The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Lucky_Lou on September 25, 2016, 09:52:48 AM

Title: Gearbox issue..
Post by: Lucky_Lou on September 25, 2016, 09:52:48 AM
Just back from a ride out and had a problem with 3rd gear, going up the gears no issues going down the gears and I keep missing 3rd ? clutch seems ok any thoughts.
Lou
Title: Re: Gearbox issue..
Post by: Bob_Roller on September 25, 2016, 12:06:42 PM
I had issues when I had the transmission from my '81 R65 overhauled .

I could up shift through all gears, but had all kind of problems trying to downshift .

Shifter shaft seal was damaged during installation at overhaul and was preventing me from down shifting .

Not exactly the situation you have, but this came to mind .

Title: Re: Gearbox issue..
Post by: Lucky_Lou on September 25, 2016, 02:59:29 PM
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Shifter shaft seal was damaged during installation at overhaul and was preventing me from down shifting .
As far as I am aware the gearbox has never been stripped down, the bike has only 38k miles, i will drop the oil and see if there is anything unusual i got an odd metallic sound on tickover at one point ( bike was fully warmed up having done about 30 miles) which sounded like it was from the Gearbox/tranny it stopped after about another 10 miles.
Lou
Title: Re: Gearbox issue..
Post by: clonmore1 on September 25, 2016, 04:11:59 PM
Hope it's nothing too serious Lou
Title: Re: Gearbox issue..
Post by: Lucky_Lou on September 25, 2016, 04:22:01 PM
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Hope it's nothing too serious Lou
Oddly enough i was in Honley at the Shell garage when i noticed the noise, from there a quick blast to Castle hill then home.
Lou
Title: Re: Gearbox issue..
Post by: Tony Smith on September 25, 2016, 04:26:51 PM
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Just back from a ride out and had a problem with 3rd gear, going up the gears no issues going down the gears and I keep missing 3rd ? clutch seems ok any thoughts.
Lou

Can you get it into 3rd at all with a bit of fiddling or is 3rd completely "missing"?


If can't select 3rd going up, but the box goes into 3rd coming down - if you do a sharp accelerate/decelerate does it stay in 3rd or pop out of gear?

If it does go into 3rd on downshift and stays in gear after that then you have a shift problem that is likely the shift plate. If it will not stay in 3rd on downshift but selects 3rd OK on downshift you probably have a missing dog on the gear (which might explain the metallic noise you heard earlier).

A damaged shift fork could cause some of your problem, but 3rd is not generally a gear that gets abused too much so I really think it is unlikely.


If it doesn't go into 3rd on downshift then disregard my comments above and start saving for a rebuild - if there is no 3rd engagement at all it could be all the tings above and a few more things as well and the only way to know will be to pull it apart and examine it...

Do you have the skills/confidence to do a rebuild yourself? If not I have one final bit of advice - have yours rebuilt and do not purchase an exchange gearbox unless the exchange box comes with a VERY long warranty.
Title: Re: Gearbox issue..
Post by: mrclubike on September 25, 2016, 10:00:25 PM
I thought a bit of a knock sound is normal when in neutral at tick over and then stops when the clutch is pulled in.
Isn't it just gear back lash  
I find I have the most false neutrals when  trying to go into 3rd or 4th gear
Title: Re: Gearbox issue..
Post by: Lucky_Lou on September 26, 2016, 03:38:47 AM
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Can you get it into 3rd at all with a bit of fiddling or is 3rd completely "missing"?

If can't select 3rd going up, but the box goes into 3rd coming down - if you do a sharp accelerate/decelerate does it stay in 3rd or pop out of gear?

There is no problem going up through the gears and it does not "pop" out changing down it feels like its go into gear and the lever comes to a solid stop but its in a false neutral, I tried varying the revs as I changed down but that made no difference, after several goes  going back up and down it would find it ? I am a competent engineer and have rebuilt gearboxes on cars back in the day when I could only afford bangers.
 Are any special tools needed for a strip down on this ?
Lou
Title: Re: Gearbox issue..
Post by: clonmore1 on September 26, 2016, 10:48:11 AM
Next time you are in Honley, shout if I am either at home or in the office (village centre), call in for a brew/chat, kettles always on...
Title: Re: Gearbox issue..
Post by: SoloLobo on September 26, 2016, 11:12:59 AM
Start by making sure that you have adjusted the cable per the factory instructions.

Adjusting the freeplay, or having the wrong distance from the arm to case can cause shifting issues
Title: Re: Gearbox issue..
Post by: Tony Smith on September 26, 2016, 03:21:51 PM
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There is no problem going up through the gears and it does not "pop" out changing down it feels like its go into gear and the lever comes to a solid stop but its in a false neutral

 Are any special tools needed for a strip down on this ?
Lou

That is a bit weird, in fact so weird that I am going to go with something is loose in there and is impeding the shift plate - I doubt it is a dog or a shift fork because at this distance I can't understand how either could fail in that way. A failed bearing might cause some of the symptoms, but it would "announce itself" in the usual way.


From memory there are no really "special" tools required - you need a decent puller to get the output flange off, and then bearing separators if you strip down the shafts.

For assembly if you change bearings/bushes you will need a either the specially made dummy end-plate or an old rear cover you can cut big holes into so that you can measure clearances.

Lots of luck and please post pictures of what you find.
Title: Re: Gearbox issue..
Post by: Lucky_Lou on September 26, 2016, 03:42:27 PM
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Next time you are in Honley, shout if I am either at home or in the office (village centre), call in for a brew/chat, kettles always on...
Will do... you haven't changed your mobile have you ?
I will have a play with it at the weekend and post pictures if I find anything.
Lou
Title: Re: Gearbox issue..
Post by: Lucky_Lou on October 02, 2016, 09:50:10 AM
Well bit of a result, adjusted the clutch cable and all seems to be well. I fitted a new cable about 2 years ago, odd that it  was only causing a problem on 3rd gear though.
Lou
Title: Re: Gearbox issue..
Post by: Bob_Roller on October 02, 2016, 11:40:59 AM
Good to hear it was a simple quick fix !!!
Title: Re: Gearbox issue..
Post by: montmil on October 02, 2016, 01:14:51 PM
Well, you got it fixed, Lou. I was going to suggest you replace the Flux Capacitor. Often problematic with AIR-heads.  ;)
Title: Re: Gearbox issue..
Post by: Lucky_Lou on October 02, 2016, 01:33:23 PM
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Well, you got it fixed, Lou. I was going to suggest you replace the Flux Capacitor. Often problematic with AIR-heads.  ;)
I would have changed that too if I could find it.. may have to consult  Doctor Emmett Brown. [smiley=beerchug.gif]
Lou
Title: Re: Gearbox issue..
Post by: Tony Smith on October 03, 2016, 08:43:00 PM
Lou

I am very glad that things worked out for you, your problem was so out of line with my understanding of how the gearbox works that my mind kept coming back and picking at it.

I had decided that the most likely cause was a stray piece of metal lodged in the shift-plate, which then gave rise to the question "where from"? Given that a missing chunk of metal would normally announce its presence or absence in some loud and usually extremely expensive way.


Now I am even more baffled.
Whilst I readily accept that a mal-adjusted clutch will make shifting a bear, my musing is "why only in 3rd"?


Anyway, I am about to start the rebuild of a pre-1981 gearbox (that has a kick starter) as part of my "back to the future" project for my R65, I do not know this box at all other than it apparently shifted perfectly but howled in 3rd and 4th.

I think I'll begin by budgeting to replace all the bearings :-)


Title: Re: Gearbox issue..
Post by: Lucky_Lou on October 05, 2016, 03:24:18 PM
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I think I'll begin by budgeting to replace all the bearings :-)
By the time you get to the bearings you will probably know if owt else is wrong...
I was odd that I was only having issues with 3rd but hey ho... live and learn.
Lou  
Title: Re: Gearbox issue..
Post by: Justin B. on October 08, 2016, 10:23:42 PM
Very strange symptom for a maladjusted clutch.  Glad you got it sorted...