Author Topic: 500 4th gear AWOL  (Read 3682 times)

Offline Tomb

  • SOHC Pro
  • Posts: 658
    • View Profile
500 4th gear AWOL
« on: February 16, 2012, 06:15:56 PM »
Anyone got any info/ideas please.

Riding to work a few weeks ago I lost 4th gear, I've been too busy to look at the bike but thought I'd ask before making plans to delve into the box. I'm just coming to the end of another rebuild with parts everywhere so didn't have time or space to do the Honda and have been using it for the work run by short-shifting through 4th.

It appears to go into gear, so the selector mechanism seems to work, but doesn't drive, I get rattling like its trying to engage if I try to drive through 4th and when this rattling happens I get a pulsing on the clutch lever mimmicking the noise, as if the dogs are worn and its trying to work but pushing the clutch shaft slightly. Is this a known fault like 2nd gear on early Yamahahahas, or is it just old age and use showing up. I have a 550 donor bike that may donate its engine to keep me OTR for now.

Any ideas from you experts would be welcome.





BTW, the rebuild I'm busy with included fixing the 2nd gear on the Yamahaha ::)
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's

Offline LesterPiglet

  • SOHC Pro
  • Posts: 986
  • 1977 CB550F2
    • View Profile
Re: 500 4th gear AWOL
« Reply #1 on: February 17, 2012, 12:12:13 AM »
Dogs are probably broken off. Time for a strip. You could probably see the damaged component by removing the sump.
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Set/sit. Bought/brought FFS. Bloody Americans.


Les Ross. Certified by a Professional

Offline Bryanj

  • Grogu
  • *
  • Posts: 10695
    • View Profile
Re: 500 4th gear AWOL
« Reply #2 on: February 17, 2012, 07:40:16 AM »
There is no one gear over any other that breaks but all can if abused in the past, i have seen dogs sheared off before now.

Gears and selectors are getting more and more difficult to find and 550 ones don't fit (maybe SOME gears before i get jumped on!! but a lot dont)

Offline LesterPiglet

  • SOHC Pro
  • Posts: 986
  • 1977 CB550F2
    • View Profile
Re: 500 4th gear AWOL
« Reply #3 on: February 17, 2012, 09:30:43 AM »
I have the 3rd from a 500 in my 550.  Just to clarify.  Sorry Bryanj.   :P
« Last Edit: February 17, 2012, 09:32:33 AM by LesterPiglet »
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Set/sit. Bought/brought FFS. Bloody Americans.


Les Ross. Certified by a Professional

Offline Tomb

  • SOHC Pro
  • Posts: 658
    • View Profile
Re: 500 4th gear AWOL
« Reply #4 on: February 17, 2012, 10:31:57 AM »
Thanks Lester and Brian. My brother has a 500 bottom end lurking about somewhere, I'll try and scrounge it for the gears.

I was hoping to plonk the 550 engine I have in whole.

Many thanks
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's

Offline z1100r

  • SOHC Member
  • Posts: 233
    • View Profile
    • Home Pages
Re: 500 4th gear AWOL
« Reply #5 on: February 17, 2012, 11:07:17 AM »
There is no one gear over any other that breaks but all can if abused in the past, i have seen dogs sheared off before now.

Gears and selectors are getting more and more difficult to find and 550 ones don't fit (maybe SOME gears before i get jumped on!! but a lot dont)



  Sorry Bryan I have to disagree. There is a gear that is particulary weak on the 550.....its 3rd if I remember right, Honda later modified it by blanking off the dog slots at one end. I broke 2 3rd gears when racing, and finally fixed the problem when our local Honda agent showed me a service bulletin and produced the more solid 3rd gear.
   My race gearbox (the one thats in the restored bike as it stands) was constructed of mix and match  500/550 parts with the beefy 3rd included. (I agree there are some that are not interchangeable).

  As a race tuned 600 my Honda's original 3rd gear was nearly as bad as all 6 are in the 'chocolate' Suzuki RG500.

Offline Bryanj

  • Grogu
  • *
  • Posts: 10695
    • View Profile
Re: 500 4th gear AWOL
« Reply #6 on: February 18, 2012, 02:24:10 PM »
OK I admit to buiding a box using 500/550/650 gears but as i said ONLY SOME fit and its PItheA working out which!

Offline matthewmosse

  • SOHC Master
  • Posts: 2161
    • View Profile
Re: 500 4th gear AWOL
« Reply #7 on: February 18, 2012, 10:26:37 PM »
Just as well. I have about 5 mixed gearboxes off 500/550s in boxes. I know I've built a hybrid box and clutch which was a pita as i got the gears right but the shaft is different and cases and cluch didnt suit my available bits so it was a bit of a build up and strip down twice thing
Got a 500/4 with rust and a sidecar and loadsa bits. nice and original and been round the clock

Offline Bryanj

  • Grogu
  • *
  • Posts: 10695
    • View Profile
Re: 500 4th gear AWOL
« Reply #8 on: February 19, 2012, 04:05:48 PM »
Even worse is the fact that Honda at sometime changed the tooth profile so gears frequently have to go in mating pairs

Offline Beemer634

  • Newbie
  • Posts: 44
    • View Profile
Re: 500 4th gear AWOL
« Reply #9 on: February 29, 2012, 10:34:08 PM »
Hi

I had the same problem on my 550 last year, the guys here were right when they said the dogs can break off, thats what my problem was. Bit of a pain having to pull the motor out but reasonably easy to fix though. It is now a joy to have them all back!

Rick
'77 BMW R100RS
'77 400/4
'76 750/4
'72 500/4

Offline jcknapp

  • Newbie
  • Posts: 26
    • View Profile
Re: 500 4th gear AWOL
« Reply #10 on: March 01, 2012, 04:39:49 AM »
I had this problem happen to me a year ago on my 500. I think you are talking about a 500 correct? What happened to mine was the needle bearing broke on the inside sending steel in my clutch basket and everywhere else which caused the clutch to rattle. You could still get it into gear but it was destroying everything. I took off the basket and everything, looked around and saw the bearing that was shattered. This little guy is notorious for overheating because of the poor oil circulation by it which was later improved with the 550 engine. So hopefully its not this, because if it is you got to drop the engine, pull it apart, replace the little guy (inexpensive) and completely clean out the transmission and clutch box. Otherwise if there are little pieces of metal in that you will most likely be paying for it later.  This is just a hunch. Maybe Im completely wrong with your problem.

TON UP!!!

Offline Tomb

  • SOHC Pro
  • Posts: 658
    • View Profile
Re: 500 4th gear AWOL
« Reply #11 on: March 01, 2012, 07:29:44 AM »
I think you are talking about a 500 correct?
Yup

Thanks for the info lads, I was planning a strip down anyway so its not a huge job. I've just undercut the gearbox dogs on my Yamahahaha and just taxed it (online, yippee) so the little Honda can have a well deserved break. I have a donor 550 engine which I'd like to try out so ideal opportunity

I suspect the dogs coz everything else works just fine and I've been using the bike for the work run for that last month+ still
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal