Scrap it or rebuild it?

[Jeevesso]

I have an old primary Polaris clutch on a '92 Indy Sport.

I just took it off, thinking it might need some TLC, and found it is horribly worn.... weight holes, pins, buttons, bushings.

These are all theoretically fixable, but the thing I am not sure about is what appears to be fine hairline cracks on the outer cover plate.

Could some of you with experience in these please advise whether or not I should proceed with a rebuild, or just scrap and buy new...

Please feel free to weigh in... are the lines in the pic cracks, or some kind of casting residue...

 

[yz400ex]

They are probably just casting marks, but might be cracks. I have quite a few primaries from different years laying around and they all have casting marks on them somewhere. If you determine that they are cracks and need a cover, let me know and I will see if I have one I could send to you. Also, be sure to check the fixed sheave for cracks on the face of it near center. That's the most common place to find cracks on a primary.

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[LoudHandle]

From the photo, my guess is cracks as they originate and end at the bolt holes. Likely a badly worn cover bushing and it was causing the cover to flex and hammer under use. the only sure way to tell the difference is to die penetrant test the cover, if the die leaches back out when the developer is applied, they are indeed cracks. If you were closer I could do it for free, but and reputable welding or machine shop should have a PT kit to do that. Guessing with shop rate and time, $20-$40 to confirm or deny my suspicions.

 

[Jeevesso]

Here's hoping you're right...

They are probably just casting marks, but might be cracks. I have quite a few primaries from different years laying around and they all have casting marks on them somewhere. If you determine that they are cracks and need a cover, let me know and I will see if I have one I could send to you. Also, be sure to check the fixed sheave for cracks on the face of it near center. That's the most common place to find cracks on a primary.

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YZ...Thanks for giving me some hope. I have heard that clutches run as much as $700 up here in Canada. (Ouch)... I don't think my sled is worth that much.
I am just trying to fix the sled up so I and my grandsons can bomb around a bit. Love to get the lads sparked ...

I will check further, but I do know that the fixed sheave is immaculate.

As far as replacing the cover plate, I wasn't aware that you could do that without upsetting the balance to the primary... I sure hope that is an option, and I sure do appreciate your offer!

 

[Jeevesso]

From the photo, my guess is cracks as they originate and end at the bolt holes. Likely a badly worn cover bushing and it was causing the cover to flex and hammer under use. the only sure way to tell the difference is to die penetrant test the cover, if the die leaches back out when the developer is applied, they are indeed cracks. If you were closer I could do it for free, but and reputable welding or machine shop should have a PT kit to do that. Guessing with shop rate and time, $20-$40 to confirm or deny my suspicions.

Thanks for your response, LoudH. Sounds like a great idea to get it tested before I over-react. Do you know if dealers/repair places have the kits to check? It would seem that to be safe they should check 'cracks' out before any rebuilds...

BTW, if worn cover bushings are the cause of the cracks, the bushing on this primary qualifies. I can easily slide in a piece of paper!

 

[Jeevesso]

I went to our local Poo dealer to get their opinion about my primary clutch.

and got good news and bad news...

The good news is the cover lines/marks are not cracks.

The bad news is that the cost of rebuild is prohibitive. (apparently each worn weight carved away some of the side of the spider, so not only would it need a complete spider rebuild kit, but should probably be re-balanced too)



My only hope at this point is to find a good used clutch from some dead sled yard... more bad news is that I have NO clue which primaries are interchangeable from models and years.

Or buy some clutch tools

or walk away from the sled.

Ideas? '92 Indy Sport 440

 

[yz400ex]

I probably have a spider for that clutch that would get ya by also. I know how being on a budget can be.. I have been on one for a long time now. If I have the parts for you I could send them to you for just the cost of shipping if that would help.

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[LoudHandle]

I'll look thru my shed as well, I likely have one that would work. Most of mine are a bit newer and likely are set up to run the wider belts but could be re-shimmed for that era of machine. Same deal would apply, you cover postage and it's yours. I'll check the online fiche and verify a few things before hand. If you have the belt number and width that the sled runs, clutch bolt size, etc. It would narrow my search a bit. You can PM the particulars and we can work it from there. As I'll never run them again some one might as well get some use out of them, and it may as well be the next generation of Burandt's.

 

[Jeevesso]

LoudH and yz...
Guys, I sure do appreciate your suggestions, advice and offers of spider help. At this point I am first going to find out what there is locally. Your respective offers of replacement spiders would work in a pinch and are much appreciated but I'm going to try to get a complete functional used primary. If I got a spider from either of you gentlemen, not only would it break up your perfectly good balanced sets, but when I installed it/them in my drive, I would need to have the unit re-balanced. I have heard that balancing runs ~ $110. Everything up here to do with sleds is expensive! I guess nobody wants to work for free. Imagine.

What do you think of another option, if I can't find a local, intact, used replacement... grinding down my spider with a dremel, and removing an equivalent amount of metal from each of the 3 legs to approximate metal worn from the worst leg...? Kind of evening up the wear to restore the balance.

This is such a low HP/rpm application it shouldn't create significant vibration. The manual says operating rpm is 6500... I presume that is WOT. Pretty low compared to today's speeds.

Before I removed the clutch and started cleaning it up, there was no indication of imbalance, slipping, heat or mis-function, so the spider wear couldn't have put it out of balance that much...

Or I could be full of crap.

Thoughts on any of this...?

 

[LoudHandle]

My offer was for a whole clutch. But considering the sled, RPM, etc. I would be comfortable running the existing clutch with the spider deburred (not trying to guess balance, as long as the wear to the spider is reasonably even from the three weights). I would replace the bushings, the buttons, as well as the weights (or rebushing them at a minimum). Back in that day they balanced them far better at the factory than they do today, and even with the wear it is likely still within the currently loose factory standard. If you can get the rebuild kit and locate a friend in your area with the clutch tools, I would lean that way. Someone would likely do a beer trade for tool time.

If not one of my newer clutches may be able to be narrowed up enough to work, without remachineing things. FWIW

 

[yz400ex]

I agree with LH 100%. I wouldnt worry about having it rebalanced.. For what you have and what it will be used for, I just dont see it being necessary. I have owned a LOT of sleds in my life, most of them when I was much younger and 99.9% of those were old sleds with small motors. I never worried about having a balanced clutch or running pretty worn out parts. If you arent going way back in the back country or far from home or anything I wouldnt bother with putting much money into the clutch on the sled. Sounds like your grandkids just ride around near the house or get pulled in a sled or something behind it.. The clutch you have, in its current condition will get you by for a long long time.. If you do feel like you need to replace parts or the entire clutch, feel free to let me and/or LH know and we will get you the parts/whole clutch you need to ease your mind, but regardless of the route you take, I wouldnt worry about the clutch being balanced after you are done.. Just let me know if you need any parts.. I have a bunch of old clutches that have been parted out to use the parts on others so you wouldnt be breaking up a complete clutch.. No worries about that.. Whatever you decide, just let me know if you ever need the parts.. Even years down the road.. The offer for you will always be on the table!!

 

[volcano buster]

If you clean yours up, you can re-bush the weights and add Comet weight shims to keep the weight from rubbing against the mount some more. This will help take some slop out and center the weight.

Those items aren't too expensive or hard to change out so it might help the clutch work better given the rest of the wear.

 

[Jeevesso]

My offer was for a whole clutch. But considering the sled, RPM, etc. I would be comfortable running the existing clutch with the spider deburred (not trying to guess balance, as long as the wear to the spider is reasonably even from the three weights). I would replace the bushings, the buttons, as well as the weights (or rebushing them at a minimum). Back in that day they balanced them far better at the factory than they do today, and even with the wear it is likely still within the currently loose factory standard. If you can get the rebuild kit and locate a friend in your area with the clutch tools, I would lean that way. Someone would likely do a beer trade for tool time.

If not one of my newer clutches may be able to be narrowed up enough to work, without remachineing things. FWIW

Loud: I thought your offer of a spider was generous, the offer of a clutch is more than I could accept in good conscience, but again thanks for the offer.

Like you say, evening up the spider wear on my own clutch is probably the most cost effective way to go.

Can you recommend a good source for buttons, weights, rollers, pins, bushings etc.?
Or should I just stay with OEM?

I guess I may as well start looking at non-OEM clutch tools (cheaper, I'm hoping)... may as well bite the bullet and be the friend who gets the beer.

 

[Jeevesso]

I agree with LH 100%. I wouldnt worry about having it rebalanced.. For what you have and what it will be used for, I just dont see it being necessary. I have owned a LOT of sleds in my life, most of them when I was much younger and 99.9% of those were old sleds with small motors. I never worried about having a balanced clutch or running pretty worn out parts. If you arent going way back in the back country or far from home or anything I wouldnt bother with putting much money into the clutch on the sled. Sounds like your grandkids just ride around near the house or get pulled in a sled or something behind it.. The clutch you have, in its current condition will get you by for a long long time.. If you do feel like you need to replace parts or the entire clutch, feel free to let me and/or LH know and we will get you the parts/whole clutch you need to ease your mind, but regardless of the route you take, I wouldnt worry about the clutch being balanced after you are done.. Just let me know if you need any parts.. I have a bunch of old clutches that have been parted out to use the parts on others so you wouldnt be breaking up a complete clutch.. No worries about that.. Whatever you decide, just let me know if you ever need the parts.. Even years down the road.. The offer for you will always be on the table!!

yz: You and loud are spot on and I agree totally. It's an old sled, not worth much. Won't go too fast, but can still be tons of fun to a 15 year old, (who incidentally was over last night, checking out old 'Sport' and telling me he can't wait)

In the meantime, his grandpa will have to get his butt movin' on this project.

Thanks for the advice and kind offers yz. Much appreciated!
ps.. I may ask for some technical expertise as I start working on the rebuild. Stay tuned!

 

[Jeevesso]

If you clean yours up, you can re-bush the weights and add Comet weight shims to keep the weight from rubbing against the mount some more. This will help take some slop out and center the weight.

Those items aren't too expensive or hard to change out so it might help the clutch work better given the rest of the wear.

Volcano... Thanks for the tip. I haven't torn down the spider, yet, but I'm pretty sure you are correct when you say I'll need to shim up the new weights. Are the Comet shims better/different from Polaris?

The part I'm not looking forward to is the spider removal. I probably wouldn't remove the spider, except 1 of the 3 rollers is sloppy.

 

[Jeevesso]

Spider worn

Well I got my tools, weights, & shims. Took the cover off and had another look without the spring and weights in the way.

A closer look at the 'legs' reveals that one is horribly worn; the weight pin must have been so worn that even the pin holes in that leg are so elongated that shimming out the weight is tough. The meat removed from that leg is so deep that there is no way I would want to grind away an equivalent amount from the other legs to even up the balance. It would weaken the spider too much.

And because the pin hole is ovalled, I don't think I would waste my or anyone else's time trying to balance the clutch.

The best I can hope for is to put it back together and see how it runs.

If it shakes the S out of the machine, I'll have my answer...

 

[Jeevesso]

It's Alive!

I finally had time to give the clutch / sled a tryout today in the back alley.

Just quickly up and back and around a bit to test the engagement. Smooth. No sticking, so far.

Minimal shaking.

I'll have to keep an eye on it and keep it clean... check to see if it is overheating and how the belt is functioning.
I suppose I should have a look at the secondary too, but at this point I kinda feel like if it works, don't F with it.

It seems my fears about the imbalance were unfounded; the Indy with its new clutch weights and shims works great!

Many thanks to all who offered advice and got me through this 'adventure'.