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Knocking in transmission of clutch

mfifer

mfifer

Titan Silver
Guys , I thought I had an issue with the engine but today I started it and listened carfully and it seems to come from the clutch and transmission area.
When the clutch is pulled in it seems to stop. It has a similar sound to a rod knock.
Clutch functions fine and rides well.
I fear the worst.
Any thoughts?

Thanks in advance, Mike
 
mfifer said:
Guys , I thought I had an issue with the engine but today I started it and listened carfully and it seems to come from the clutch and transmission area.
When the clutch is pulled in it seems to stop. It has a similar sound to a rod knock.
Clutch functions fine and rides well.
I fear the worst.
Any thoughts?

Thanks in advance, Mike
Click to expand...

What bike?

The early Oilheads sound a lot like the older Airheads when the gear lube is hot.
It's gear clash. Nothing to worry about. You 'may' need to do a throttle body sync too. That can help a little with the noise.
 
bmwmick said:
What bike?

The early Oilheads sound a lot like the older Airheads when the gear lube is hot.
It's gear clash. Nothing to worry about. You 'may' need to do a throttle body sync too. That can help a little with the noise.
Click to expand...

Sorry , It is a 96 R1100Rt with almost 100,000 miles. It seems to be getting worse in a matter of about 3 weeks and I ride it daily 50 miles. It makes more noise on deceleration and very little on acceleration and sitting still less noise with more RPM.
This one sounds like that from start-up. I am trying to borrow a carb sync.

Thanks , Mike
 
Mike,
Couple of thoughts......
Do you have new lube in the trans? I use 75/140 Mobil 1 and it makes it a little quieter.
You can get an idea if it's bearings or just gear clash by putting it in 4th gear, tie the clutch lever to the handlebar and with the rear wheel off the ground, spin it as you listen to the trans. Bearings will growl. Gear clash will NOT be evident as you spin the wheel by hand.
 
Thanks Mick , I will have to give that a try. We are going away this weekend but will look closer next weekend. I also will try the lube . I bought it with 89,000 on it and do not know the gear lube type.
I am concerned as this noise is new.
Thanks , Mike
 
I think that year/model got the 2nd generation transmission with the rubber O rings as silencers to reduce gear clatter. Not positive but that is my recollection.

If so it is old enough for the O rings to have lost elasticity, allowing the noise to now emerge as new, which is very typical of the early O ring silenced transmissions.
 
PGlaves said:
I think that year/model got the 2nd generation transmission with the rubber O rings as silencers to reduce gear clatter. Not positive but that is my recollection.

If so it is old enough for the O rings to have lost elasticity, allowing the noise to now emerge as new, which is very typical of the early O ring silenced transmissions.
Click to expand...

Given this , would it be wise to continue to use it that way?
It really seems loud, I'll give it a look next weekend.
Does anyone know if the M94 was older and the M97 newer or the exact diffs?
Thanks , Mike
 
mfifer said:
Guys , I thought I had an issue with the engine but today I started it and listened carfully and it seems to come from the clutch and transmission area.
When the clutch is pulled in it seems to stop. It has a similar sound to a rod knock.
Clutch functions fine and rides well.
I fear the worst.
Any thoughts?

Thanks in advance, Mike
Click to expand...

Those were the symptoms I had from a disintegrating bearing in the transmission, and buggered input shaft. You can try to pull the starter and observe the splines, and pull the inspection plug on the bottom of the transmission to see what is clinging to the magnet. I'll hope it is the o-ring issue instead!
 
mfifer said:
Sorry , It is a 96 R1100Rt with almost 100,000 miles. It seems to be getting worse in a matter of about 3 weeks and I ride it daily 50 miles. It makes more noise on deceleration and very little on acceleration and sitting still less noise with more RPM.
This one sounds like that from start-up. I am trying to borrow a carb sync.

Thanks , Mike
Click to expand...

I have the same bike, same year, same mileage, same transmission with the same noise. It is the transmission input shaft gear dogs whacking away as it spins with the clutch engaged, silent when disengaged. The effect (noise) is reduced when oil is cold due to dampening effect of thicker (cold) oil. My transmission was rebuilt a year ago by Anton and i know it is as right as that box of marbles can get.

A smooth running engine (TB sync) and proper idle speed help by reducing (smoothing) the intensity of each power pulse from pistons running through the input shaft. I usually set the idle per spec or a little high, like 1250 RPM. But the noise is still there at hot idle.

Its annoying, but its nothing to worry about. My suggestion in addition to the above, change the T-fluid evry 6K when you change the engine oil so you can inspect the mag plug and fluid for shiny flakes or excessive grey metal powder and enjoy that high miler like i do. -You probably dont owe a penny on it.
 
I can't diagnose a noise looking at a screen and typing on a keyboard. The specific noise in this transmission may or may not be the typical gear clatter in these transmissions.

But - the best description of what causes the gear clash that I have ever found is inserted below. It was written in 1974 by Oak Okleshen, describing the exact same thing encountered when the "new" 5 speed transmissions were introduced on the R90S and /6 BMW bikes.

Quoting Oak -

"The noise is the result of an unloaded transmission and the backlash in the mating parts clattering slightly due to variances in engine speeds when at idle. The engine, though we think of it as running at a constant speed, varies in a miniscule amount when it is unloaded and at low speeds near idle. This happens between the power pulsations from the pistons. The flywheel helps to prevent the uneveness but does not cure the problem entirely for it would take a much larger and heavier flywheel than necessary to make the machine run properly and would detract from acceleration performance. As a result, the engine pulsates and the transmission attempts to run at a constant speed. Between pulsations the backlash in the transmission causes the components to clank lightly and cause noise.

The noise can become more noticeable if ...unbalanced left to right. This causes engine pulsations to become more uneven and, hence, there is more noise in the transmission in neutral, clutch engaged."
 
PGlaves said:
I can't diagnose a noise looking at a screen and typing on a keyboard. The specific noise in this transmission may or may not be the typical gear clatter in these transmissions.

But - the best description of what causes the gear clash that I have ever found is inserted below. It was written in 1974 by Oak Okleshen, describing the exact same thing encountered when the "new" 5 speed transmissions were introduced on the R90S and /6 BMW bikes.

Quoting Oak -

"The noise is the result of an unloaded transmission and the backlash in the mating parts clattering slightly due to variances in engine speeds when at idle. The engine, though we think of it as running at a constant speed, varies in a miniscule amount when it is unloaded and at low speeds near idle. This happens between the power pulsations from the pistons. The flywheel helps to prevent the uneveness but does not cure the problem entirely for it would take a much larger and heavier flywheel than necessary to make the machine run properly and would detract from acceleration performance. As a result, the engine pulsates and the transmission attempts to run at a constant speed. Between pulsations the backlash in the transmission causes the components to clank lightly and cause noise.

The noise can become more noticeable if ...unbalanced left to right. This causes engine pulsations to become more uneven and, hence, there is more noise in the transmission in neutral, clutch engaged."
Click to expand...
Thanks Paul , I understand that principle and the first two items to address is checking the fluid in the trans. and the engine defferantly idles rough (which I am sure translates all the way through the power band).
Gonna try the fluid check and carb sync (plus idle) next weekend.
Thanks , Mike
 
Some folks refer to this as the death rattle. It sound bad, but it a common noise for that year/model. My 1996 R1100RT started making that noise around 70k. I paid my local dealer about $1000 to replace a parts in the transmission to make it quite. About 20k later, the noise returned.

While BMW owners expect absolute quite, Ducati owners love the noise of their rattled clutches. I seen a sticker on the back of one stating Loud Clutches Save Lives. I wouldn't worry about it. Like they say....they all do it.
 
Talked to Anton today and had same recomendations as you all provided.
I know the carbs need to be synced and tonight I changed the oil to a heavier oil and inspected the plug. Also spun the wheel in 4th with clutch tied in and NO GROWL.
Anton is a super nice guy and very sharp. If you ever get a chance and or need him please call him!
Here is what I found. I do not think this is any issue but please advise.
There was no metal in the oil and oil was very clear and has been at least 6000 miles since changed.

DSCN5735-600.jpg


DSCN5736-600.jpg


Thanks , Mike
 
My 2001 R11RT does the same thing. But it only has 23k miles on it. Sounds like a can of rocks with the clutch out but goes quite when you pull in the clutch lever. It's almost due for a professional service at 24k, and the season is getting old...
 
Mike,
Did you pinch that black stuff? You should NOT be able to feel it between your fingers. I think you are safe to continue riding it. :)
 
bmwmick said:
Mike,
Did you pinch that black stuff? You should NOT be able to feel it between your fingers. I think you are safe to continue riding it. :)
Click to expand...

Yes Mick I did and it seems to be very fine. Anton says if the fluid is clear and no metalic suspended in the fluid that all is well and keep driving. I think with the riding I do and piece of mind I now have about the inside of the transmission I will ride it until it starts do skip , jump out of gear , growl , or change in fluid color and particulates , I'll just ride.
She got an oil and filter , trans fluid and diff fluid change this PM.
Still need to balance those pesky TB's. Anton also said most trans noises are GREATLY magnified by un-balanced TB's as you all also stated.
Thanks so much guys!

Mike
 
Similar problem on K75

mfifer said:
Guys , I thought I had an issue with the engine but today I started it and listened carfully and it seems to come from the clutch and transmission area.
When the clutch is pulled in it seems to stop. It has a similar sound to a rod knock.
Clutch functions fine and rides well.
I fear the worst.
Any thoughts?

Thanks in advance, Mike
Click to expand...

This might be totally unrelated to the oilhead, but I'll share my experience with my 92 K75, which, like the oilhead, has a diaphram-spring clutch design. My symptoms were similar: knocking sound in neutral with clutch engaged; quiet when cold but knocking got louder as engine warmed; and, in my case, stiff clutch release. The knock became worse over about ten thousand miles, until it became quite annoying. The service manager at my local dealer figured it might be gear lash knock, and recommended heavier oil, linkage lubrication, and cable replacement as the first things to try.

When those didn't work, I pulled the tranny and looked at the clutch and spring. Both looked good, but the diaphram spring was hard to compress. I replaced both clutch and diaphram. Result: noise completely gone, easy clutch pull, excellent shifting (about 1000 miles now). My theory: the diaphram spring was sticking in places, or just warping slightly as the bike warmed, causing the clutch-disengage pushrod to knock back and forth when the clutch was out (especially noticeable when bike was in neutral).
 
mfifer said:
Here is what I found. I do not think this is any issue but please advise.
There was no metal in the oil and oil was very clear and has been at least 6000 miles since changed.

DSCN5735-600.jpg
Click to expand...

When you last changed the gear lube, did you clean the magnet?

Assuming you cleaned the magnet this time, was any of that "fuzz" slivers or chips, or did it all just feel like grinding dust?
 
rxcrider said:
When you last changed the gear lube, did you clean the magnet?

Assuming you cleaned the magnet this time, was any of that "fuzz" slivers or chips, or did it all just feel like grinding dust?
Click to expand...

Don't hold your breath. His last post in this thread was 7 years ago. :ear
 
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