I'm new to the Wolverine and SxS's generally, have some mechanical aptitude having worked on various engines and done a number of mods on my trucks, sleds and quads over the years, however clutches are a grey area for me. I see lots of comments about modifying the Wolverine clutch when installing aftermarket tires/wheels. i also see comments about modifying the clutch when predominantly driving in rocky areas with lots of climbing or in areas with deep sand. Some people comment about just generally modifying the sheaves, etc., to improve overall performance.
So, for a guy with a Wolverine R-Spec who does a lot of hunting, mostly in mountainous areas; as well as a lot of touring around in various terrains from desert to swamps; frequently finds himself in mud and/or snow- do I need to modify my clutch or is it fine the way it is? What is involved in modifying a clutch? And, does modifying your clutch with aftermarket parts affect your warranty?
So, sitting here waiting to be educated . . .
First off, I am not sure why, but sheaves and clutching are a largely debated subject on this and other forums alike. It really shouldn't be, as it is not some "black art", it is just physics and mechanical engineering. With that being said, you will encounter people on both sides of the argument, and they will swear on their life that they are correct. It is up to you to decide for yourself after being presented with the facts.
Now, judging by your statement, the simple short answer is NO, you don't NEED to modify your "clutch". The long answer, is YES, you SHOULD modify your clutch...and I will explain why.
The term "clutch" here is being used to describe an entire assembly of parts, including the Primary and Secondary sheave sets, a belt, a one-way bearing, and a wet-clutch shoe assembly with a drum. There are a lot of parts involved here in one assembly.
The stock setup is designed to be SMOOTH, and it is incredibly smooth, above 5-8mph anyway. The stock setup shares similar components and design to the Rhino, which was a lighter machine. However, they changed it up a bit to give the Wolverine a higher top speed. This is part of the reason Flyer suggested the belt being under tremendous load in comparison to the Rhino. He is not incorrect, and the extra load isn't generating excessive heat because it is a constant belt tension design, it doesn't slip like a Polaris for example. This is where the wet clutch comes in.
The stock wet clutch is designed to engage slowly and smoothly for easy starting from a dead stop. If you add heavier than stock tires, and especially taller than stock tires, you will increase the loading of that clutch, and it WILL wear faster. It is not going to implode or anything crazy, but the useful life will be decreased. It will be further decreased if you go with even taller tires, like a 30" for example. In that range, you do run the risk of permanent, irreparable damage to the wet-clutch. The solution to this problem is called "slugging" the wet-clutch. Since the wet-clutch is operated by centrifugal force, we add extra weight to the shoes to make them engage with more force against the drum, and do so sooner than stock. This offers you less slippage and wear on the clutch shoes, and lets you run larger tires without risk of damage. It also allows you to idle along your hunting trails at a lower rpm than stock, and crawl up over obstacle at slower speeds when necessary. This brings us to the Machined Sheave mod.
A machined sheave is just that, it is the outer half of the primary sheave assembly, with some machining done to it to change the drive ratio both on the low end, and the top end. It gives you a lower ratio on the bottom, which allows lower crawling speeds, and a slightly higher ratio on the top end, which allows higher top speeds. The benefit here is not just for the "performance junky", because let's face it, if you were that much a performance junky, you would have purchased a 1000cc machine. The utility benefit is very high here, in the respect that the lower gear ratio will allow less load on the belt, and the wet-clutch when you are towing or hauling say a moose out of the woods for example. This will extend the life of your wet-clutch past what it would be if left stock, it will also increase the pulling capability, due to higher applied torque to the wheels. Essentially, you are getting more power to the ground when starting out from a dead stop. Now, on the performance side, you will absolutely notice a HUGE difference in acceleration over stock, and the backshifting will be faster as well. This refers to mashing the pedal when cruising at 25mph for example, and the CVT assembly "downshifts" and you accelerate. The CVT changes ratio based on engine load and speed, and the machined sheave kit (with heavier spring) will help this function better than stock, especially with larger tires.
So, with this brief synopsis, you should be able to do some more research on your own, watch some videos, etc. To answer the question about what is involved to modify the clutch, a beginner with mechanical skills could do a slug and sheave kit in about 6 hours, and that's including the time to cuss and drink and figure out how to take all the pieces off the machine to even get to the CVT assembly LOL. As for the warranty question, YES, technically Yamaha can refuse to warranty any failure on the machine that it deems was caused by your modification. There is always that risk. However, it all depends on your local dealer, some don't care what is modified, some do.
If it were me in your shoes, based on your riding habits you list, I would want to slug the wet-clutch and add a machined sheave. BUT, that is just my opinion...and we ALL know what they say about opinions....
Good Luck
FTM
