeth?

[dave500]

yes 23,ive never tried to swap baskets etc,,but having the wrong gear pair might cause a bad mis match of the way they mesh?i only have 550 stuff at the moment so i cant play experiments and see what fits/works/happens?im guessing your too small diameter primary gear will cause a shallower bite of the mesh?and the pitch might be odd?but then the larger clutch gear might take that up?or cause it to mesh too hard etc?next time i come across a 500 bottom end ill toy with that stuff,i think questions along these lines have been asked before?

id rather crunch numbers than gears!

[dkirk]

Ok, I counted and re-counted and I keep coming up with 23.  So I guess it was working but I am looking for a matched pair.  I have my eye on a 500 basket, and may go ahead and order new disks and plates. 

Thanks for all your help!

[dave500]

no worries,,you have to double check stuff like this,id like to see how the wrong basket and primary meshes?ive never tried it but its the first thing ill look at when i come across a 500,i only have 550 stuff on hand these days.