Gnashing of teeth

[kerryb]

My '83 aspencade is having difficulty dropping into gear. I ca n feel and hear the gear dogs banging into each other as they slide by during a shift. Of course the first step was to tighten up the clutch cable. I even took out the 1/8" of freeplay that is supposed to be at the lever...no improvement. It feels and seems like the synchronizing function is failing. I can double clutch between 1st and second, but that isn't much fun and won't work for 3rd and 4th. If I shift very carefully at 3200 rpm I can get it to go in smooth (snik!) or shift quick at the same instant I pull the clutch in at higher revs (4 to 5.5k rpm). I went looking for another clutch adjustment under the cover, but there isn't one on an '83. Downshifts are perfect and smooth under any condition. Bike has 60k miles on it, I got it at 48k miles. Is problem has been getting slowly worse for the last 5000 miles. I thought it was me at first but not so sure now.
Anybody got a clue as to whats going on? p.s. 10-40 motul or spectro oil change every fall, about 2-3 k miles per year. (I have other bikes to ride about same distance)

Could it be warped plates from pulling a trailer and beating on the clutch to get going uphill from a dead stop?
Clutch does not slip at any gear or speed unless I'm feathering it. I have the tools and experience to pull the clutch and check it, I just don't want to untill other ideas or diagnosis are tried first.

 

[Prlwng]

If bike wants to jump abit when going into first gear, would maybe be warped plates draging.

Dreading the soon to be clutch replacement on mine from heavey trailer pulling.

 

[kerryb]

Bike doesn't jump going into first at a stop. Not bothered by pulling the clutch out to inspect, but I was hoping for another adjustment. Too bad factory service manual isn't much help.
I do have the tools, made them for the last clutch job.

 

[saganaga]

Any chance of an old cable having some broken strands and stretching?

I'd check that before pulling apart the clutch.

 

[GTC@MSAC]

The way that the transmission gears connect side-to-side on the same shaft, down shifting would put pressure on the opposite side of the gear dogs on the side of the gears. This means a gear might very well be bad, but only slips or jumps under acceleration, not deceleration. I have never had this problem with any Honda, but had a 1977 Yamaha XS750 that was very torquey and was notorious for damaging the side dogs for 2nd gear. If you have not seen how the gear dogs engage, this video is a good illustration of them.

 

[kerryb]

The way that the transmission gears connect side-to-side on the same shaft, down shifting would put pressure on the opposite side of the gear dogs on the side of the gears. This means a gear might very well be bad, but only slips or jumps under acceleration, not deceleration. I have never had this problem with any Honda, but had a 1977 Yamaha XS750 that was very torquey and was notorious for damaging the side dogs for 2nd gear. If you have not seen how the gear dogs engage, this video is a good illustration of them.

That's the best video I've seen yet on how it works, thankyou. Unfortunately I'm still clueless as to what is causing my issues. Is there any other possible causes besides the clutch not fully disengaging?
I can't find a visible issue with the cable, but it wouldn't be difficult to pull it for a closer look and test.

 

[dan filipi]

Great video. Explains constant mesh transmission really well. Learn something new I did.

 

[GTC@MSAC]

That's the best video I've seen yet on how it works, thankyou. Unfortunately I'm still clueless as to what is causing my issues. Is there any other possible causes besides the clutch not fully disengaging?
I can't find a visible issue with the cable, but it wouldn't be difficult to pull it for a closer look and test.

It was meant to show you how side dogs work. Your jumping issue could very well be worn side dogs on one or more of your transmission gears, and not the clutch. You said your gears jump when up shifting, but not down shifting, correct? Each side dog pushes as you accelerate, but each gets pushed on the less worn back-edge as your rear wheel pushes on the transmission during down shifting and deceleration, and won't jump.

 

[GTC@MSAC]

A Clutch basket can wear badly and give similar symptoms. Each vane on the clutch basket also has an edge that "pushes" and an edge that is "pushed".
The clutch basket is more easily accessed than you transmission, so start by examining the clutch Basket & Hub first. During acceleration, the more worn edge is pushing the transmission shaft, making your clutch action difficult and hard to work at the lever. During deceleration, the smoother, less worn edge is being pushed, and your clutching action will be smoother.

Bottom line is that you have component wear issues, and cable adjustments aren't going to fix it.

 

[GTC@MSAC]

Watching this should help you understand how the motorcycle multi-plate works. I hope this will help.

 

[GTC@MSAC]

The clutch basket & hub wear is much more common than the gear-dog wear, especially in Hondas. So you stand a very good chance of curing it all with a clutch assy rebuild using a new basket & hub, or even a low-mileage used one, and new clutch springs.

Don't feel bad, though. My 82 Silverwing clutch is at 58K miles and acting up a little, too, so I may be doing the same myself here soon, lol!

 

[GTC@MSAC]

Great video. Explains constant mesh transmission really well. Learn something new I did.

Sometimes knowing all this is a curse, because I often can't ride without seeing all these things working in my head, lol!

 

[GTC@MSAC]

I wish these animations were around 40 years ago when I started riding & wrenching on my own bikes!

 

[kerryb]

Thanks for all the replies. This winter, I pull the motor, inspect the clutch thoroughly and find the cause. It pains me to ride it this way as I feel like I'm beating on it. This climate change thing is cutting into my wrenching season!

 

[dan filipi]

I once had the scavenger pump partially plugged so it couldn’t remove all the oil accumulated around the clutch. The result was easy shifting into first at cold start but after a few minutes riding, shifting up or down became almost impossible. First would drag heavily at a stop. May not be your issue but good thing to check that pump condition.

How I discovered this was after putting the clutch cover back on and seeing oil level was full, when clutch started to drag I saw oil level was down. Pulled the clutch cover and at least 1/2 quart drained out.
Research showed me a wet clutch is oil cooled with a shower of oil but will drag if it’s immersed in oil.

 

[Old Fogey]

As above problem:
http://wingovations.com/scavenge-pump-problem/4579471109

 

[kerryb]

Well THAT is some enlightening information. Now I have two things to check when I get inside. But before taking anything apart, when I look at the oil level window with the engine running, what would an acceptable level be?, 1/2 way up the glass, 3/4's , or pretty near the bottom as I have observed in the past?
Thanks for your help, and yes, when I riding and listening to all the little noises from the engine, I'm very busy imagining what the systems look like making the different sounds!

all part of the adventure...

 

[dan filipi]

Well THAT is some enlightening information. Now I have two things to check when I get inside. But before taking anything apart, when I look at the oil level window with the engine running, what would an acceptable level be?, 1/2 way up the glass, 3/4's , or pretty near the bottom as I have observed in the past?
Thanks for your help, and yes, when I riding and listening to all the little noises from the engine, I'm very busy imagining what the systems look like making the different sounds!

all part of the adventure...

I should have said the oil level had dropped when viewed with the engine off, not running.