TKI drive shaft fix kit

[lilduke]

Well actually the truck driveshaft slides in/out on splines so only end loaded and typically also carried by a steady bearing, not at all the same.
The sled has an uplift side load on the bottom spline, released and reloaded every time throttle applied and chopped.
Not at all the same dynamics on the spline for wear or magnifying play over time.
But I get how looking through a glass of doolaid makes things look a little murky and misrepresented........

Look at the this drive shaft. Does it look like it has a steady bearing? It moves up and down 2 ft at high speed....

I was sticking up for polaris in the muskoka thread yesterday. Now im a doolaider i guess. Or maybe you just got manure for brains


What ever

 

[snochuk]

The drive shaft is not installed yet so I wouldn't know, kinda why I said typically.
The rest rings true.
Sometimes this place is just a chit ton of fun, just keeping on the manure theme.

 

[Caper11]

When you hit a 3ft mogul at 100 mph in a 7000lbs trophy truck do you think it would put some kind of load on the drive shaft at all other than just twisting? The drive shaft cycles up and down with the axle and susupesion. You dont think that would put any kind of load on the splines of the drive shaft other than just twisting? Still talking auto drive shafts here. But no they dont have a track wrapped around them


High angle drive shaft:

View attachment 277132

its all been done before, there is 0 reason a 2 piece shaft with splines won't work on a skidoo.
other than being build too light.




Peace,

I get what you are saying, but there are different forces on a snowmobile drive shaft, vs a trophy trucks front axle drive shaft. When the trophy trucks suspension cycles that spline is designed to move in and out with the suspension travel.
A snowmobile rear suspension and track, is alot like a dirt bikes rear swing arm. As the suspension compresses, the track gets tighter, same as the chain on a dirt bike.
The spline on the doo drive shaft is seeing that cyclical side loading alot in the bumps. Too tight of a track will make that worse. The only thing holding that coupling and bearing in the chain case true, is the bearing fit, and a circlip.

It does work yep, excellent idea for guys who change tracks alot racing, is the two piece shaft a problem? Remains to be seen IMO, but what I did notice when on the trail was a new noise in the drivetrain, a growling like something was rubbing on the tunnel but nothing was, no ice build up.
I have not heard that noise yet with the one piece shaft. According to my dealer, lots of guys last year complained about that exact noise. Time will tell.


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[lilduke]

Sometimes this place is just a chit ton of fun, just keeping on the manure theme.

True, i didnt bring up the auto drive shaft. Just adding to it. But now im bored of that.


So switching it to just how chitty is artic cat

I get what you are saying, but there are different forces on a snowmobile drive shaft, vs a trophy trucks front axle drive shaft. When the trophy trucks suspension cycles that spline is designed to move in and out with the suspension travel.
A snowmobile rear suspension and track, is alot like a dirt bikes rear swing arm. As the suspension compresses, the track gets tighter, same as the chain on a dirt bike.
The spline on the doo drive shaft is seeing that cyclical side loading alot in the bumps. Too tight of a track will make that worse. The only thing holding that coupling and bearing in the chain case true, is the bearing fit, and a circlip.

It does work yep, excellent idea for guys who change tracks alot racing, is the two piece shaft a problem? Remains to be seen IMO, but what I did notice when on the trail was a new noise in the drivetrain, a growling like something was rubbing on the tunnel but nothing was, no ice build up.
I have not heard that noise yet with the one piece shaft. According to my dealer, lots of guys last year complained about that exact noise. Time will tell.


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No you dont get what im saying. But im done trying to explain...lol

I havent looked at it closely, maybe doo made shitty i don't know. If they made it proper, it will work just fine for many years

 

[snochuk]

I get what you are saying, but there are different forces on a snowmobile drive shaft, vs a trophy trucks front axle drive shaft. When the trophy trucks suspension cycles that spline is designed to move in and out with the suspension travel.
A snowmobile rear suspension and track, is alot like a dirt bikes rear swing arm. As the suspension compresses, the track gets tighter, same as the chain on a dirt bike.
The spline on the doo drive shaft is seeing that cyclical side loading alot in the bumps. Too tight of a track will make that worse. The only thing holding that coupling and bearing in the chain case true, is the bearing fit, and a circlip.

It does work yep, excellent idea for guys who change tracks alot racing, is the two piece shaft a problem? Remains to be seen IMO, but what I did notice when on the trail was a new noise in the drivetrain, a growling like something was rubbing on the tunnel but nothing was, no ice build up.
I have not heard that noise yet with the one piece shaft. According to my dealer, lots of guys last year complained about that exact noise. Time will tell.


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Wow Matt, that's generally what I said, and you know what somebody thinks I got for brains.
Hope you and your family have a great Christmas bud!!!
Will let ya know when we start riding.

 

[Dazzler]

When you hit a 3ft mogul at 100 mph in a 7000lbs trophy truck do you think it would put some kind of load on the drive shaft at all other than just twisting? The drive shaft cycles up and down with the axle and susupesion. You dont think that would put any kind of load on the splines of the drive shaft other than just twisting? Still talking auto drive shafts here. But no they dont have a track wrapped around them


High angle drive shaft:

View attachment 277132

its all been done before, there is 0 reason a 2 piece shaft with splines won't work on a skidoo.
other than being build too light.




Peace,

Nope.. but ok.

 

[lilduke]

Wow Matt, that's generally what I said, and you know what somebody thinks I got for brains.
Hope you and your family have a great Christmas bud!!!
Will let ya know when we start riding.

Hurt feelings report needed asap

 

[Dazzler]

I get what you are saying, but there are different forces on a snowmobile drive shaft, vs a trophy trucks front axle drive shaft. When the trophy trucks suspension cycles that spline is designed to move in and out with the suspension travel.
A snowmobile rear suspension and track, is alot like a dirt bikes rear swing arm. As the suspension compresses, the track gets tighter, same as the chain on a dirt bike.
The spline on the doo drive shaft is seeing that cyclical side loading alot in the bumps. Too tight of a track will make that worse. The only thing holding that coupling and bearing in the chain case true, is the bearing fit, and a circlip.

It does work yep, excellent idea for guys who change tracks alot racing, is the two piece shaft a problem? Remains to be seen IMO, but what I did notice when on the trail was a new noise in the drivetrain, a growling like something was rubbing on the tunnel but nothing was, no ice build up.
I have not heard that noise yet with the one piece shaft. According to my dealer, lots of guys last year complained about that exact noise. Time will tell.


Sent from my iPad using Tapatalk

Thank you Caper 11. Well explained.

 

[cdnredneck_t3]

Well actually the truck driveshaft slides in/out on splines so only end loaded and typically also carried by a steady bearing, not at all the same.
The sled has an uplift side load on the bottom spline, released and reloaded every time throttle applied and chopped.
Not at all the same dynamics on the spline for wear or magnifying play over time.
But I get how looking through a glass of doolaid makes things look a little murky and misrepresented........

From a Millwrights perspective you are 100% correct. A driveshaft application will not have nearly the radial load as a chain drive. Most of the force on a driveline is torsional. The driveline does move with the axle but the radial force would minimal. I would think there is more axial load as the splines are under torsional force as they are trying to slide as the slip joint when the coupling length is changing as the axle moves.

My take on the Doo two piece driveshaft is it is exactly what happens to a gear or flexible grid coupling with substantial misalignment. The axial length of the spline is not long enough to prevent the drive gear from cocking on the driveshaft. This leads to high 2x rpm vibration. For every shaft revolution the drive gear is moving outboard on the top and inboard on the bottom at the same time doubling the axial movement. This friction overcomes the lubricant and starts to create filings and eats the splines until they give out. If the sprocket binds or seizes onto the shaft it will now force the tension into the chain as shock loading causing extra strain and chain breakage as the chain goes from over tight to slack every revolution, it will also start working at the driveshaft and the wobble could separate the two driveshaft pieces.

 

[lilduke]

Ya a 35lbs rear drive shaft, with a slip yoke in the middle, doing this ^ would definitely would have minimal radial forces acting on the splines.

Uh huh. Thanks for explaining that...

 

[cdnredneck_t3]

Ya a 35lbs rear drive shaft, with a slip yoke in the middle, doing this ^ would definitely would have minimal radial forces acting on the splines.

Uh huh. Thanks for explaining that...

Yep. That's the point of two universal joints and a splined slip joint. It reduces radial and axial load. The problem with the Doo gear and driveshaft is that the radial load is causing misalignment and 2x rpm movement where there is not supposed to be any. A drive shaft has 8 sets of needle bearings designed to allow movement because there is misalignment. Misalignment kills rotating machinery very quickly.

 

[lilduke]

Yep. That's the point of two universal joints and a splined slip joint. It reduces radial and axial load. The problem with the Doo gear and driveshaft is that the radial load is causing misalignment and 2x rpm movement where there is not supposed to be any. Misalignment kills rotating machinery very quickly.

The U joint, reduce it. They don't eliminate it. You still have a heavy shaft slaming up and down at high speed. Watch the vid...

If you didn't have the U-joints you couldnt have moving suspension... Thats why they are there.


On the sled, ya MAYBE the stub shaft is too short. Time will tell

 

[cdnredneck_t3]

The U joint, reduce it. They don't eliminate it. You still have a heavy shaft slaming up and down at high speed. Watch the vid...

If you didn't have the U-joints you couldnt have moving suspension... Thats why they are there.


On the sled, ya MAYBE the stub shaft is too short. Time will tell

Exactly, there are no u-joints or other mechanism to stop the gear from moving on the driveshaft or allow the gear to move without destroying itself. The TKI fix stops the gear movement.

 

[lilduke]

Exactly, there are no u-joints or other mechanism to stop the gear from moving on the driveshaft or allow the gear to move without destroying itself. The TKI fix stops the gear movement.

A U-joint allows a drive shaft to move up and down, (or side to side) without binding. A sled drive shaft is fixed.....


If the spline shaft is long enough, and the tolerances are tight enough and its built strong enough than there is 0 problems...


Put that thing on if it makes you feel better though.



Merry Christmas.

 

[cdnredneck_t3]

A U-joint allows a drive shaft to move up and down, (or side to side) without binding. A sled drive shaft is fixed.....


If the spline shaft is long enough, and the tolerances are tight enough and its built strong enough than there is 0 problems...


Put that thing on if it makes you feel better though.



Merry Christmas.

I don't have a Doo so I don't really care what you Doo. I have seen this exact thing in industry many times and it is doing exactly what a misaligned gear coupling does, except much faster because a gear coupling is filled with grease and are way bigger in a 150hp industrial application. Fix the misalignment and stop the movement the problem will go a way.

 

[lilduke]

I don't have a Doo so I don't really care what you Doo. I have seen this exact thing in industry many times and it is doing exactly what a misaligned gear coupling does, except much faster because a gear coupling is filled with grease and are way bigger in a 150hp industrial application. Fix the misalignment and stop the movement the problem will go a way.

Ok so we both don't care about what the other does. Perfect.

 

[bobsledder]

well this was an entertaining read. I will just leave the driveshaft as is and continue to ride it. It blows will get if fixed but dought it will break.

Out here we just ride em. no time to re engineer them or get together in someones garage to weigh them

 

[snochuk]

From a Millwrights perspective you are 100% correct. A driveshaft application will not have nearly the radial load as a chain drive. Most of the force on a driveline is torsional. The driveline does move with the axle but the radial force would minimal. I would think there is more axial load as the splines are under torsional force as they are trying to slide as the slip joint when the coupling length is changing as the axle moves.

My take on the Doo two piece driveshaft is it is exactly what happens to a gear or flexible grid coupling with substantial misalignment. The axial length of the spline is not long enough to prevent the drive gear from cocking on the driveshaft. This leads to high 2x rpm vibration. For every shaft revolution the drive gear is moving outboard on the top and inboard on the bottom at the same time doubling the axial movement. This friction overcomes the lubricant and starts to create filings and eats the splines until they give out. If the sprocket binds or seizes onto the shaft it will now force the tension into the chain as shock loading causing extra strain and chain breakage as the chain goes from over tight to slack every revolution, it will also start working at the driveshaft and the wobble could separate the two driveshaft pieces.

Maxwell ain't gonna like that one.....
The dukester even less......

When you're dead you don't know it.
Everybody else knows it, but you don't.
Its like that when you're.......
Oh never mind.......

 

[lilduke]

Must be that majic potion from phzers im thinkin

 

[maxwell]

Maxwell ain't gonna like that one.....
The dukester even less......

When you're dead you don't know it.
Everybody else knows it, but you don't.
Its like that when you're.......
Oh never mind.......

haha i didn't witness any driveshaft failures first hand and my sled whaled hard so i wasn't too concerned. i just put oil and gas and go

see how the 24 holds up! i am fatter, might break a shaft this year