q From the moment you roll a quad out of the dealer’s showroom, your wheel bearings start to wear out. Jumping and turning in mud, water, sand and heat, it all speeds up the process. Your stock wheel bearings are sealed and should not be repacked, so consider them disposable. At the first sign of a wobble or grinding sensation coming directly from a front or rear bearing, it’s time to order up new ones.
One of the simplest ways to do this is to ask your aftermarket parts dealer about Pivot Works’ (PW) wheel bearing kits. Unlike the OEM dealer who has a specific part number for every single bearing and seal, the PW kits are a complete package with all the bearings, O-rings and seals to get the job done quickly on the front or rear of your ATV.
For our 2009 Yamaha Raptor race machine, the front standard Pivot Works roller bearing kit retails for $30, and the rear kit sells for $60—stock replacement parts sell for at least double that at the Yamaha dealer. PW also sells tapered bearing kits for some models.
SPIN TO WIN
One of our test riders, Bill Markel, rides his Raptor 700 at every local desert race. Not only does he put hundreds of punishing miles on his Yamaha every weekend, he spends a lot of time washing the machine between races. Believe it or not, washing your quad can be the most hazardous activity to your bearing’s face. High-pressure water can easily penetrate seals and bearings, dissipating grease, causing rust and speeding up wear. After a wash and before every ride, you should check that your wheel hubs are tight yet roll freely and have no play in them.
During a recent maintenance session, Bill noticed his rear bearing carrier would not spin as freely as usual. He did what many ATV owners would do, he raced the machine anyways. And about halfway through the event, he noticed some vibration and shaking coming from the rear end. He backed off the gas and took it easy to the finish. The setback didn’t leave him stranded, but it did prevent him from getting another win. After the race, we met up with Bill to change out his stock bearings with a new Pivot Works kit.
REMOVE AND REPLACE
The overdue bearing replacement is pretty straightforward on the Yamaha. Up front with the tires/wheels and brake calipers removed, a single nut and cotter pin allows you to remove each hub to access the seals and bearings. Then, with a dull screwdriver (we wrapped our oldest medium-flat screwdriver with electrical tape), you need to gently pry up the seals rotating your position with every 1/16-inch pry and remove them from the center of the hub. The covered screwdriver keeps you from gouging the aluminum hub’s sealed surface. After the seal has been removed, the bearings need to be tapped out of the hub. You can use the same dull screwdriver. Again, be careful not to scrape the hub with the screwdriver. It was easiest for us to remove the outside bearing first.
With the bearings and seals removed, you want to clean the hub and surface well with contact cleaner and debur any imperfection with fine-grit sandpaper. Apply a thin layer of wheel-bearing grease to the inside of the hub, where the bearings rest, and on the spindle.
To install the bearings and seals, slightly grease the outer edge of them and tap them back into the hub. We use a socket that is just slightly smaller than the circumference of the bearings and seals and precisely tap them in straight with a small hammer. Repeat the steps with the remaining bearings and seals, then replace the hub, torquing the nut to the manufacturer’s specs. Next, replace the cotter key with a new one.
PROTECT YOUR BACKSIDE
On the rear end, start by removing the right-side hub, then loosen the large axle nut next to the swingarm. The next step is to loosen the chain and remove it from the rear sprocket, then retighten the adjuster. With the axle nut removed, you can remove the caliper bracket using a pair of snap-ring pliers. Now, tap or pull the axle out the left side of the swingarm, then loosen the chain adjuster. You can now slide the bearing carrier out of the swingarm.
Like on the front end, pry the seals out to access the bearings. Then, with the dull screwdriver, tap the bearing out of the carrier by sticking the screwdriver through the middle of the carrier to the inside of the bearings on the other side. Again, rotate as you tap; the bearings will slowly come out of the carrier. If the bearings just fall right out, your carrier is worn and should be replaced. Two of the bearings (there are four total) we pulled out were rusted and were hard to turn. Good thing we removed them—a seized bearing is never fun to deal with.
Grease the axle tube, then replace the bearings and seals. Now, reinstall all components in reverse order. After a quick test ride, recheck the axle and hub nuts. It’s a good idea to throw a wrench on the calipers and chain adjuster as well.
While the new Pivot Works wheel bearings didn’t make our three-year-old Raptor new again, on the trails, we could surely feel the difference. We could even feel the difference rolling the quad on the driveway; it felt 50 pounds lighter, rolled smother and gave us a lot more confidence to race in the desert. The PW bearing kit was easy to install, priced very well, and was the perfect maintenance item to keep our old Raptor on the track and trails for many years to come.
Pivot Works has wheel bearing kits for most sport and utility ATVs. They also carry stock shock, swingarm and A-arm bushing kits as well. Contact Pivot Works at (515) 402-8000 or www.pivotworks.com