The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: chris_blake on August 22, 2008, 01:00:11 PM

Title: gearbox noise
Post by: chris_blake on August 22, 2008, 01:00:11 PM
hy guys i have a problem with i think my gearbox . it started with a vibration from thebike at first i thought it was a rear tyre or wheel but now i am getting a whinning noise. the noise usualy starts above 30 40 mph  but is very loud when you shut off the throttle slowing down from 50mph or above. i checked the gearbox oil level and found particles of metal on both drain and filler plugs so i changed the oil but the noise and vibration persist could it be the drive shaft splines i hope not i understand this is fairly major to put right the bike is 86 r65 with 25 thousand miles any help welcome cheers chris
Title: Re: gearbox noise
Post by: mikethebike on August 22, 2008, 01:42:24 PM
If you have metal on the drain and level plugs it seems that you have either gearbox bearing failure or deterioration of the gear mating surfaces. :'(
Title: Re: gearbox noise
Post by: montmil on August 22, 2008, 05:15:31 PM
Quote
If you have metal on the drain and level plugs it seems that you have either gearbox bearing failure or deterioration of the gear mating surfaces. :'(

Yeah, what Mike says. It will not heal itself. You may want to begin some research as to what a kidney is selling for on the black market.  :'(
Title: Re: gearbox noise
Post by: willr65 on August 22, 2008, 05:48:09 PM
It does sound like a bearing is failing. As the others say - check the magnetic drainplug for metallic "grit".
It is expensive to buy a reconditioned gearbox but if you can do it yourself it's a hell of a lot cheaper. I found the hardest thing was re-shimming the shafts. I bought a shimming plate (after doing my box twice) which I'll probably never use!

Get it sorted before it fails!
Title: Re: gearbox noise
Post by: Rob Valdez 79 R65 on August 22, 2008, 05:55:18 PM
Quote

Get it sorted before it fails!


[size=16]+1[/size]
Title: Re: gearbox noise
Post by: willr65 on August 22, 2008, 06:23:52 PM
Just checked my archive and it's probably the only thing I've not taken a picture of!   >:(
Title: Re: gearbox noise
Post by: chris_blake on August 22, 2008, 11:52:02 PM
thanks everybody something i have just noticed even with the bike in neutral at a standstill when i turn the rear wheel by hand it is not right i still cant tell if the noise is from the gearbox or driveshaft but if i move the back wheel a very small amount there is a clicking noise i think is coming from the drive shaft  any ideas cheers chris
Title: Re: gearbox noise
Post by: Justin B. on August 24, 2008, 08:09:52 PM
My '95 R100RT had the same symptoms, increasing whine in all gears and I could hear a clunk coming from the driveshaft area when I pushed it into the garage.  Upon pulling the transmission (after checking U-joint) the cause of the clunking was quite evident, I could barely turn the output shaft with my fingers.  It would rotate for about half a turn, get real tight, etc.  I sent mine to a local indie shop and had it overhauled...
Title: Re: gearbox noise
Post by: nhmaf on August 25, 2008, 11:37:47 AM
I think that having a "spare" airhead transmission around is one of the best investments one can make - It sounds like it is going to need work - and if you send it out for refurb it will typically cost around $600 or so.    If you shop around and are patient, you may "score" a rebuilt transmission for about the same amount of $$, and be able to get your original transmission rebuilt at your leisure, and thus have a future "spare" unit.   On the plus side, these transmissions are the same for the R65, R80, R100, so you can
use it as a spare part for any other similar vintage airheads you may own, or you can usually easily sell them to other airhead owners in desperate need.

If getting a transmission rebuilt, it is advisable to have the "circlip fix" done to it, if it is a late 80s - early 90s transmission - I cannot recall the first year that BMW omitted
putting the circlips in, but perhaps it was 86.   To install the circlip will cost more labor $$$, but would be worth it to have a bulletproof tranny in the future.
Title: Re: gearbox noise
Post by: Mr_Smart on August 25, 2008, 04:39:28 PM
God member indeed !!.....nhmaf..am I reading you correctly ?

R65,R80,R100 Transmissions are interchangeable ?

My 1979 R65 is exhibiting the EXACT same symptoms as Chris Blake`s and I have a friend with a SPARE 1980 R100 Tranny lying on his garage floor...... Is this a cause for rejoicing ??
Title: Re: gearbox noise
Post by: nhmaf on August 25, 2008, 06:41:58 PM
Hmm,  well you *might* be in luck !  I do know that they are interchangeable from '81 - on, but the 79 &'80 models
of the R65 were a little bit different.  Still, I think it merits close scrutiny as I *think* it will work, I just don't know as
much about the '79 and 80 model year bikes.
Title: Re: gearbox noise
Post by: Justin B. on August 25, 2008, 10:11:05 PM
As far as I know the transmission will fit between all models as long as they are for the same "flywheel" type.  In other words, the '79 and '80 used the heavy flywheel and the '81 and later use the lightened flywheel.  I believe the difference is in the input shaft of the transmission and it is possible to migrate a transmission across series by changing to the correct shaft, but that sounds like a lot of work.

The tranny in my '95 went at about 50k and I had been watching e-Bay for about a year to snag a spare tranny, which I did.  I was able to get a recently (according to seller) rebuilt from a 1982 R100RT for $300 plus shipping.  It has been in my '95 for three seasons now and I had my original rebuilt locally for my "spare".  
Title: Re: gearbox noise
Post by: Semper Gumby on August 26, 2008, 05:55:37 PM
+1 what Justin Said.  There is a difference in the clutch actuating rod length between the heavy fly wheel 1979-1980 model bikes and the light flywheel bikes.  This is the rod that comes out the front of the input spline.  If you switch one for the other the rod may be too long or too short.  In either case you will probably not be able to adjust it out at the handlebar or the rear of the tranny.  Becareful...do not mix apples and oranges.