MOTOBRICK.COM

TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: chacal on June 08, 2015, 07:38:48 AM

Title: Clutch won't disengage during deceleration
Post by: chacal on June 08, 2015, 07:38:48 AM

I recently purchased a 93 K75S with ~24K miles. After an ~1.5K highway trip, I noticed that the clutch does not fully disengage when I am decelerating with the throttle either closed or nearly closed.  The clutch will immediately disengage when I blip the throttle, and it will disengage at any other time.  Based on reading the other posts, it sounds like this might be a symptom of needing a spline lubrication.  Is that a correct assessment?  Is there other maintenance work and/or checks I should perform at the same time?
Sorry if this is duplicating another post; I couldn't find anything else with quite the same symptoms.

Thank you.

Title: Re: Clutch won't disengage during deceleration
Post by: TimTyler on June 08, 2015, 09:59:03 AM

Quote from: chacal on June 08, 2015, 07:38:48 AM

... it sounds like this might be a symptom of needing a spline lubrication.

That's my guess. Specifically a "clutch spline lube."

Title: Re: Clutch won't disengage during deceleration
Post by: chacal on June 08, 2015, 10:42:26 AM

Thank you.   I shall do that.

Title: Re: Clutch won't disengage during deceleration
Post by: Motorhobo on June 08, 2015, 12:43:50 PM

I've had the same symptom for a long time even after the clutch spline lube and I brought it up at least once in related threads like this one --

http://www.motobrick.com/index.php/topic,5768.msg37287.html#msg37287

What it feels like to me is as if the clutch spring didn't have enough tension to disengage the friction disk from the pressure plate. So it stays partially engaged at idle until you give it a nudge with the little throttle blip you mentioned.

I don't know if there's a way to test the tension produced by the spring short of replacing it. Someone mentioned that the compression ring (#2 on http://store.bobsbmw.com/microfiche/DisplayImage.aspx?Size=Full&Type=Z&ImageID=2820 (http://store.bobsbmw.com/microfiche/DisplayImage.aspx?Size=Full&Type=Z&ImageID=2820)) can flatten out which may cause this, but last time I did the clutch spline lube I inspected it and it looked fine.

So -- I have it too. If you're going to get in there soon, maybe think about talking to a dealer and asking whether the spring could be the cause. If so, let me know...I'm due for a clutch spline lube in a few months.