Hi all - any thoughts regarding a solution to the noise as per the attached video's and sounds?

https://youtu.be/1JgHz3ao-dw


https://youtu.be/1JgHz3ao-dw

hmm a little too short to get to have a good listen but certainly sounds like the rear pinion bearing is dry or oval rollers ?

sounds crazy but why not mount it 90 degrees rotated so the pinion is at the bottom and covered in oil , then let it run for a while ....might free it up somewhat ...pssst the oil will leak from the breather and speedo  take off unless you block those holes ...careful how you go as you will need to support the swing arm  without the shocky mounted up ...some sort of cradle might work ?

was thinking some sort of lighter penetrating oil could help take the varnish and crud off the surfaces of the rollers ...as you wont be loading it up too much ...

or split the drive and you might be able to access the rear of the pinion gear with some carbi cleaner  which might get in there and loosen up the crud ?
resassemble after a good clean out and run it again with new oil sideways til you notice some change ?

the housing does seem to gather crud if left for a long time without work ,...there are loads of nooks and cranies around inside that case ..splitting it might be the only way to clean it out properly


just a thought

Sounds to me like a chipped tooth or maybe packed crud in a pinion tooth judging by the rhythmic frequency  of the noise. Or another possibility is a loose pinion, when I recently stripped my driveline to deal with a clutch problem ( see 'weeping seal' thread) my rear drive which made a similar, though more 'rumbley' noise, was found to have the retaining nut floating loose on it's threads, so after I made up a suitable restraining jig the nut and threads were cleaned, reassembled and torqued up per manual and it is now quiet.

charlie99 wrote:hmm a little too short to get to have a good listen but certainly sounds like the rear pinion bearing is dry or oval rollers ?

sounds crazy but why not mount it 90 degrees rotated so the pinion is at the bottom and covered in oil , then let it run for a while ....might free it up somewhat ...pssst the oil will leak from the breather and speedo  take off unless you block those holes ...careful how you go as you will need to support the swing arm  without the shocky mounted up ...some sort of cradle might work ?

was thinking some sort of lighter penetrating oil could help take the varnish and crud off the surfaces of the rollers ...as you wont be loading it up too much ...

or split the drive and you might be able to access the rear of the pinion gear with some carbi cleaner  which might get in there and loosen up the crud ?
resassemble after a good clean out and run it again with new oil sideways til you notice some change ?

the housing does seem to gather crud if left for a long time without work ,...there are loads of nooks and cranies around inside that case ..splitting it might be the only way to clean it out properly


just a thought

hi charlie please correct me if im " out of order " but ive been watching this thread now and all these "what ifs" , or "maybe its this"  , or "add 10 drops of this and give it a shake " !!  the sound is obviously coming from the final drive  so remove it from the bike and unbolt the side of the housing and actually SEE the cause instead of all the surmising and " what ifs "  then you know what your up against and while your there put a new seal in at the same time and a good clean up see if there are any chipped teeth or crud  here or there  shaking a tin and trying to guess whats inside is a waste of time compared to opening the tins lid and seeing first hand what is making the rattle !! 

woodcutter wrote:

charlie99 wrote:hmm a little too short to get to have a good listen but certainly sounds like the rear pinion bearing is dry or oval rollers ?

sounds crazy but why not mount it 90 degrees rotated so the pinion is at the bottom and covered in oil , then let it run for a while ....might free it up somewhat ...pssst the oil will leak from the breather and speedo  take off unless you block those holes ...careful how you go as you will need to support the swing arm  without the shocky mounted up ...some sort of cradle might work ?

was thinking some sort of lighter penetrating oil could help take the varnish and crud off the surfaces of the rollers ...as you wont be loading it up too much ...

or split the drive and you might be able to access the rear of the pinion gear with some carbi cleaner  which might get in there and loosen up the crud ?
resassemble after a good clean out and run it again with new oil sideways til you notice some change ?

the housing does seem to gather crud if left for a long time without work ,...there are loads of nooks and cranies around inside that case ..splitting it might be the only way to clean it out properly


just a thought

hi charlie please correct me if im " out of order " but ive been watching this thread now and all these "what ifs" , or "maybe its this"  , or "add 10 drops of this and give it a shake " !!  the sound is obviously coming from the final drive  so remove it from the bike and unbolt the side of the housing and actually SEE the cause instead of all the surmising and " what ifs "  then you know what your up against and while your there put a new seal in at the same time and a good clean up see if there are any chipped teeth or crud  here or there  shaking a tin and trying to guess whats inside is a waste of time compared to opening the tins lid and seeing first hand what is making the rattle !! 

hi wood cutter  I wont bother to offer an opinion to you criticism
if you want to have a personal attack at someone's effort to offer an suggestion,  yes you are out of order ... got it ?!!
if you want to add your thoughts then do so without the bullshit . ok ?

charlie99 wrote:

woodcutter wrote:

charlie99 wrote:hmm a little too short to get to have a good listen but certainly sounds like the rear pinion bearing is dry or oval rollers ?

sounds crazy but why not mount it 90 degrees rotated so the pinion is at the bottom and covered in oil , then let it run for a while ....might free it up somewhat ...pssst the oil will leak from the breather and speedo  take off unless you block those holes ...careful how you go as you will need to support the swing arm  without the shocky mounted up ...some sort of cradle might work ?

was thinking some sort of lighter penetrating oil could help take the varnish and crud off the surfaces of the rollers ...as you wont be loading it up too much ...

or split the drive and you might be able to access the rear of the pinion gear with some carbi cleaner  which might get in there and loosen up the crud ?
resassemble after a good clean out and run it again with new oil sideways til you notice some change ?

the housing does seem to gather crud if left for a long time without work ,...there are loads of nooks and cranies around inside that case ..splitting it might be the only way to clean it out properly


just a thought

hi charlie please correct me if im " out of order " but ive been watching this thread now and all these "what ifs" , or "maybe its this"  , or "add 10 drops of this and give it a shake " !!  the sound is obviously coming from the final drive  so remove it from the bike and unbolt the side of the housing and actually SEE the cause instead of all the surmising and " what ifs "  then you know what your up against and while your there put a new seal in at the same time and a good clean up see if there are any chipped teeth or crud  here or there  shaking a tin and trying to guess whats inside is a waste of time compared to opening the tins lid and seeing first hand what is making the rattle !! 

hi wood cutter  I wont bother to offer an opinion to you criticism
if you want to have a personal attack at someone's effort to offer an suggestion,  yes you are out of order ... got it ?!!

hi charlie it was not meant to be a personal attack on you or anybody else but wouldn't it be a lot easier to say ok the noise is coming from the final drive lets open it up and see what is causing the sound  everything else seems to be delaying the inevitable  so don't take it personally mate ok ive always been that way if somebody knocks at the door i open it where as other people look out the window and ask " who's there" have a great w/e i am, off on the beemer for a ride tomorrow  pub lunch , with my mate on his bike  cheers

Hey guys come on over here for a beer and a banter.

The forum is great for us all and we Eccentrics enjoy everyone's company. Everyone is trying to help and sometimes one comment does bring out another idea.

We call it a beer.

:LP:Guess we could send over a few leprechauns to deliver the beer butt hose little green critters usually make things disappear.

all good olaf

we all need to express our opinions  but in the end we are all friends with a common goal at helping each other when we can ...appreciate the support  for all in here

thanks from down here mate

I know its all good!!

Us Eccentrics are passionate about things too. Without passion there would be no Ks and no forum.

Hi All, thanks heaps for your collective input. When the bike runs with the FD removed, there still is a rumbling noise but not as severe. I will split the both FDs today and see what happens. Trouble is , the condition of the FDs are unknown. All will be revealed. Cheers Tom

G'day All, a  quick update. Split both FDs (from the recent K75 and donor bike) and found no chipped teeth in the crown wheels or pinion drives. Both FDs were pretty clean.
Fitted the FD from the 'good' 75 to the new 75 and same rumble. Fitted the suspect FD from the new 75 to the old 75 and same rumble. This may mean a crook FD and a crook gearbox output shaft bearing.  Will keep you posted. Cheers Tom

Tom, in other words you may have a few crooks..maybe a gang?

that's not so good news tom ..
as I messaged you, the crook output shaft could transfer a lot of its noise to the fd
I would still be doing a clean up of both the pinion bearings  before reassembly with some carbi cleaner ?
did you perhaps turn the large output bearing in the fd  whilst apart and listen- feel for some roughness ?

good luck mate

Tom, I'd pull the drive and see if the front Uni is rough before thinking the Gearbox rear bearing is an issue. The old FD may be noisy on the new 75 because the noise is forward of it. The new FD on the old75 may just be noisy, but as Charlie says clean em up and maybe they'll settle down with new oil. Sure would be beneficial to drown the bearings in brake fluid cleaner or carby cleaner to ensure they are degrunged, if that a word.

I have sympathy with you Tom and your noisy final drive. 
My original final drive had  worn out put shaft splines, so I got a spare from Motoworks uk with, as new splines, and had my drive  shaft splines renewed at the same time. 

Since fitting the new final drive from Motorworks, and I am not attaching blame on them , I have suffered a weird " rubbing" sound from the back of the bike. 

The frequency and noise is as if one part of the tyre is rubbing on the swing arm.
The sound from mine is very different to yours, more rubbing than metallic.
I have no play on the swing arm, and a good enough gap between both, so with the noise only there after the second final drive was fitted, then it is from there .

I can hear the noise at low speeds, wearing ear plugs, up to 30 mph or so and after that it lost amongst the general engine and road noise. 

The final drive does feel slightly rough and noisy when rotating the back wheel, but that might be my lack of experience with listening to final drive / driveshaft noises.
 There is no play on the bearings when pulling / pushing the wheel.

I can hear the noise even when using either front or back brakes....

 Someone has  attempted to remove the castellated nut on the output shaft , only to peen over all four lugs... nice . I will use the good one from my original unit.

The output shaft seal weeps very slightly  I have only topped up the final drive once, and then only a very small amount.


I will try and capture the sound with the bike, VERY CAREFULLY set  on the centre stand, and post it if it audible.

I will strip the drive anyway over the xmas period, as I want to swap the output shafts, and fit  new bearings and seals all round. 

It is typical that the quiet box has the worn splines, and the noisy box has near perfect splines.. sods law I guess. It will be mix and match time over  Xmas

 Expect a help thread from me at some point.
Bob

Thank you all for your input. Will do those bits as suggested and will also try the drive shaft out of the 'known' good 75. Will keep you posted. Thanks again Tom

G'day All, just a quick update on this issue. Received G/box input shaft from Rick and now in process of replacing all bearings in original g/box. Fitted spare K100 transmission to my 75 and ran it without D/S or FD - no rumbling noises. Fitted original DS and FD with original rumbling noise persisting. Then fitted loaner FD from Rick G and behold, no more rumbling noises meaning that original FD is kaput.
With a bit of luck the old blue 75 will be back on the road by Monday afternoon.
Thank you all for your help in this issue.
Tom

good to hear that you have narrowed it down tom

good luck

G'day All, just a quick update on this issue. Got the blue 75 back together after fitting the K100 gearbox and FD received from Rick. All good - drives well and gear changes are good without any unwanted noises. Before doing this, Rick's FD was run in the 'purple' 75 and all went well without any unwanted noises. In the end, both 75's had the same problems. A crook clutch plate, a crook GB input shaft, a crook UJ and a crook FD. Thank you all for your collective inputs and suggestions. Cheers Tom

Good to see Tom. Glad to see another 75S heading back on the road.

Tom Grabau wrote:In the end, both 75's had the same problems. A crook clutch plate, a crook GB input shaft, a crook UJ and a crook FD. Thank you all for your collective inputs and suggestions. Cheers Tom

That sounds like real bad luck to me Tom. And expensive too.

Good to hear you're back on the road Tom.

Hi Dai, bad luck alright and expensive. It was also a bit of a learning experience but all is good now. Holister, it is good to be on the road again. My next problem is to tackle the drive shaft in the R100R. Now, that will be a new experience. Cheers Tom

Tom Grabau wrote:Hi Dai, bad luck alright and expensive. It was also a bit of a learning experience but all is good now. Holister, it is good to be on the road again. My next problem is to tackle the drive shaft in the R100R. Now, that will be a new experience. Cheers Tom

Nice work Tom, great to hear that you got to the root of the problem eventually. Now the Kittens are purring again - you can simply ditch the R!!

That's very harsh of you BAE to speak of our boxers like that. 

While the Ks are the backbone of the touring fleet Tom & I enjoy a run on the boxers when we get them out.

Cheers

Gaz wrote:That's very harsh of you BAE to speak of our boxers like that.