Lower Quick Drive Sprocket

[audaveh]

So last week the bolt head failed on the lower sprocket of my Quick Drive.

I replaced the bolt with the upgraded bolt from Polaris, put on a new belt and torqued the upper and lower sprocket bolts to 45 ft lbs.

Today the splines stripped out on the lower sprocket!

Has anybody else had this problem?

2014 Pro 800 155" track

 

[WINJE]

Can you put up some detailed photos? The sprocket splines pilled off?

 

[audaveh]

Photo attached.

 

[ak]

That's a bad casting.

 

[kgra]

Pic isn't quite clear enough to be certain but it looks like the splines peeled out only half way through the hole which would indicate the sprocket wasn't on all the way. Was the bolt loose or broken again? Did you use lock tite?

 

[LoudHandle]

The Hub is not a Casting!

The way they make these Stock QD sprockets is the machined steel splined hub is put in the mold and the rest of the sprocket is cast around the steel hub.

The only way to cause that much wear (to fail / strip) is for the sprocket to be wobbling on the shaft (loose Bolt) until there was nothing left to hold it there.

I hate to say it, but "owner neglect".

Some things need to have the hairy eyeball given to them once in a while, not just gas, oil and go.

Surprising that you did not have any problems sooner than the broken bolt (At least not that you have disclosed).

 

[audaveh]

Just a sliver of splines left on the bolt end. Yes, new factory bolt with pre-installed lock-tite.

 

[Cns81]

C3 lower pully splines stripped

Has any one seen this my 13 has done it twice in 200 miles and bolt was not loose the first time i lock tighted it with an new tension washer i havent tore it a part yet to see why the second time it was on the trail on the way down thank god

 

[summ8rmk]

My friends pro just had this happen.
Aftermarket pulley and bolt was tight. His pulley looked like the pic, splines remained at the outside of pulley.
His let go in a climb, luckily he was able to turn it on its side as soon as it went backward.

snowmow

 

[LoudHandle]

Loose Spline and other tolerance issues from varoius Polaris Vendors

The Polaris vendor that supplies the splined sprocket hubs are usually on the loose side (they very greatly in fit from a machinists perspective). The bolt can not hold the sprocket from turning relative to the shaft (everytime you change throttle position / brake the sprocket hub is walking forward and back on the shaft splines). In time it wears the flat sides of the sprocket hub out as well and the bolt is now loose again, which exacerbates the spline wear, as it is no longer has play in one dimension but instead all three dimensions.

The only true fix is accurate aftermarket gears or hand pick thru stock sprockets until you find a tight one. Then make sure that the shaft is below flush with the sprocket hub face. Use the SkiDoo washers as they are twice as thick and will not flex and bottom on the shaft face. Which will retain the side force pre-load needed to keep everything linear.

Regardless if you are having repeat issues you need to look at everything and figure out why. My bet is the parts have worn enough that your pre-load is gone. No amount of torque will fix that.

 

[Teth-Air]

The Polaris vendor that supplies the splined sprocket hubs are usually on the loose side (they very greatly in fit from a machinists perspective). The bolt can not hold the sprocket from turning relative to the shaft (everytime you change throttle position / brake the sprocket hub is walking forward and back on the shaft splines). In time it wears the flat sides of the sprocket hub out as well and the bolt is now loose again, which exacerbates the spline wear, as it is no longer has play in one dimension but instead all three dimensions.

The only true fix is accurate aftermarket gears or hand pick thru stock sprockets until you find a tight one. Then make sure that the shaft is below flush with the sprocket hub face. Use the SkiDoo washers as they are twice as thick and will not flex and bottom on the shaft face. Which will retain the side force pre-load needed to keep everything linear.

Regardless if you are having repeat issues you need to look at everything and figure out why. My bet is the parts have worn enough that your pre-load is gone. No amount of torque will fix that.

You are correct except it is questionable if it is the driveshaft splines or the gear spines that are the problem. I say this because every time we find a Polaris with a loose fit, the TKI gear also feels loose on that sled. This does not happen on all sleds but we have seen this with all years from 14-17.

Use a 10.9 aftermarket bolt and Loctite 660 on the shaft once you find a good gear.

 

[LoudHandle]

You are correct except it is questionable if it is the driveshaft splines or the gear spines that are the problem. I say this because every time we find a Polaris with a loose fit, the TKI gear also feels loose on that sled. This does not happen on all sleds but we have seen this with all years from 14-17.



Use a 10.9 aftermarket bolt and Loctite 660 on the shaft once you find a good gear.

All I deal with is new take offs, So I stand by my comment. I believe if they (the Owner) have (has) run the loose Stock QD Sprocket on the shaft for any length of time it degrades the fit of the shaft splines accordingly. Hence Your preferred aftermarket vendor's sprockets not fitting as well as we would like them to.