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1Back to top Go down   K75 gear box/clutch clanging noise. Empty K75 gear box/clutch clanging noise. Tue Oct 11, 2022 8:50 pm

Kim Hunter

Kim Hunter
active member
active member
Hello Members.

I have recently noticed a loud clanging noise coming from the gearbox/ clutch area.
This is happening when in neutral. If clutch lever is pulled in, the noise disappears, returns again when lever released.
My bike is 1989 model with about 65,000 km travelled. All original condition, not been messed with.

Any assistance greatly appreciated.

    

Rick G

Rick G
admin
admin
I would say that you have little choice but remove the gearbox and check it out. I can think of quite a few things and all need the gearbox removed and the clutch inspected.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

TacKler

TacKler
Life time member
Life time member
I suggest you obtain a manual if you don't have one already.  The removal is straight forward but a manual will explain the clutch rod difference in setup between the 75 and 100.  

The gearbox weighs about 20kg and on the 75 there is a finicky bit on installation that is made easier with a third hand.  A small trolley jack will save you some grief.


__________________________________________________
Red 1991 K75S
    

Kim Hunter

Kim Hunter
active member
active member
My bike work bench currently has a tennant. as soon as it is free I will get K75 on it.

    

moriarti

moriarti
Life time member
Life time member
Clymer manual is the best. Personally i drain the gearbox oil before removal saves a lot of mess. Very Happy On refill i use 300ml of moly slip or similar product with the oil, gives a smoother gear change


__________________________________________________
1984 k100 rs red/black VIN  0004449 Now sold to Olaf
    

duck

duck
Life time member
Life time member
TacKler wrote:I suggest you obtain a manual if you don't have one already.  The removal is straight forward but a manual will explain the clutch rod difference in setup between the 75 and 100.  

The gearbox weighs about 20kg and on the 75 there is a finicky bit on installation that is made easier with a third hand.  A small trolley jack will save you some grief.

A K755 transmission "only" weighs about 33#. (15kg) I know from shipping them.

https://shop.maxbmw.com/fiche/PartsSearch.aspx?&searchtype=undefined&parts=23001454827

If you sit on the ground behind the bike then you can remove/replace the transmission without the need for any jack or whatever to support it. I've done it a million times. If the bike is on a lift then you probably would want something to support it.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

duck

duck
Life time member
Life time member
moriarti wrote: On refill i use 300ml of moly slip or similar product with the oil, gives a smoother gear change

What he said. I use about a half a tube (25g) of this moly additive - LIQUIMOLY #2019:

K75 gear box/clutch clanging noise. 51ht8k4qt8L._AC_SY879_


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

92KK 84WW Olaf

avatar
Life time member
Life time member
If you replace two of the gearbox bolts with lengths of threaded rod or long bolts you can slide the gearbox back until it slides past the pushrod. If you box clever the entire rear end comes off as one, you leave the wheel on and slowly roll it back as a complete assembly. Using bolts means they act as a stop once you are clear of the pushrod [this works for clutch spline lube too]. If you use threaded rod with a nut on it as a stop, just spin the nuts off and slide it all clear. Very easy single handed.

Refitting, as they say, is reverse procedure.  

Drain the gearbox and final drive first. Just makes it less messy when the wheel and gearbox fall over on to their side..

The complete assmbly is a lot more than the 15kg of the gear box but being on the wheel you dont actually end up lifting it.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Laitch

Laitch
Life time member
Life time member
Kim Hunter wrote:I have recently noticed a loud clanging noise coming from the gearbox/ clutch area.
Posting a video containing that sound on YouTube then publishing its link here would help some of us determine the character of the clang (tapping of the outboard arm of the clutch lever on the muffler, or a foreshadowing of Armageddon) and its pitch. Smile


__________________________________________________
1995 K75 90,000 miles
    

duck

duck
Life time member
Life time member
92KK 84WW Olaf wrote:The complete assmbly is a lot more than the 15kg of the gear box but being on the wheel you dont actually end up lifting it.

I take everything apart when I do a spline lube so it does only weigh 15kg. (Plus the clutch arm's weight. Very Happy)

K75 gear box/clutch clanging noise. OQFFqJy


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

RS Rider

RS Rider
Gold member
Gold member
moriarti wrote:Clymer manual is the best. Personally i drain the gearbox oil before removal saves a lot of mess. Very Happy On refill i use 300ml of moly slip or similar product with the oil, gives a smoother gear change

Interesting. About 1/3 of your gear box content is an additive/supplement as it's only about 950ml. I use 10% or about 100ml. I wouldn't pretend to know how much is allowable though. I use Moly Slip Gear Oil Supplement.

    

moriarti

moriarti
Life time member
Life time member
Me nether, a lot of my knowledge/information is from old school engine builders/tuners. The gearbox is more Tractor than sports bike but Moly does make a hell of a difference. Use a little or more as you think best. 

Dismantling.... Personally i would remove item by item, this allows inspection of parts as you go rather than removing as a lump. Very Happy


__________________________________________________
1984 k100 rs red/black VIN  0004449 Now sold to Olaf
    

RS Rider

RS Rider
Gold member
Gold member
moriarti wrote:Me nether, a lot of my knowledge/information is from old school engine builders/tuners. The gearbox is more Tractor than sports bike but Moly does make a hell of a difference. Use a little or more as you think best. 

You'd think there would be a limit as to how much additive/supplement can be used to enhance gear box smoothness because the actual lubricant itself is being supplanted. Short of doing perhaps destructive testing (which would take time) how would one know where to stop as regards quantity added? Just thinking out loud.

    

duck

duck
Life time member
Life time member
RS Rider wrote:
moriarti wrote:Me nether, a lot of my knowledge/information is from old school engine builders/tuners. The gearbox is more Tractor than sports bike but Moly does make a hell of a difference. Use a little or more as you think best. 

You'd think there would be a limit as to how much additive/supplement can be used to enhance gear box smoothness because the actual lubricant itself is being supplanted. Short of doing perhaps destructive testing (which would take time) how would one know where to stop as regards quantity added? Just thinking out loud.

Molyslip recommends a minimum of 5% which would be 40 ml. (But no maximum.)

Liquid additives are just gear oil with the moly in suspension so it's probably not the end of the world if you put in "too much."


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

RS Rider

RS Rider
Gold member
Gold member
duck wrote:
RS Rider wrote:
moriarti wrote:Me nether, a lot of my knowledge/information is from old school engine builders/tuners. The gearbox is more Tractor than sports bike but Moly does make a hell of a difference. Use a little or more as you think best. 

You'd think there would be a limit as to how much additive/supplement can be used to enhance gear box smoothness because the actual lubricant itself is being supplanted. Short of doing perhaps destructive testing (which would take time) how would one know where to stop as regards quantity added? Just thinking out loud.

Molyslip recommends a minimum of 5% which would be 40 ml. (But no maximum.)

Liquid additives are just gear oil with the moly in suspension so it's probably not the end of the world if you put in "too much."

Good to know. Perhaps I will bump up the quantity I use to 200-250ml.


    

moriarti

moriarti
Life time member
Life time member
Ivhad myK for 25yrs and over 44000 miles no problems with gearbox at all, Water pump is the only mechanical fail in all this time. Maybe im just lucky K75 gear box/clutch clanging noise. 652573 K75 gear box/clutch clanging noise. 652573

Iv used moly from first service/oilchange


__________________________________________________
1984 k100 rs red/black VIN  0004449 Now sold to Olaf
    

92KK 84WW Olaf

avatar
Life time member
Life time member
Kim Hunter wrote:Hello Members.

I have recently noticed a loud clanging noise coming from the gearbox/ clutch area.
This is happening when in neutral. If clutch lever is pulled in, the noise disappears, returns again when lever released.
My bike is 1989 model with about 65,000 km travelled. All original condition, not been messed with.

Any assistance greatly appreciated.
In the dark remnants of memory on a K1100 a clanging sound . . . . . . . loose exhaust header and the retaining ring rattling.

I'd do a bit of checking in there around the clutch lever, exhaust and headers for anything at all that's loose, heat shield, side stand bump stop etc.

Pulling the clutch lever changes the vibration pattern.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Kim Hunter

Kim Hunter
active member
active member
I did some more investigation this afternoon.
Found nothing loose.

I then warmed engine and gearbox. Then I used a metal rod and placed one end at various points on the gearbox and put my ear on the other end.
The sound is very metallic banging and is coming from the rear of the gearbox. 

I am thinking possibly output shaft end play.
Gearbox oil is clean, no metallic glitter.

    

92KK 84WW Olaf

avatar
Life time member
Life time member
The weird part is the fact that it disappears when you pull the clutch. 

That suggests its either a vibration noise that changes when you pull the clutch due to the engine vibration frequency change or if its mechanical something either at the engine output shaft, the clutch itself or on the input side of the gear box as its only happening in neutral with the clutch engaged/disengaged.

When you are in neutral there is no drive at all through the gearbox to the gearbox output shaft so even though you are hearing it there, it can't be at that point.

It could be inside the bell housing but as said a split is required.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Laitch

Laitch
Life time member
Life time member
Rick G wrote:I would say that you have little choice but remove the gearbox and check it out. I can think of quite a few things and all need the gearbox removed and the clutch inspected.
Olaf wrote:It could be inside the bell housing but as said a split is required.
I'm detecting a trend here. Smile


__________________________________________________
1995 K75 90,000 miles
    

92KK 84WW Olaf

avatar
Life time member
Life time member
Can you post a video of it? Clanging says to me almost like sheet metal and absence of the rubber bump stop for the stands could do this. I have spent so much time in my life dealing with rattles and the worst one was one a car I had. Turned out to be heat shield on the transmission and nothing worse, main dealer wanted to pull the transmission out of it.

Your mileage is quite low and wear is not normally an issue on a K bike.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

22Back to top Go down   K75 gear box/clutch clanging noise. Empty Re: K75 gear box/clutch clanging noise. Fri Oct 14, 2022 10:10 am

Point-Seven-five

Point-Seven-five
Life time member
Life time member
When the clutch cable on my K75RT was adjusted for 75mm the lever clanged on the muffler.  Pulling the clutch in made the noise stop.  Adjusting the free cable length a tiny bit shorter to 72mm stopped the clanging.  You say it sounds like it's coming from the rear of the transmission and that's where the lever is.

A quick check would be to put a rag between the lever and the muffle and see if the clanging stops.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

23Back to top Go down   K75 gear box/clutch clanging noise. Empty Re: K75 gear box/clutch clanging noise. Fri Oct 14, 2022 10:50 am

Laitch

Laitch
Life time member
Life time member
Here's a selection of Brick engine noises, Kim. Any of them sound familiar? Keep scrolling; they're interspersed with other videos.


__________________________________________________
1995 K75 90,000 miles
    

92KK 84WW Olaf

avatar
Life time member
Life time member
Point-Seven-five wrote:When the clutch cable on my K75RT was adjusted for 75mm the lever clanged on the muffler.  Pulling the clutch in made the noise stop.  Adjusting the free cable length a tiny bit shorter to 72mm stopped the clanging.  You say it sounds like it's coming from the rear of the transmission and that's where the lever is.

A quick check would be to put a rag between the lever and the muffle and see if the clanging stops.
The pivot arm if not clipped in position with the C clips can slide toward the muffler too. For what its worth I think the cause of the noise is in this area or in some way connected with the exhaust.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

25Back to top Go down   K75 gear box/clutch clanging noise. Empty Re: K75 gear box/clutch clanging noise. Fri Oct 28, 2022 12:03 pm

gabriel

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Platinum member
Platinum member
I’m thinking perhaps the clutch friction plate splines are stripped which might explain why you don’t hear the noise when you disengage the clutch.
Check your gearbox input shaft splines…. Good luck


__________________________________________________
;BMW; 1984 BMW k100..frame number 6228?
1992 BMW K75s
    

26Back to top Go down   K75 gear box/clutch clanging noise. Empty Re: K75 gear box/clutch clanging noise. Fri Oct 28, 2022 10:11 pm

92KK 84WW Olaf

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Life time member
Life time member
gabriel wrote:I’m thinking perhaps the clutch friction plate splines are stripped which might explain why you don’t hear the noise when you  disengage the clutch.
Check your gearbox input shaft splines…. Good luck
The bike only has about 42,000 miles on it. I am struggling to think this could happen in that mileage. Unless of course the mileage is not genuine. 

Has anyone been in at the clutch before?

It would be good to confirm and eliminate things like heat shield, manifold/silencer joint, monkey nuts, clutch pivot pin/exhaust contact, side stand/muffler contact.



Last edited by 92KK 84WW Olaf on Sat Oct 29, 2022 9:18 pm; edited 1 time in total


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

K75cster

K75cster
Life time member
Life time member
I'd make absolutely sure that the clutch arm isn't hitting the muffler before pulling everything apart.


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

28Back to top Go down   K75 gear box/clutch clanging noise. Empty Re: K75 gear box/clutch clanging noise. Sat Oct 29, 2022 12:27 pm

Laitch

Laitch
Life time member
Life time member
Word on the vine is the OP is treating the condition by smudge ritual, periodically kindling small fires of sage beneath the gearbox/engine joint and allowing the restorative smoke to wend its way into the works. Update to come, hopefully.


__________________________________________________
1995 K75 90,000 miles
    

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