Topic: HELP!!! Transmission/Clutch/Shifting ISSUES - and im a newb to these bikes

[jcorrill]

Hello everyone, i am new to the forum as well to the vintage motorcycle scene (however i have been around dirt bikes/ATVs since i was little - even racing them at one point in my life).  I am in the process of restoring/building my 1978 CB550.  So the goal is to get it running pristinely as well as give it that cafe look, and im juggling both of them at the same time, while trying to enjoy it (riding) as much as possible.

The background to my situation - the PO put new cables on, which is awesome, but also left the clutch out of wack.  My mechanic buddy adjusted it the best he could on the handle bars, but said he would need to dive in deeper to get it fully corrected.  However, he is a full time mechanic, and a musician, so he doesn't really have time to help me out - and most shops this time of year are not only expensive as  , but also backed up several weeks.  Therefore, i am tempted to do the work myself.  Plus, half the enjoyment with these vintage bikes is figuring out the problem and fixing it.  Although i do not have much mechanical experience, I want to learn to work on these bad boys, because it is my new obsession lol.  I am pretty quick at learning, and have been doing a good amount of research (however i am not great with terminology - for lack of a better term... newb)

With that being said, the issue at hand, is what i believe to be either transmission or clutch, which is where you guys come in handy.  My bike becomes very difficult to put in neutral while i am stopped, although while rolling or turned off, it goes in just fine.  From my understanding, that is just an issue with the clutch.  Sometimes i also, while switching gears, land in false neutrals (mainly between 2/3 and 4/5), which from what i've read is a pretty common issue with vintage Hondas.  Recently though, it has been falling out of gear (riding in second, then suddenly drops to neutral), or even shifting to the wrong gear (ie - when i shift up, sometimes it feels like it doesnt shift or possible even shifts down, then eventually clicks into gear). 

I have read a post in the past (i think it was on this forum, but it may have been another), where a guy was having a similar problem, and he opened her up, and it was simply the spring that was attached to the shifting lever.  It had worn out, and eventually broke.  HE then made a new one himself, and according to the post, never had issues with it again. 

So my question is... is this a transmission issue, or a clutch issue or both.  I found a good deal on a whole transmission set, and was thinking that i should just go a head and pick it up.  But if this is not the issue then i would rather just grab the parts necessary. 


Any advice would be greatly appreciated - i need help figuring out what parts to get so i can begin the process of fixing it. Thanks for your time, and i hope to hear back from someone with more knowledge than i possess. 

Please enlighten me!!!

[calj737]

First, welcome. If you don't already have a good manual, here's a link to one on this forum: http://www.sohc4.net/cb550books/
And here's a comprehensive parts fiche: http://www.cmsnl.com/honda-cb550k-1978-usa_model7222/partslist/

You can use these links to aide you in understanding the components as well as evaluate anything you take apart, to insure it's complete and correct (not molested by a previous owner).

Your symptoms would make me think of both an improperly adjusted clutch (slipping and disengaging from gear) but could also be early signs of wear in the transmission. First order of business would be to determine that the clutch is properly adjusted, review the manual for the pros on that.

Many members swear that certain oils (not looking to start a debate) have different influences on the performance of the clutch. I have no evidence, but it may be worth a shot. I've seen those who feel strongly about certain oils recommend Rotella brand 15w-40. Hell, it may be worth a shot after the adjustment.

Opening the engine case to examine the tranny is a significant job. You should expect to be out of riding for many weeks should that be necessary. And it may be a prohibitive job for someone new to working on bikes. Unlike a car, the transmission is internal to the engine case and shares the oil with the engine and clutch.

If the cable adjustment didn't solve the problem, my next step would be to remove the clutch cover, right side, in front of kick starter. It houses oil, so drain the engine oil first. Examine the clutch friction discs and steel plates (these alternate and have an install sequence. See the parts fiche and manual for that). If it's in need of replacement, do so. Trying to rule out as many easy parts before digging into transmission.

If those things don't solve your problem, gonna be a drag but you'll need to pull the engine and open it up to deal with worn transmission components. Let's hope that's not the issue.

The "search" function at the top of the page can be very helpful if identifying threads where members have dealt with, documented and answered many questions you will have. Always look around a bit, so you can get answers promptly when you need it. If you can't find what you need, or need further clarification, just post up a question and some knowledgable sort will be all too happy to lend a helpful word.

Exciting owning a piece of history, huh? Tons of fun, great hobby, and many great people on here all too happy to help you out!

Keep posting your progress or questions on the clutch.

[jcorrill]

thanks for the speedy reply - so i just finished adjusting the clutch, and it already seems to be running better.  However, it still seemed a bit difficult to get into neutral from first (while running), and it also slipped out of gear once.  This could also be because my adjustments are not perfect.  Once i rule out the fact that adjusting the clutch is not the issue, which my gut tells me its not going to be that easy, what should i be looking for once i remove the cover?  IS there where i should serf the forum?

[jcorrill]

I read a thread once where a guy had similar symptoms to mine, and he opened her up and he replaced the shift return spring, and it was fixed.

I forgot to add one symptom, my shifter sometimes gets stuck when i down shift, and i have to manually bring it back up. 

[calj737]

The first things to look for if you remove the cover, is to compare everything inside to the parts fiche. Always make certain you have all the parts, and that they appear to be in proper condition and proper orientation. You'd be surprised how many band aids you might find from previous owners.

Regarding the clutch discs, remove them and take several thickness measurements on each friction disc, at differing locations. Note the thickness. In the manual, there is a service limit minimum thickness. If you're out of spec, replace. The steel plates, lay them on a piece of glass or other extremely flat surface and evaluate for flatness. These can become warped over time. Replace 1, replace all. The clutch springs, penetrate the discs and squeeze the clutch together when releasing the lever. Measure these for compression and rebound. All these measurements are in the manual for reference.

If you discover undue wear of the friction discs, I'd also drop the oil pan. This might be an extreme task to some, however, it's not unlikely that some of the friction material has come loose and now flows through your engine and is waiting to clog up the oil passages. This latter service is not likely necessary, but anytime you replace a clutch, it's a good "ounce of prevention". You'll need a new oil pan gasket and clutch cover gasket if you undertake these services.

[jcorrill]

Cal - thanks for the advice, thats exactly what i was looking for man.

[jcorrill]

Progress:  So i had a buddy (mechanic) adjust my clutch, since my adjustments helped, but didn't solve the problem.  It is riding better, but i currently have synthetic oil running in it, and he said to switch that out and it will help as well.

One thing that he brought up that was a little concerning, was that the screw that goes into the cover, seemed to be a little crooked.  The groove in which the flat head fits into, was closer to the lock nut on one end than it was the other.  HE too had trouble dialing it in to perfection, which leads me to believe that there are internal issues going on.  I will change out the oil, see how it rides, then get back to you on a further update.  Thanks again for the response.

Jake

[calj737]

It's possible that the adjuster is misaligned or tweaked. If your final changes don't significantly improve operation, remove the clutch cover and examine it. Those parts are available either used or new and they're not very expensive.

[dave500]

the slot in those screws snaps off some times,thatll make it look crooked.