Comet Driven Sheave

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awerder
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Real Name: Andy
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Comet Driven Sheave

Post by awerder »

Can anyone identify this secondary clutch model and tell me how to disassemble? I need the change the buttons but can't find any instructions.
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awerder
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Re: Comet Driven Sheave

Post by awerder »

Came from '76 400. Primary clutch is Comet 102C.
rminier
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Re: Comet Driven Sheave

Post by rminier »

Click on this link to the vintagesnow site and you will have the full service manual, which includes the info you need.
Even though this manual shows a print date of Aug. 1977, it includes info on the '76 models.

http://www.vintagesnow.com/John_Deere_f ... one_SM.pdf
75 Sno Jet Astro SS; 79 Kawasaki Invader 440 (two of them); 81 Scorpion Sidewinder; 82 Blizzard 9500; 83 Yamaha Vmax 540; 97 MXZ 670; and holding.....for now.
awerder
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Re: Comet Driven Sheave

Post by awerder »

Info for this particular sheave was actually found in the '75 service manual for the 00/JDX series. It has the two half moon clips and is different from the Cyclone Sheave and the one shown in the '76 manual.

What I encountered were burs/ridges on the shaft teeth above the clips, presumably caused by metal on metal contact. With some effort, I was able to remove the clips but the burs prevented the helix from coming off. To fix this, I put one clip back in to hold the helix down, then carefully ground the burs off with a dremel tool and a tiny grinding cone. I ground one half, spun the clip around, then ground the other half. This allowed the helix to come off. Once the helix was off, I carefully ground and sanded the remaining burs, replaced the buttons and put the thing back together.

Took more time to figure out what was wrong than it took to actually fix it.
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jep_800
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Re: Comet Driven Sheave

Post by jep_800 »

Andrew, When you had the sheaves apart, did you inspect the hub bushing (M64611)? You can find those fairly easily, and I've replaced them on both my sleds, just cause I figure if I had it apart, might as well replace as many parts that can be. It's key to place anti-seize grease on the hub where the bushing goes so the clutch does not bind on engagement. Also, an NOS red spring can be found as well without much trouble (M64609).
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1975 John Deere 800
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
awerder
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Re: Comet Driven Sheave

Post by awerder »

I inspected the bushing exterior for wear, pitting, scoring, etc,. but I didn't it from the moveable face. Is it supposed to come off easily? Any recommendations for anti-sieze grease?
awerder
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Re: Comet Driven Sheave

Post by awerder »

Didn't remove the bushing.
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jep_800
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Re: Comet Driven Sheave

Post by jep_800 »

Mine typically slid right off, but I know some can be stubborn. If there wasn't much wear in the bushing, you're probably fine. If you do try remove it, maybe a little heat on the hub would help, and tap on it with a mallet.... should break loose.

I just bought a tube of Permatex Anti-Seize that I use when I've worked on these.
1975 John Deere 800
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
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JoeRainville
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Re: Comet Driven Sheave

Post by JoeRainville »

Andrew, I literally have a case of those bushing, several of the cams, and might even have a spring. I also have clips, all new in the bag (NIB) new old stock parts (NOS) if you need them.

I don't think I have the plastic siders, but I think they are available elsewhere.

-Joe Rainville
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Chuck Norris doesn't get frost bite. He bites the frost.
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jep_800
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Re: Comet Driven Sheave

Post by jep_800 »

Joe,

I think I got the plastic sliders from Matt (Newbreed).

Jason
1975 John Deere 800
1975 JDX8 (VC Finisher 2019)
1976 440 Cyclone (VC Finisher 2022)
1974 El Tigre 440 (Sold)
1996 Arcitc Cat 440Z
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