The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: the_admiral on July 22, 2009, 02:52:19 PM

Title: rattly gearbox?
Post by: the_admiral on July 22, 2009, 02:52:19 PM
HI guys i am slowly getting my 1981 R65 quieter,timing chain replaced,tappets etc.All i have now is a noise from the gearbox that disappears when i pull the clutch in,could this be a thrust bearing issue,its a kind of a rattly sound.Am i worrying too much or is this fairly normal?Also i have a bit of vibration when i reach about 4500 rpm,is this normal also?Thanks in anticipation
Title: rattly gearbox?
Post by: Rob Valdez 79 R65 on July 23, 2009, 08:59:05 PM
[movedhere] R65 Technical FAQ/Procedures [move by] Rob Valdez 79 R65.
Title: Re: rattly gearbox?
Post by: Bob_Roller on July 23, 2009, 09:05:46 PM
That's pretty much normal operation for an old airhead BMW R65 .

So is the feeling that the rear of the bike is raising up when you start from a stop .

Personally, I can't feel the vibration band anymore, let alone he rising feeling from a stop !!!!

The transmission noise is normal as well .
Title: Re: rattly gearbox?
Post by: Mike V on July 24, 2009, 01:23:51 AM
Admiral,
Just a couple of thoughts from personal experience that you can check regarding the rattling. First thing I would do is check the carb balance. Out of balance carbs can cause a push-pull effect and cause some noise to be transmitted in the transmission. Next would be to drain your hypoid and check your magnetic plug for shavings. I recently had noise in my /7 and found out the output shaft bearing was on it's way out (among other things). I hope this isn't your problem. You may want to spin the rear wheel slowly in neutral (with engine off), both hot and cold and listen carefully for noise in the transmission. Bad output bearings will make noise in addition to sending a bit of a rough feel through the shaft and wheel onto your hand.
Hopefully Rob is correct. Yes they do make a bit of noise but a healthy transmission should be relatively quiet. You may want an experienced ear to have a listen sooner than later.
Looking forward to hearing a reply telling me how wrong I am. I wouldn't wish transmission problems on anyone.

Mike V.
Title: Re: rattly gearbox?
Post by: Justin B. on July 24, 2009, 01:30:29 AM
Pretty much normal and varies in intensity between bikes.  When the transmission is in neutral there is no load on any of the gears inside so they just sort of clatter around against each other...
Title: Re: rattly gearbox?
Post by: beemer on July 24, 2009, 04:48:57 AM
Quote
Pretty much normal and varies in intensity between bikes.  When the transmission is in neutral there is no load on any of the gears inside so they just sort of clatter around against each other...
Yep,the "rattle clattle"syndrome! ::)
Title: Re: rattly gearbox?
Post by: weasel01 on July 24, 2009, 08:37:09 AM
+1 on the carb sync...there is a normal amount of extra vibration at 4500 rpm but I had bad vibration as the bike went thru it's rpm range
and after I got the carbs in sync it went WAY down.

I also changed over to heavier dino gear lube and that also seemed to make an improvement.

If you havent done your spline lube you might consider doing it as the throw out bearing service is done at the same time.

Also check you clutch cable adjustment getting that right improved things as well for me.