Hey Everyone if you coukd help I’d be really thankful.

Awhile back i shared a post about my gears being very hard to shift down in. Duck was one of the people who helped diagnos that the issue was likely dry splines. It turned out Duck and I live fairly close so i went over to his place and we took the backend off and lubed all the splines which it clearly needed. After putting some miles on the bike the gears started to shift as they should. Problem solved.

About a month ago my clutch cable broke. I finally replaced it last week and was back on the road. Ive taken the bike out for some medium length rides and noticed my gear lever was hard to shift down in again. Problem back

Yesterday i went to take the K for a ride and as i accelerated into 2nd gear and rolled on the exceleratot the bike suddenly lost acceleration and started making this horrible screatching noise as I tried to give it more throttle. I pulled over dropped the bike into 1st gear, let out the clutch and the gear didnt engage. The foot lever feels as if it is going into all the gears, but when i let the clutch out the bike just idles as if its in Neutral. As the bike idels you can hear a little screatching noise, but if you roll on the throttle the noise becomes signifcantly worse the more throttle you give it.

Sympton Summary
- The clutch cable is good and installed to spec
- The foot lever shifting the gears clicks into all the gears smoothly as it should
- When i put the bike in gear and release the clutch the bike continues to idel as if its sitting in Neutral rather than engaging.
- The screatching noise can be heard slightly as the bike ideals
- The screatvhing noise becomes even more loud as i roll on the throttle (the more throttle i give it the louder and worse the screatvhing noise bevomes.

Does anyone have any idea what has happened.

What condition is the final drive splines. If you have no drive in any gears I'd be looking there.
Regards Martin.

They looked good when Duck and I lubed them

tjh1985 wrote:i went over to his place and we took the backend off and lubed all the splines which it clearly needed.

Does this mean you lubed the transmission input splines that engage the clutch disc hub, too?

Yes - I think we lubed 3 different splines

Would those issues creating the loud scratching?

Yes. The combination of noise and no forward motion indicates that as one possibility. The clutch hub splines might have broken and the noise is caused by the transmission input spline ratcheting over them. If they were severely worn that would have been noticed but that's the most likely source of the symptoms.

Do you recall seeing the clutch assembly during this procedure?

For the amount of time required to check the final drive splines I'd pull off the final drive. If you are loosing drive in all five gears you need to go to a common point, one of which is the final drive and shaft.
Regards Martin.

Could it be caused by the scrub screw?

tjh1985 wrote:Could it be caused by the scrub screw?

I haven't read of a noise associated with that grub screw. Did it sound like the video?

No but it seemed to come up with the shift lever being difficult to shift down

Haven’t seen a video referring to the noise

Here.

Any idea what the cost might be to have a professional fix it?

Did it sound like the video?

That video for sure replicates my Problem

You can fix it yourself if it is caused by worn clutch disc hub splines; just replace the clutch disc. If the noise is caused by worn splines on the input shaft, that is a complicated procedure that has been done by amateurs that had tools, time, knowledgeable advice, and patience sufficient for the task. The only way you'll know is to remove the transmission and take a look at the two parts. If the transmission input shaft is worn, a used transmission with a good shaft might be the least costly way to go.

To clarify, you didn't remove the transmission when the splines were being lubed; only the final drive and driveshaft were removed? Was the swingarm removed. We haven't ruled out those components as noisemakers yet but I'm not clear about what was serviced.

I know the swing arm came off for sure

Not sure if those pics help

It's really hard to tell from the pictures but I think it could be the clutch plate splines. But as the final drive has to come off anyway start taking it apart, cleaning and inspecting as you go. If the final drive and. shaft proves OK pull the gearbox and clean and check.
Regards Martin.

tjh1985 wrote:Not sure if those pics help

They have clarified that the transmission was removed also and its input shaft splines were lubed. Thanks for posting them.

I have a 1985 RS do I have to find a transmission from the exact same bike?

tjh1985 wrote:I have a 1985 RS do I have to find a transmission from the exact same bike?

The first step is to confirm whether the noise comes from damaged shaft splines, clutch disc hub splines, or something else. That will involve inspection. If a replacement transmission is considered as part of the solution, it does not need to be from exactly the same model.

Posting a YouTube video of the noise your bike is making might be helpful.

Great advice - I’ll pull it out tomorrow and do just that.

I'd clean up the input shaft on the gearbox and have a good look, It looks stuffed to me, Also check the clutch as when I expand the pics the splines seem to be non existent.

I really, really don't think it's the clutch splines. They were in good shape when I lubed them 100 miles ago.  I've spoken to TJH on the phone about this and it sounds like something internal to the transmission to me.

And when I stripped the clutch splines on one of my early Ks they did not make any horrendous screeching or grinding noise.Once they strip the clutch disk just spins on the trans input shaft and doesn't make much noise at all.

And the drive shaft splines showed hardly any wear.

tjh1985 wrote:I have a 1985 RS do I have to find a transmission from the exact same bike?

No, any K100 or K1100 transmission will work.  (Or even a K75 but 5th gear is 3% "shorter" on those.)

I would suggest disassembling the drive train starting from the final drive.  Inspect each part as it's removed, posting photos here.  Since you haven't mentioned where the screeching is coming from it is difficult to say where you should concentrate your efforts.

Before taking things apart answer this question.  Can you easily spin the rear wheel by hand with the transmission in gear?

When you start taking the drive train apart.  After the final drive and the drive shaft are removed, start the engine and try running through the gears listening for the noise and watching to see if the transmission output shaft is turning.  Tell us what you see before going further.

Its this Pic that throws me

While it is difficult to isolate EXACTLY where the screaming is coming from it seems to be centered where the clutch arm attaches.

Also the noise increases depending on how much throttle I give it. As it idols there is very faint screeching and as I give it throttle it is ver loud.

Perhaps the Clutch Actuator rod is stuck or seized in the engine thus partially holding the clutch in and hence no gears. Does the clutch go all the way out? If the rod spun it would scream its head off?? One would think.

Hang on I change that scram to scream

Press the blade of a screwdriver onto the intermediate housing attached to the engine as indicated in the image, touch your ear to its handle and rev the engine. Does that locate the noise?

Hi tjh1985,

disconnected from your previous problem of gear shift lever, I had a similar problem of transmission with my K100 85'.
Arriving at a corner, I shited down from 3 to 2 and lost my power. The motor was reacting correctly to my throttle, but not the rear wheel.

I first suspected my clutch and unmonted the rear arm and the gearnox from the bike. Every thing was OK.

Nevertheless, I tried to turn the clutch plate and realized it turns when pistons were staying in place.
So, the problem was inside the engine block.

I totally unmonted the cluch and after unmunting the clutch carter and the water/oil pump, i have found the Absorber gear wheel damaged on the engine output shat.




That the sickness of Kseries in their fisrt years with agsorber gear wheel assembled with only 6 rivets.


You can replace it with a used 12 rivets model from K75, K100 or K1100 bikes. K1200 models are "upgradable" to fit with your cluth housing (I did that).

Hope it could help you, even if that could be some bad news.

me/my wife have experienced loss of drive from both stripped clutch/input shaft splines and stripped pinion spline, driveshaft splines in the final drive.

Al

Laitich - can you give me an idea of what it cost to make make your repair?

AL-58 - appreciate your input. It’s a mystery so any tips will help me solve it.

Tranny repair is beaucoup bucks cheaper to find a good replacement on the interwebs

Tranny threads to familiarize should you repair yourself

https://www.k100-forum.com/t2785-very-lound-rattling-sound-when-reving-at-cold-engine

https://www.k100-forum.com/t15394-stuck-in-4th-gear-for-a-few-hours-then-hard-to-shift#180431

Grub screw related

Reply #4 http://www.motobrick.com/index.php?topic=2579.0

http://www.motobrick.com/index.php?topic=9353.0

Part 1 https://www.youtube.com/watch?v=SI6YHhboHJw

Part 2 Inside of the tranny/gearbox and the actual Grub screw shown https://www.youtube.com/watch?v=zVea8TByyT8

Part 3 https://www.youtube.com/watch?v=GOR3Ckfkbsc

tjh1985 wrote:. . . can you give me an idea of what it cost to make make your repair?

Have you located the noise? If it's just replacing the clutch disc, probably less than $200 in new parts sourced online. That's the cost without tangling with obsessive concern for the future;   however, the cost cannot be calculated until the problem is identified—including other faults that might be found along the way.

That 85 is a one hit wonder. Here's some added info for your fall/winter reading until you sort things out.

Notable differences of the pre-85/86 K100 are the seat pan design with matching tail cowl section, the water/oil pump design changed, throttle cable design and fuel tank/fuel level sender/fuel return check valve.

Your '85 may have the European "hotter" cams known as "Finest Year K"

http://www.motobrick.com/index.php/topic,3653.msg56782.html#msg56782

https://forums.bmwmoa.org/showthread.php?4534-Why-is-the-85-K100-the-quot-Finest-Year-K-quot&s=66f149b3cadea44550d51fbf0b9ee793&p=42512&viewfull=1#post42512

The pre-1985/86 has molded pillion handles as part of the seat pan, metal or plastic seat pan.
Post-1985/86 removed handles from seat pan and added handles to the tail cowl section.

http://www.bmwkbike.dx.am/CLseats/kbikeseats.htm

Water Pump
pre-1986-87? original design old style impeller 11411461177

Superseded by 11412325850 design change the shaft with gear Z=32 teeth, shaft- 11411461183

Superseded by 11417676366 same shaft with gear Z=32 teeth

latest design 11517676371 design change shaft with gear Z=19 teeth, shaft- 11411461793

Throttle cables have 2 versions and lower brackets. Cable lengths vary with handlebars.
#1 version- have a adjustment sleeve approx. halfway down length
2nd version black plastic collar at the lower end or a white plastic collar

Pre-1985 fuel tank has a rear mounting tab later removed.
Early fuel lever sender is a thermistor type later is a float type.
[url=http://www.kforum-tech.com/how-to/Modification for early gas tank.htm]http://www.kforum-tech.com/how-to/Modification%20for%20early%20gas%20tank.htm[/url]

Check condition of the inside of fuel tank. Lowest portions are prone to corrosion when moto is left sitting for some time.
Not many 85 tanks left around in this condition
ebay 85 Tank