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Discussion Starter · #1 ·
Well for the second time in the grizz's life I stripped the threads out of my inner sheave. I know this is a common problem with these, but has any body figures out what causes the problem. I am currently running 2mm shims with greaseless weights on a moded outer sheave. outer nut did not come loose and was torqued and locktighted in place. With my riding group this is about the fifth inner sheave we have replaced. Not a real big deal but still a pain in the you know where because it let go in about 10' of snow and had to get pulled off the mountain.
 

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Just a guess but you may be running to much shim for the 700. I've read about 1.7 being about max. More and there is not enough spline for the plate to sit on properly.
 

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DJ
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:shucks: I assume you mean splines instead of threads of the inner sheave? When running more than 1mm it's a good idea to use a thinner washer at the cam plate, make sure it's centered over the splines so your not torqueing the washer against the splines. If the washer is not centered and gets torqued against the splines instead of the collar (the collar is what holds the inner sheave tight) this will allow play in the splines of the inner sheave stripping them out.
Lots of people running up to 2mm of shim without any problems with the inner sheave. Just take care to center the washer and torque the nut to 92ftlbs.
You can eliminate the problem entirely by getting a Coop45 machined sliding primary sheave. No top end speed loss like you have with shims.
 

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Discussion Starter · #4 ·
Did not read what I was writing when I said threads, sorry about that. Yes, the splines on the inner sheave are the ones that I am stripping out, not the camplate splines. The inner sheave splines are not affected by the shims. The inner sheave rests against the oneway bearing.
 

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DJ
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Did not read what I was writing when I said threads, sorry about that. Yes, the splines on the inner sheave are the ones that I am stripping out, not the camplate splines. The inner sheave splines are not affected by the shims. The inner sheave rests against the oneway bearing.
:pullinhair: The point is that when using shims there is less spline sticking out from the cam plate to "center" the washer over and if the washer is not centered you may be torqueing the nut and washer against the splines/spline taper rather than the collar which is what keeps the inner sheave tight and that is the major cause of spline failure on the inner sheave when using shims.
Stripping the inner sheave splines has not been a common problem when using a thinner washer and care is taken to center the washer when using shims and properly torqueing the primary shaft nut.
 

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Discussion Starter · #6 ·
I get your point. Thank you. I will be more observant when putting the new inner sheave on. I may have missed something having only installed about 25 of these mods. The ones that have had issues are grizzlys that have been heavily modified. I thought maybe that had something to do with it.
 

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DJ
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I am currently running 2mm shims with greaseless weights on a moded outer sheave. outer nut did not come loose and was torqued and locktighted in place. With my riding group this is about the fifth inner sheave we have replaced. Not a real big deal but still a pain in the you know where because it let go in about 10' of snow and had to get pulled off the mountain.
Not sure how you can be running 2mm of shim with a modified sliding primary sheave without the belt dropping "too far into the primary" and riding on the seal collar or bottoming out on the collar the movable sheave slides on?

What type of mods are done to the outer sheave and who did them? The max amount of shim I have heard of anyone running in a 700 Grizz with a Coop45 or JBS sheave is 1mm before the belt rubs a hole in the CVT cover or belt rides too low in the primary. 660s may be able run more shim without rubbing hole n the CVT cover but I would think the belt would be too low in the primary with a machined sheave and 2mm of shim?
 
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