Topic: CB550 transmission trouble - 2nd and 3rd

[Franky]

Hi guys

My '77 CB550 has started to develop transmission/clutch issues. I've had the bike since last winter and it's only in the last few weeks the below has started to occur.  I've read a lot of post of transmissions turning clunky and wierd when engine warms up, but none the other way around.

When cold, I'm having issues with 2nd and 3rd gear:

2nd
When I shift from 1st gear, sometimes it hardly makes it to the 2nd. The neutral lifght stays on and it falls back down into neutral. When it does this the RPM shoot up. I'm usually quick to engage the clutch and another try at upshifting gets it into the 2nd gear.

3rd
This is the biggest part of the problem and will sometimes, although rarely, return at random when the engine is warm/hot.
It simply won't let me shift from 2nd to 3rd. When i try, theres just... nothing! The feeling is sort of like if you're shifting down when in 1st gear. I usually ride along for 5-10 mins and after a many up-and downshift the 3rd gear is suddently there. If i ride along for a bit and come to a stop shortly thereafter, the whole thing repeats, although it takes somewhat less tries to make it shift.
If I ride for somewhat longer, it behaves nicely and the 3rd gear is there without a hint of the above. The shifting is actually quite smooth when I have been riding for 20 min or more - both up and down. There's never a problem finding 3rd when coming down from 4th.   

More info:
- Pulling the clutch lever takes some effort compared to other bikes. Nothing crazy, just a bit more effort. Always been like that.
- I use 10-w40 motorcycle specific mineral oil.
- When getting it from the PO, it was somewhat hard to find neutral, which improved greatly after a little adjusting.
- Overall, one needs to be firm when shifting. There isn't any resistance, but if one only does a casual, 'weak' shift, it'll sometimes fall into a false neutral. This happens very rarely.

[Scott S]

 Sounds simple, but I'd start with a full clutch adjustment if you haven't done so already. It's amazing what some P.O.'s and "mechanics" do before you owned the bike.

[Franky]

The past few days I've adjusted the clutch like mad, and no matter what I do, the shifting doesn't seem to improve. I've followed instructions from this site and the CB550 owners manual.

I don't know what it is supposed to be like, but it seems wrong, that I have to turn the locknut-screw as far as it can physically go (clockwise) to make the alignment marks align? When having aligned the marks, there doesn't seem to be much 'left to pull'. The lower adjustment screws on the cable have to be adjusted to the furthest extreme, meaning the cable is as long as possible.  Is this a sign of a worn out clutch? Or only certain parts of the clutch?

I know the PO and a reputable mechanic has done a good rebuild of the engine - runs great - but I think the clutch is the same 30+ years old one.

I think I'll get a new cable + clutch kit (http://www.davidsilverspares.co.uk/CB550K-1978-USA/part_145107/ OR http://www.cmsnl.com/products/clutch_00000kit0313/). Which kit to get, I guess  depends on whether my steel plates are warped or not. 

Is it overkill to replace the clutch? Is it likely that it will solve my shifting problems?

[Scott S]

 Is the clutch cable aftermarket or genuine Honda. I had terrible luck with aftermarket cables on my CB500. The clutch cable was firm and stiff and the throttle cable was too long. I ran out of adjustment just like you did with your clutch cable. Genuine Honda cables fixed both of those problems.

 If the clutch is original, it's probably time to replace at least the friction discs. Time to pull the basket and isnpect/measure the discs and plates.

[Scott S]

 And when you pull the clutch cover, actuate it with the lever before you disassemble anything. See if you see anything out of whack or abnormal looking in the actuation.

[Franky]

Yes, I figure I'll need to take the thing apart. I just like to have whatever spares I need ready before I start taking things apart :-)

Not sure if the cable is genuine, but I'll buy a Honda one for sure. With the 'out of adjustment' I meant the adjustment screw on the bottom of the case - the one with the lock-bolt. But as mentioned, this also causes me to having to adjust the cable to its longest extreme to make it pull the arm (with the alignment mark) sufficiently upwards.

[Rgconner]

Replace the O rings on the oil pump.

Read HondaMan's instructions on hoW to add more oil holes to the clutch.

Check for a broken shifter rod.

Try using heavier oil.

[Franky]

Thanks for the advice - all are appreciated.

Any of you know which one of these kits I should get. Notice that the steel discs are different. Both are listed at cmsnl.com to fit a CB550 K3:

[dave500]

have you got your clutch apart?has yours got a funny sort of two rivetted together steel disc in the middle?if it has you want the kit with only five steel discs,the clutch rod isnt like the 500 one that can break,its a short little ball ended thing.

[Franky]

Finally found some time to take it apart.

Dave: Yes, it has the rivetted together steel disc, so I know that kit #2 is the one to get.

I'm not sure whether I should get a new kit though. The steel plates didn't seem warped (put them on a piece of glass and tested with feeler gauge). Both the springs and the plates were within the specs in the manual. Beyond that, I don't know how bad plates and friction discs look like - maybe you guys can tell from the images?

Also found out, that the shiftingarm (the regular one on the left side) has too much play, which inhibits shifting somewhat. As you can see in the image, the little geararm behind the clutch has scratched the engine a bit. Doesn't seem like a bit deal to me though?

Thanks for your help and for putting up with newbie franky :-)

[dave500]

if your clutch isnt actually slipping under hard accelleration its probably ok,save your money,look behind at the shifter detent assembly,there might be a spring dislodged or some thing,put it on the centre stand and go through all the gears selecting first through fifth and back again watching any action of the mechanism you can,you might need to drop the pan and have a look up at the forks and try to see if they are worn down?try and deglaze the steel discs,i use a little sand blaster,you can use emery paper or similar,note the first clutch friction disc is slightly larger than the rest,the steel discs are stamped and you can see or feel the sharp edge on one side,stack them in the same direction when you put it back together with the sharp edge facing out,,not terribly important but good attention to detail.

[dave500]

is that curved drum locater bent or straight?it also locates the rod supporting two shifter forks.,they can bend and let the drum move sideways a little.

[Franky]

Well it turned out, that the darn gearchanger was hitting the generator cover during upshifts. This was the main cause of the bad 2nd and 3rd gear shifting.  Jeeez...

However, I still have problems adjusting the clutch and as mentioned above, when I align the marks (3 on image) the lever can't go any further upwards when pulling the clutch lever. Is it normal that the Clutch Adjuster Screw (2 on the image) has to go as far as it can go clockwise (and hit a stop) before the alignment is reached?

After having it apart, it drags more than before (making shifting harder and clunkier). I'm positive I put it back together properly and the only thing I did while in there was deglazing the discs with fine sand paper (or emery cloth) and carefully filing the fingers of the clutch basket (mild indents). Could I have been too heavyhanded and caused the extra drag?

Dave: The clutch isn't slipping under accelleration and the drumlocator seemed fine and not bent.  Thanks for your detailed tips on deglazing, etc. I picked some of it up in this great forum already and made sure to do it all. (PS: Heavy fall rain is upon Denmark and I envy your sunny, non-snowy climate! Must be great for year-round riding)

[dave500]

to adjust the clutch for a little more bite,slacken the cable at the handle bar end,then with the case locknut adjuster turn the centre screw inwards or clockwise a little,re adjust the cable and try it again,,those two dots on the case and lever dont really work well someimtes on a used but still quite ok clutch.,,yeah we have great all year riding here,bring your bike and come for a ride!

[Scott S]

 What's the deal with the riveted plate? I'm not familiar with that....

[Franky]

That riveted plate is basically just two steeldiscs stuck together with a little space in between. It sat in the middle of all the plates and discs.

Dave: I'll give the adjustment another try asap!

[dave500]

the twin plate is the later "improvement"the older type with the plain plate is fine,,its to stop shudder under hard clutch abuse,like a novice on a steep hill start who might dump/drop/release the clutch lever suddenly at revs.