Primary clutch issues?

cbc24

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Hey friends, I have seen over the course of last winter a handful of Primary clutches explode on the 18+ ctech Arctic cats. Has anyone else had this issue? it looks like the outer sheeve is too thin and cracks near the center. Wondering if this is a common thing among everyone or just aggressive riders.
 

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kanedog

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Last year while checking the full shift out clutch action, I discovered the cover bushing prevents the clutch from fully closing at or near full shift out. The bushing stops the shift out and the force of the weights trying to close the clutch puts tremendous strain on the cover and sheave. It is effectively pulling the cover and moveable apart with incredible force. Over time, the components may flex and weaken with each full shift out so the clutch may not fail immediately. At some point, the metal will be fatigued from 💪 flexing and eventually the cover and/or sheave would likely fail. At 8000rpm, a single failure point on the cover or sheave would likely result in a catastrophic failure. The speed in which pieces can be projected are quite high.
I would suspect the clutch failure to happen more in the flatland riding areas where the clutch is more likely to reach overdrive and full shift out. In the mountains and tree riding, the riding is slower and clutch loading is more. Most mountain riders won’t even see 1-1 ratio as the sled is geared for a 72mph at 1-1. Most mountain riders never see 65 mph. There may be less failures in the mountain regions.
There is about a .060” gap when the Team clutch is fully shifted out. Normally, the two clutch sheaves butted against each other are what stops the shifting at full shift out. The load is taken by the beefy spider. But not on the Team clutch. The cover is stopping full shift out and taking all the load.
I’m surprised this got by the clutching dept. and quality control. But then Team isn’t exactly known for quality either.
Anyhoo, Textron I am available to develop a better clutching system with you. It can easily be done cheaper and better than the current system. There are just too many moving parts and the sloppy tolerances combined is wearing the components too quickly. This affects performance, reliability and in in some cases, causes liability. Even if the tolerances were tightened up, the many moving pieces would likely bind. There already is major binding in the secondary with loose tolerances. Yes, people say that this clutch system is the best yet. It can be so much better though.
You can send the Textron Clutch guy up to R and D with me as we can tune up to July. I have built the combination that will put Cat in front for at least seven years with no motor modifications. Come and check it out. The Alpha clutching and a couple other things are leaving about 30% performance on the table.
I’m not being a smart ass but how many high paid engineers and multi million dollar suppliers missed the clutch cover issue? It’s kinda basic clutch knowledge is why I ask. How did this liability issue get past Team industries? How much has it cost Textron? How much will it cost Textron?
I’m in western Canada 🇨🇦 and I work for free. I don’t want any money or anything. I don’t have anything to sell and I have no alterior motive except to make Cat lead by a long shot. Let’s do this.
The above are my beliefs.

w. A41A029B-028E-4460-AA6E-A1702650FCD0.png0A65D57D-F63A-4A30-BAA4-CF8D86A95519.png
 
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kiliki

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Had one leg of the spider break off at 1k miles. Was at 8k rpm and was lucky to have it hit the support piece of the front of the running board and not go out of the body. broke my cpc adjustable right in half.
Just put on my second belt of the year and cat cover the belt.cpc.jpegcat spider.jpeg
 
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kanedog

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Had one leg of the spider break off at 1k miles. Was at 8k rpm and was lucky to have it hit the support piece of the front of the running board and not go out of the body. broke my cpc adjustable right in half.
Just put on my second belt of the year and cat cover the belt.View attachment 333841View attachment 333842
Oh my. That’s some carnage. What do you think caused it?
I notice the aftermarket weight broke in half and the belt is new. I can see where it started and then boom! She let go. The weight wasn’t riding square on the roller. You would think that the weight would wear itself in and be square with the roller after 1000miles. I wonder if the weight pin hole won’t wear in because it’s so wide. And there are two pretty thick spacers on each side so the twisting load is also absorbed by the spacers and sides of the weight area. It wouldn’t ever wear crooked. But if the spider tolerance if off, it could put different pressure on different places and not spreading out the load evenly. Add in a stiff primary spring, heavy weights and some vibration spells trouble. Hmmmm. Why is there a ring replacing the starter ring? Just thinking out loud. A possible Kanedog investigation may occur.
 
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ak

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I’m assuming the ring gear is a harmonic balancer of some sort? Speedwerx is removing them for weight savings now.
 

sno*jet

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I've cracked some p-85s but not the team yet. I did notice the spring was showing signs of binding on the cover so I installed a glide washer there. engagement actually went down. ill install one on the other side too next time I'm in there. '17 clutch.
 

Fredrik

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Checked my primary it can get full shift
sheaves touch before inside cover bushing touch spider nut
i have machined down stock spider shim to 1,5mm stock is 3mm
nut and spider thread are level
also cluth springs should be centered on inside diameter so they can grow when compressed.
 

Wheel House Motorsports

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Seen multiple riders blow arpart multiple primaries. It is a fixed group of riders all with similar riding style. Given Kanedog's example it makes good sense. All of them do lots of whips/reentries and are WOT updside down in the air so im assuming full shift is being hit FAR more often then any normal mtn sled. Tons of unloaded WOT air miles would do it!
 

kanedog

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I have two Team primaries on hand. I only checked one so I will go check the another one. Stand by.
 

summ8rmk

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Would an aftermarket billet cover on The primary be more durable than the stock cover?

Sent it
 

kanedog

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Would an aftermarket billet cover on The primary be more durable than the stock cover?

Sent it
100% stronger. The stock cover is kinda wimpy. I ran the 911 cover on my Alpha. It’s stronger and has much larger bushing. Cheers
 

summ8rmk

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Glad i read this thread. I decided to thoroughly inspect my 19 primary...
And 2 cracks on the cover...

Now, to decide which aftermarket cover to go with.....?

And keep stock weights or, MDS....?


Sent it
 

kanedog

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Holy crap. Great find!
 

boondocker97

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Now...are those cracks from the towers trying to spread under load, or from the cover not being totally centered when installed and popped on the edge when the bolts where tightened down?
 

summ8rmk

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Now...are those cracks from the towers trying to spread under load, or from the cover not being totally centered when installed and popped on the edge when the bolts where tightened down?
Definitely could be from install. This is the first time i have touched the clutch since i picked up the sled from the dealer.
Where the face of the cover meets the tower show zero wear/movement....


Sent it
 

kanedog

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Now...are those cracks from the towers trying to spread under load, or from the cover not being totally centered when installed and popped on the edge when the bolts where tightened down?
I’d say with the cover bushing interference the cracks are from the cover flexing. Picture the moveable sheave towers pulling on the cover as the bushing is hitting the spider nut. It’s pulling on the outside of the cover. It’d be flexing each time the clutch hits full shift out. Hope that makes sense,
Note-This is a fine example of drunk posting. I’m gonna leave this up as a reminder to myself to not drink and post. On second thought, I read it again and it’s pretty mean spirited. I’m gonna delete some of it. Haha

The above are my beliefs.
 
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boondocker97

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No worries. I should have clarified I meant to say incorrectly assembled at cat, not by summ8rmk. I got a used factory takeoff clutch that had the same cracks. Looked to me like the greatest care wasn't taken with assembly at the factory. One edge of the cover wasn't quite seated down all the way and had an aluminum chip sandwiched between it and the tower that chipped off. I cleaned it up and I've been running it for 500 miles so far. With how tight the cover fits I could see the average person having this happen by mistake if they use the bolts to suck the cover down into place without it being seated first.

I have three of these clutches including the one on my sled. One of them is very early build (dec2016) and doesn't have the shim under the spider. Believe this is the trail sled setup? The sheaves will touch on it. The other one not on my sled has the shim and the sheaves have a gap with the cover bushing bottoming out.
 
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