Things were going good until....

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dirtymartini

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Oct 23, 2011
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I took my '75 out for an 80 mile ride, it ran beautiful, what a nice ride I had. I came back and jumped on the '69 "S" and as I was coming back home I was coming around the lake, around a nice sweeping right hander. I accelerated, shifted to third and BANG! the engine revved and forward motion consisted of coasting along. Lucky for me my neighbor came along after I had pushed about a hundred feet. I hooked up my trailer and went back and picked it up.

Here is what I found when I pulled the primary off.

Things were going good until....
 
I know what a dirty martini is... make mine Sapphire!

but wtf came outta your primary? broken belt?
 
The spring clip that holds the clutch in :cry:

I thought that was all that was wrong. I found a clip in my boxes of spare parts, put it all back together and now when I try to kick it over I can feel something slipping/grinding when I push the kick start lever down. Anybody have any guesses what might have happened? I guess I will be pulling the gearbox apart tomorrow?
 
Possibly the clutch location circlip on the mainshaft behind the clutch assembly has broken?
 
No - the small circlip is behind the clutch center and maybe some shims. You just have to pull the primary drive off and look on the mainshaft behind the clutch. It is pretty wimpy.
 
Dirty
You don't have to pull the primary inner cover off to get at the small clip. just when you re-install use only 35-40 lbs ft. on the torque wrench.
CNN
 
batrider said:
No - the small circlip is behind the clutch center and maybe some shims. You just have to pull the primary drive off and look on the mainshaft behind the clutch. It is pretty wimpy.
Click to expand...


Thanks Russ. I thought I was going to get out of this easy...The noise does sound like it is coming from the clutch area, behind the the clutch hub. If I remember right the engine sprocket and clutch hub with primamry chain all come out together? I'm going to the garage in a few minutes to start on it.
 
yep, with that circlip off, the clutch basket assembly can push right into the backside of the primary and make graunchy sounds.
 
If he's lucky, the clip just wound itself out and everything in the clutch basket is now loose. Then he has to figure out why. It can be easy not to seat the spring good.

Dave
69S
 
Well I just finished getting the clutch hub out...the engine sprocket was really stuck. I bent the cheapo Norton sprocket puller, can't remember where I bought it.

Things were going good until....


I'm glad I I kept some tools from when I was a Mac Tools dealer years ago...it came in handy.

Things were going good until....


Unfortunately, The clutch locating circlip is there, I cant' see any problems with the clutch hub bearing....anybody have any more Ideas? As long as I'm in this far I might as well replace these seals.

Things were going good until....


Things were going good until....
 
As common sense as it is to just consider what obviously broke in primary, one must not forget that there is a nut on the other side of the main shaft that can back off and relieve spring tension also, so may be deeper issue than just the clutch nut over tightened.
 
If that circlip is OK, the clutch nut was not overtightened. I bet the retainer spring just came out, if you don't see any other damage. If the nut on the timing side in the gearbox is loose, I think the clutch won't operate right, or that shaft will move around? If you put a new spring on the clutch basket, and everything works good you may be good to go. Depends on whether you want to pull the gearbox covers off or not. Might be worth a look if you've got the inclination.

Yeah, 40 ft/lb on the clutch nut with blue locktite.

I always use heat from the ray gun on the drive sprocket, that helps it come off.

Dave
69S
 
When my mainshaft TS nut backs off the clutch lever didn't fully loosen plates d/t shaft just moving instead of plates so as Dave says first hint ain't spring clip chewing up but draging clutch and difficult to impossible shifts. But now I think on it, seems TS nut was found loose, after too tight or not tight enough clutch end nut nip ups on my own learning curve balls. You can just tug on exposed main shaft to get sense of its security w/o opening outer cover.

Check the clutch groove ain't chewed up to retain the spring clip again.
 
DogT said:
If that circlip is OK, the clutch nut was not overtightened. I bet the retainer spring just came out, if you don't see any other damage. If the nut on the timing side in the gearbox is loose, I think the clutch won't operate right, or that shaft will move around? If you put a new spring on the clutch basket, and everything works good you may be good to go. Depends on whether you want to pull the gearbox covers off or not. Might be worth a look if you've got the inclination.

Yeah, 40 ft/lb on the clutch nut with blue locktite.

I always use heat from the ray gun on the drive sprocket, that helps it come off.

Dave
69S
Click to expand...


I had the clutch all back together once and when I went to kick it over the kicker would slip and I would hear something grind part way throught the kick. It was more of a finer sounding grind...almost like some kind of splines slipping. I just tried kicking it while putting some pressure on the rear wheel (it's up on the centerstand) and I couldn't force it to slip??? Maybe I wasn't getting enough pressure holding the rear wheel back? I was ready to rip into the gear box, but it seems to shift smoothly through the gears statically, no unusual noises.
When I first took the primamry cover off the primary chain was banjo tight :shock: I think I am going to replace the clutch hub bearing, it feels a little notchy.
 
hobot said:
When my mainshaft TS nut
d/t shaft

You can just tug on exposed main shaft to get sense of its security w/o opening outer cover.

Check the clutch groove ain't chewed up to retain the spring clip again.
Click to expand...


TS nut?
d/t shaft?

I did try sliding the exposed mainshaft, it seems secure, just the tiniest bit of axial movement. The groove for the retaing spring clip looks good also.
 
If your primary chain was that tight, I'm surprised you could shift at all. Like hobot says, keep that thing loose, 3/8" SLACK, not pushing on it. I bet the retaining spring just wasn't seated properly. How's your clutch pack height while you're at it? The clutch hub bearing will take up some of that clutch wobble too, but it's only wobbly when you pull in the clutch, when it's engaged, it's irrelevant, it's sort of like a throw-out bearing.

Dave
69S
 
When I first took the primamry cover off the primary chain was banjo tight :shock:
Click to expand...

Things were going good until....


OH NO i can grantee your whole power unit is now injured from crank shaft to main shaft and all the bearing and bush supports in between. You can patch the obvious now and ride a bit then have to fix some show stopper away from home, again and again, in sequence of next least injured item giving up or bite the bullet and measure crank run out and go completely through the gear box, listing what you find for our sadistic pleasure side. This is not speculation, if your bike was ridden even once and finding banjo tight primary when cold. OH NO UGH-LY!
 
DogT said:
If your primary chain was that tight, I'm surprised you could shift at all. Like hobot says, keep that thing loose, 3/8" SLACK, not pushing on it. I bet the retaining spring just wasn't seated properly. How's your clutch pack height while you're at it? The clutch hub bearing will take up some of that clutch wobble too, but it's only wobbly when you pull in the clutch, when it's engaged, it's irrelevant, it's sort of like a throw-out bearing.

Dave
69S
Click to expand...


Well I was the last one in there to mess with the retaining spring :oops:

I was reading about the whole clutch pack height in the INOA Tech Digest. I found an old steel clutch plate that measured around .080 and that brought the stack just flush with the grooved part of the clutch hub. (This was after my retaining spring debacle) What a difference in the clutch pull! I put it all back together and that's when I had the grinding noise kicking it over. Just to be on the safe side I took the extra plate back off, re-assembled and still had the noise.

One thing I just though of was when I first started into this after the retaing spring let loose was I loosened my primary chain up because it was way too tight. Do you think it could be loose enough to be rubbing inside the primary when I kicked it over???
 
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