Belt trouble...I read the sticky and it was no help

[hayastusa]

I'm on my fourth belt this season. The first was OEM from last year and it delaminated but stayed together while boondocking in deep powder It probably had 1200 miles on it so I thought nothing of it. Figured I'd try an aftermarket belt (gates extreme). After about 300 miles the belt completely let go while boondocking in deep powder (admittedly I was riding hard). The clutches were too hot to touch, and there was nothing left of the belt other than a mile of string wrapped around both primary and secondary and a few small pieces of rubber. Obviously back to OEM, but with about 100 miles I blew by an F7 on the lake and again total and complete belt failure other than the strands of twine wrapped in the secondary, a few pieces of rubber and a detstroyed belt shroud, you'd think I forgot to put one on.

In none of the above, other than the first, was there any warning that the belt might be compromised. No noise, burning, slipping.

Anyone know what's up?

 

[snowbeast]

Are you breaking in you belt with enough easy miles at first,before you try to squeeze it to hard in the steep and deep? I have been washing my brand new yammi 8dn belts,and scrubbing them good before i install them,and i than run them very easy for 20 or so miles,just bringing it up to wfo for a few seconds on groomed trails,also are your clutchs stock,or are you running aftermarket gear? this matters too?

 

[Wartsnuff]

wow,

I have 4800 miles on my orginal belt in my RTX and it still measures within spec...

cheers

 

[maddogjeff]

Could be - motor mounts, jackshaft bearings, jackshaft itself, 3 things that would throw it out of alignment. Lift up rear and engage everything while watching the clutches see if anything bends, vibrates, etc. Or the clutches, it's a tough one. If alignment looks good rebuild the clutches, start with secondary. I blew a belt and the filaments all wrapped around the spindles, real bitch to get them all out, if anything is keeping that secondary from opening all the way no belt will hold up. Good luck.

 

[RTX]

I blew a few belts before checking my clutch alignment.
it was not out a lot but it definately was out.
aprox .062 out on center to center and out about the same on offset.
I re aligned the clutches and have not had a problem.
I plan to check the alignment when i go through the sled this summer. if it is out again i will make a torque arm to hold it in place

 

[snowbeast]

I blew a few belts before checking my clutch alignment.
it was not out a lot but it definately was out.
aprox .062 out on center to center and out about the same on offset.
I re aligned the clutches and have not had a problem.
I plan to check the alignment when i go through the sled this summer. if it is out again i will make a torque arm to hold it in place

Wow .062 thousands is huge,thats not a small amount at all,i am not surprised you had belt wear!!

 

[hayastusa]

Everything is stock. I know nothing about clutch alignment or rebuilding. The action of both appears smooth and normal when I run it on the stand. Guess I'll let the mechanic look at it

 

[Yamapex]

I had same problems with RTX. Bellts would disintegrat with 0 warning, alingent and offset were good but center to center was off, I used the Sled Pro clutch tool it makes the job of alinging very easy. good luck

 

[POB88]

I blew a few belts before checking my clutch alignment.
it was not out a lot but it definately was out.
aprox .062 out on center to center and out about the same on offset.
I re aligned the clutches and have not had a problem.
I plan to check the alignment when i go through the sled this summer. if it is out again i will make a torque arm to hold it in place

My clutch was out of alignment to...about the same.

 

[timc]

Belt issues

I had put my sled away for the Summer a couple weeks ago. I took the belt off and compared it to my new spare to see how much wear it had in 800 miles. It was actually wider by almost 1/8th "!

I checked the part #'s. The original was8DN 17641-01 & The spare is 8DN 17641-00. My dealer says the 01 supercedes to the 00.

I had a chance to go back country riding last Saturday, 4-14-07 in deep wet snow. I put the original belt back on (same direction) and rode 120 miles.

A couple times I got in a position where the sled didn't want to move. Once was crawling over a snowbank. I was the 5th sled in line and it was easy going, just a little tricky to manuver. The sled wouldn't move, just set there and slip the belt. That had happened a couple times in the past trying to load the sled on the trailer too, which I thought was unusual. The belt looked perfect in any event.

To make a long story short, The belt is now the same width as the replacement, The top 1/8 th of the belt came totally delaminated!

The sled has 900 miles on it and is the 1st belt I've lost in 15,000 miles with Ski-Doo's & Arctic Cats.

Tim

 

[Triple X]

Once I took the float out of the secondary(movement from side to side) I haven't had a belt problem since.

 

[maddogjeff]

Once I took the float out of the secondary(movement from side to side) I haven't had a belt problem since.

Don't you need the float to keep things aligned? As the primary closes the belt actually moves towards the engine (only the outside sheave moves), so the secondary has to float with the movement. What am I missing?

Also, how did you stop the float? I'm willing to give it a try.

 

[Triple X]

The offset from the back of the primary to back of the secondary should be 15mm. Lay a straight edge from the back of the primary clutch to the secondary clutch, there should be 15mm between the back of the secondary clutch and the straight edge. When you get the 15mm measurement shim the secondary clutch so there is no movement on the shaft. When the primary closes fully and the secondary opens fully, the belt will be running straight. There's lots of posts on this, do a search, I even think there are some pic's.

 

[POB88]

sheave offset: 13.5-16.5mm (.53-.65in)
secondary sheave freeplay: 1.0-2.0mm (.04-.08in)

 

[Triple X]

floating secondary will result in more belt wear.....MOST ALL racers and tuners believe in a FIXED secondary....which is obviously fixed in the exact position it should be....(15mm)....

I removed the float from my secondary right away....i did a thread on this last season showing how....ask ALLEN ULMER...he will tell you same thing.

Dan

"This thread was from NOS DAN" (page #30 back post)
_________________