With dealers and riders starting to take delivery of the 858 Catalyst (BTW let’s give a round of applause to Arctic Cat on getting these sleds built and delivered before the snow flies) I’ve received emails and messages asking about the “changed” ADAPT clutch found on the big bore buggy. For starters the praises of the ADAPT clutch are many and deserving, and Kale did a great job highlighting those changes and also providing details on how to upgrade your older sled to the new ADAPT clutch. Now the 858 is coming with more changes to this ultra durable system…here’s an inside look.
With higher horsepower engines becoming the norm across the industry, regardless of brand, clutch failure has and is becoming a highly sensitive and emotional subject for owners. What’s more, with horsepower expected to continue to increase, it has the potential to become an even bigger issue. Knowing this, Arctic Cat decided to “fix it with a hammer”, which meant developing a clutch so robust, with extreme durability cycle performance that it not only fixes any potential problems now, but well into the future. The primary changes to the updated ADAPT drive clutch include a steel spider, updated cover casting, the introduction of dowel pins, and new weights. Let’s take a look at each in detail. While the black color of the spider may be the first thing that alerts you that something is different, there’s a lot more going on with this new steel spider than meets the eye. The forged one-piece design is 10-times more durable and offers up twice the material strength versus the previous version. According to Arctic Cat engineering, it also improves clutch balancing and based on early testing, actually extends engine life by reducing unwanted vibration. Oh. and that shiny black color? That’s not just for looks, its an electrophoretic coating that after being subjected to Arctic’s salt spray test adds an additional 200-plus hours of corrosion and rust prohibiting protection. The new clutch cover incorporates several changes that you won’t see at first glance. A new casting process that starts from the center results in increased strength. The casting itself is also twice as thick around the bolt holes and features a wider engagement area onto the moveable towers. The most notable and possibly the most important change to the drive clutch is the use of matched reamed dowel pins to attach the cover to the towers. I’d put this in the bucket of why didn’t someone think of this before category. The use of dowel pins creates a perfect, matched fit cover to tower and results in 6-times less tower spread. It also reduces vibration, improves durability, and delivers smoother, overall shifting. The new drive clutch was durability tested in 18 hour shifts and measured twice a day for changes in tower tolerances in addition to being rigorously field tested. Here’s a close up example of a matched reamed dowel pin where it fits into the tower casting. You may also notice the tower has more material. This not only accommodates the dowel pin, but also provides more material for bol threads. With this change, the cover bolts are now torqued to 18 ft-lbs versus 13 in the previous design. This CAD rendering best illustrates the reamed matched dowel pin (blue area) with the cover affixed to the towers. Here you can see how the cover is drilled to accommodate the dowel pins. You’ll also notice a shoulder that encapsulates the outside of the tower, adding additional strength and improved tolerances. But wait…there’s more. With changes being made to the spider, towers, and cover, the team was given the opportunity to increase the size and surface of the weights and rollers. The new weights are 40% wider (and can be easily seen in this photo of a previous weights and the new design). The result is significantly reduced wear on both the roller and the weight. Field test results revealed the crew could easily put on more than 3,000 miles on one set of weights and rollers. A view of the larger roller that works in tandem with the new 40% wider T-weights.