My new project Sierra T-Boss

[Big Sal]

I decided to drop a call to Quality Drive Systems in California....real nice guys....they took the time to look at the video and figure out what I had, and this is what he came up with.... it's a modified older 44 series Comet clutch (he said another name but I don't remember it...lol) that has had the cam modified on it to work with the way the drive system was designed, because it was likely fabricated 30+ years ago, that explains why the clutch was modified the way it was, he said that nothing was available on the market to function in that way, so the PO modded it to work the way he needed it to.

The extention shaft setup was also discussed and he said it was a better setup than factory, and here is why.... because the twin pillow blocks supporting the extention shaft/clutch setup for input on the trans the design takes all the stress off the transmission input shaft bearing and eliminates any of the "flex" in the CVT system itself, so there is no load on the trans from the clutch system, plus since there is no flex, the clutches actually work better and eliminate any slip from the flexing of the system.

The coupler was next up....it is known as a "flex coupler" and is still used in industrial applications today, and will take a lot of abuse, and is good for what I'm doing.

The setup the way it is, I was told, is well engineered and will work just fine...he did suggest I change the clutch over to a larger diameter and wider to closer match the factory clutch on my engine and also to put the fixed sheath on the correct side...the floating clutch was ok too...it was done that way to center the belt....the previous owner must of been a pretty clever guy...lol...anyway...the clutch I need is available...clutch and belt are gonna run me right around $300...not bad for a good solid system in my toy...she was well worth the $300 I paid for her...thank god....I was starting to get worried...lol

[thebuggyman1]

Best of luck
I always overthink and overresearch everything.....never trust things till I think understand it.....

[Big Sal]

I'm the same way...hence the phone call....lol...now I know where I stand...the reason also for the driven clutch change is because mine is a one off design, if I ever needed to service it the parts would have to be modded to work if I could even find them, and the clutch is a bit of an oddball because it has a 3/4 inch shaft instead of 7/8...changing the clutch to a newer version will allow me to use a modern belt and be able to get repair parts easier...but the system would work fine as it is...what are you guys opinion of a larger diameter/wider clutch, is it better? I'm worried about if there is enough room between the pillow blocks for a wider clutch to be able to spread out thru it's entire range of movement...the width of the space between the clutch plates that important? The factory Arctic Cat clutch on the 440 is wider than the driven is....I figured the primary had to be a bit wider so the belt could "free wheel" on it and would engage when the RPM's were higher rather than engaging just off idle.

[thebuggyman1]

The dia. of the driven means everything to gear ratio. A larger dia. means more low end grunt. Belt width ....a 1 3/16" or 1 1/4" wide belt is common and will give many more choices than the 7/8" wide that the 40 series takes. Plus you are limited to a 40 series drive also.
I'm going to suggest again that you ditch the Idler shaft setup and return to the normal t-20 mounted clutch. Roy does not understand how robust a t-20 is.....the input shaft bearing is NOT a common problem....the only common problem they have is "owner abuse" lack of fluid changes and improper storage (water intake) and such.
A used secondary will save you money......and a belt off ebay probably will too. I paid $20 + $10 shipping on the last one I bought.
Clutches are made to use a specific width belt......You can often alter them a little, but only a little. If you use a primary made for a 1 3/16", and a secondary made for a 7/8", the belt would have to be 7/8" and the primary wouldnt engage till you were at 4000RPM (guess).
Now there's an idea for Don's new racer.

[Bazooo guy]

We used that type of chain coupling more than 20 years ago....they work well till the chain wears.
A good upgrade is a nylicon coupling....they last forever and are maintenance free.
Nylicon Gear Coupling

[Big Sal]

I have 3 snowmobiles that I purchased as a lot to get the engines...all of them have 440's in them....could I use the driven clutch off one of the sleds? Centering the trans is a great idea...but the whole drivetrain/controls and chassis layout would have to be totally reworked to make it happen, I've never done anything like that before, I'm not sure I can undertake a project like that, my modding skills leave a lot to be desired....

[amphibious drew]

Its really not that compllicated. A weld shop or fab shop could probably put your frame right for it for you, but a case of beer and a buddy could do the same. I would personally just take some measurements and post a want ad for a max II or attex frame that you could chop and fit. I like my sticks in the middle as i can put a kid on either side of me, but bending them over to the side should be pretty simply if thats what you want.

[Big Sal]

Problem is the darn thing has two "bucket" seats molded into the body with a hump between them...so the sticks have to be on one side or the other...I think I'd have an easier time finding a roller machine that needs a trans and an engine that had the T-20 in it originally...lol...I could muddle my way thru this....but I was looking for a rider project rather than a "re engineering 101" project....if anything with what I have invested I've got a killer engine/trans combo....lol

[amphibious drew]

You know, you are right. You could cut the seat and put a bench in, but I have seen several max IV's out there missing the engine and transmision for not more than a couple houndred bucks lately. I bet if you do some searching you could get one of them.

[Big Sal]

I was looking for another Attex and came across this...lol