A
AK IQ Pilot
Well-known member
2 of the 6 had blown belts prior to last weekend. On the last belt that blew we immediately checked pulley and rotor temp. Rotor was cool. Top pulley was sizzling.
SOME THOUGHTS ON QuickDrive® BELT ISSUES
- Thread starter mountainhorse
- Start date
2 of the 6 had blown belts prior to last weekend. On the last belt that blew we immediately checked pulley and rotor temp. Rotor was cool. Top pulley was sizzling.
How is the fitment of the belt to top sprocket? From the description it sounds like the belt is not rolling on and off the sprocket like it should but maybe sliding in and out of it? Tooth profile error? So the harder you load the sled, the more sliding friction it generates and the result is the excessive heat load.
I may not be describing it well enough, but the belt tooth is a fixed size and the resulting sprocket tooth is a thinner profile with the smaller diameter (tooth count sprocket) if this is off; too wide then it is pinching the belt tooth or too thin it is slipping / sliding as it transfers the motion. Either one will result in heat generation.
I may not be describing it well enough, but the belt tooth is a fixed size and the resulting sprocket tooth is a thinner profile with the smaller diameter (tooth count sprocket) if this is off; too wide then it is pinching the belt tooth or too thin it is slipping / sliding as it transfers the motion. Either one will result in heat generation.
A
Anthony Oberti
Well-known member
I just want to say this about the belt and what not. How can Polaris say, oh no landing on the throttle and let your sled cool down and these sleds are not designed for big horespower when that is EXACTLY what your poster boy Chris Burandt does EVERY DAY!!!! Chirs has a turbo, a 900 and beats his sld like no other....AND....Polaris uses his as their biggest marketing piece. Yet, riders should not ride like this what-so-ever? Just something to think about.....
...and steel driveshafts. 
A
Anthony Oberti
Well-known member
...and steel driveshafts.
Yep!!
P
phatboyfilms
Well-known member
what would one consider normal or ok runout. i just blew a belt @ 250ish miles & dont want to go through another. thx !
For me one or two thousandths would be my limit just like crankshaft run out. If you have 3-4 and your out of warranty that's your call, new shaft or keep buying belts? If your five or more trash the shaft and move on. Just my opinion though.
P
phatboyfilms
Well-known member
After reading this i payed closer attention to sprockets. My top sprocket was sizzling (can only touch for quick sec) Everytime I cked it. Can't be good on the belt. Any solutions?
How much of this heat is from the bearing inner race spinning on the jackshaft issue?? Or is that only occuring in very isolated case? Seems it wouldn't take much of that to crank quite a bit of heat into the pulley. ??
I thought that the high top sprocket heat has been pinned down to using the same sealed bearing as is on the chaincase models, except the chaincase bearings receive continuous cooling from the gear oil, and the Q-D bearing receive no significant cooling compared to the chaincase versions. Then it is pretty much like a hot knife cutting through a very expensive, one manufacturer supplied, cube of butter. When you could be 30 miles from the trailer.
A
AK IQ Pilot
Well-known member
The sealed bearing on the clutch side of the jackshaft isn't getting hot, not even close to hot. I realize this isn't the same exact bearing but these style of bearings are used in many applications and they don't need any cooling to keep from destroying themselves.
When I was performing all the temperature testing 3 weeks ago I did notice the inner hub of the brake rotor was considerably warmer than the rotor itself. A real accurate temperature of the bearing was impossible because I couldn't get a good shot at it. One thing for sure though, the upper sprocket was by far the hottest component that I could shoot with my gun. In most cases the top sprocket was 30-50 degrees hotter than any other component in the drive train.
I'm finding the same thing on mine. Brake rotor 160 f Belt 95 f lower gear 60 f upper gear 120 f
On my sled the heat is transferring from the brake rotor to the top gear then the to the belt.
It appears that the brake pads are putting some pressure on the rotor at all times. I'm going to try installing some springs between the pads to free them from the rotor when not being used.
A
AK IQ Pilot
Well-known member
I'm sure you have already figured this out but you have to be very careful of the reflection of the shiny upper pulley or you will get much lower temperature readings that reality. I always shaded the pulley from the sunlight when taking the readings and this provided consistent accurate readings.
None of the sleds I have tested showed brake rotor temps above about 90f. Most were 80f or so.
Some sleds must drag the brake.
in reply to original post.
I think the statement that there are rare cases is understated. I have striped two belts in 1200 miles they have replaced shaft and pulleys and done the updates, now they are hoping the problem can be fixed with the new updated belt that Polaris just came out with to fix the problem they done have. My brother in law striped his last week, when he dropped it of at the dealer they said that never happens it was the first they had seen. he asked them if they had forgot the two they had there in one day mine and another that had been dropped of minutes after. I have only rode Polaris for the last 20 years but don't need another Dragon I thought they had go RD straightened out and were doing better testing. I believe it has to do with tension both time I noticed my belt a slight bit loser than my wife's right before they stripped.
I think the statement that there are rare cases is understated. I have striped two belts in 1200 miles they have replaced shaft and pulleys and done the updates, now they are hoping the problem can be fixed with the new updated belt that Polaris just came out with to fix the problem they done have. My brother in law striped his last week, when he dropped it of at the dealer they said that never happens it was the first they had seen. he asked them if they had forgot the two they had there in one day mine and another that had been dropped of minutes after. I have only rode Polaris for the last 20 years but don't need another Dragon I thought they had go RD straightened out and were doing better testing. I believe it has to do with tension both time I noticed my belt a slight bit loser than my wife's right before they stripped.
