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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: VelvetElvis666 on September 14, 2015, 02:15:55 PM
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Ok... I am about to rip my hair out and need help.
Recently my 17,000 mile '93 k75s had the input shaft on the gear box replaced among other things. Previous repairs for notchy shifting were attempted to be fixed by TransAm BMW in Lititz, PA. Both repairs replaced some of the same parts at 6k and 9.4k. Shift drum, etc. This time, the input shaft was worn and the expected culprit was misalignment of the transmission to the engine....
On counsel from Bob's BMW I purchased a second hand intermediate housing which was measured professionally as straight - I was told a small percentage of the K housing were poorly machined and I wanted to eliminate this variable which I did. I did all the install work myself. However, the gearbox was done at Bob's after I took it out to the tune of $960.
Now I am back to notchy shifting after 1600 miles and with the bike when in neutral with the clutch out it sounds like it did before - typical "I need my splines lubed" clatter which considering I used the right lube (Starbaurags PTSM) and it was done it should be I should not have that trouble.
But there is a bigger problem...
Here is the scenario:
1. When downshifting under power to pass someone it seems to be fine
2. When downshifting under trailing throttle - unless I blip the throttle - it acts like it is locked in gear. This happens in 3rd, 4th and 5th gear almost every time unless the RPMs drop below 2k. It doesn't do it every time but is growing more and more frequent.
3. The bike shifts up and down through all gears fine in neutral with the engine running and the clutch in.
Clutch adjustment is to factory spec for cable length at the clutch arm and lever free play is correct.
When I replaced the gear box I did not replace the entire clutch, I replaced the clutch disk only. Is there any reason that the cover, spring and pressure plate would make this happen? (The cover and pressure plate were all in excellent condition.) Is there anything else that could cause the troubles?
What could possibly be the problem... as in my eyes the only thing that could cause this is the clutch.
I am at a loss.
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(http://i278.photobucket.com/albums/kk91/electro_handyman/Bike%20Tech/K-BikeClutch.jpg)
I'd be suspect of parts #4 and/or #6 personally, but you said that they looked good, so I don't know what else could be causing the friction disk #5 to be wanting to turn with the clutch pulled in.
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Apppears to be clutch drag of some sort but what puzzles me is "Now I am back to notchy shifting after 1600 miles " Surely if pressure plate/cover issue(warp or whatever) it should have shown straight away not waited 1600ml?
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When the clutch went back together, did you lubricate part #2 with Starburgs? That spacer needs lube for smoothness of the clutch action.
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I can't find my original post about it, but same thing happened to me.
If you remove the two bolts that mount the frame to the transmission housing, is there a gap in between the frame and housing? My frame was bent enough so that I couldn't slip a piece of paper in between the housing and frame on the starboard side. I heat tweaked it until there was "paper clearance" and it took me from 8k mile spline lubes to "I didn't do one for 15k miles and I just felt guilty enough that I had to do one."