The Yamaha Grizzly 660, a workhorse of the ATV world, is renowned for its power and durability. However, even the toughest machines have their weak points, and the axles on the Grizzly 660 can sometimes present challenges. Understanding the potential problems, their causes, and how to address them is crucial for keeping your Grizzly running smoothly on the trails and minimizing downtime.

Common Culprits: What's Going Wrong With Your Grizzly 660 Axles?

Several factors can contribute to axle problems on your Yamaha Grizzly 660. Let's break down the most common issues and why they occur:

  • Aggressive Riding Styles: This is arguably the biggest contributor. Pushing your Grizzly to its limits with frequent hard acceleration, rock crawling, and jumping puts immense stress on the axles. The sudden jolts and increased torque can quickly lead to bending, twisting, or even snapping.
  • Overloading the ATV: The Grizzly 660 has a specified load capacity. Exceeding this weight limit, especially when combined with rough terrain, puts undue pressure on the axles, accelerating wear and tear.
  • Lack of Proper Maintenance: Neglecting regular maintenance, particularly greasing the axle components, can lead to friction and premature failure. Dry joints are prone to seizing and increased stress concentration.
  • Water and Mud Ingress: Riding through deep water and mud can contaminate the CV joints (Constant Velocity joints) with abrasive particles. This contamination degrades the grease and accelerates wear, leading to joint failure and ultimately, axle problems.
  • Worn CV Joints: The CV joints are critical for allowing the axles to articulate smoothly as the suspension moves. Over time, these joints can wear out, developing play and causing vibrations. If left unchecked, worn CV joints will eventually lead to axle failure.
  • Damaged or Torn CV Boots: The CV boots protect the CV joints from dirt, water, and debris. If these boots are torn or damaged, contaminants can enter the joint, leading to rapid wear and tear. Replacing torn boots promptly is crucial for preventing more significant and costly repairs.
  • Using Incorrect or Low-Quality Replacement Parts: When replacing axles or CV joints, using aftermarket parts that don't meet OEM specifications can lead to problems. Inferior materials and poor construction can result in premature failure.
  • Impact Damage: Hitting rocks, stumps, or other obstacles can directly damage the axles, causing bends, cracks, or even complete breakage. This is especially common in rocky or wooded terrain.

Spotting the Signs: How to Diagnose Axle Trouble

Recognizing the symptoms of axle problems early can save you time, money, and potential headaches down the road. Here are some telltale signs to watch out for:

  • Clicking or Popping Noises: This is often the first sign of a worn or damaged CV joint. The noise will typically be more pronounced when turning, especially at low speeds.
  • Vibrations: Excessive vibrations, particularly at higher speeds, can indicate a bent axle or a failing CV joint. The vibrations may be felt through the handlebars or seat.
  • Grease Leaks: Leaking grease around the CV joints or axles indicates a damaged CV boot. Ignoring this can quickly lead to CV joint failure.
  • Excessive Play in the Axle: Grab the axle and try to move it up and down or side to side. Excessive play indicates worn bearings or CV joints.
  • Difficulty Steering: A damaged or binding axle can make steering difficult, especially at low speeds.
  • Visible Damage: Inspect the axles for any visible bends, cracks, or other damage. Also, check the CV boots for tears or punctures.

Prevention is Key: Keeping Your Grizzly 660 Axles in Top Shape

While axle problems can be frustrating, many can be prevented with proper care and maintenance. Here are some tips to help keep your Grizzly 660 axles in good condition:

  • Ride Responsibly: Avoid excessively aggressive riding styles that put undue stress on the axles.
  • Maintain Proper Load Limits: Don't overload your ATV. Adhere to the manufacturer's specified load capacity.
  • Regularly Grease Axle Components: Grease the CV joints and other axle components regularly, following the manufacturer's recommendations. Use a high-quality grease specifically designed for CV joints.
  • Inspect CV Boots Regularly: Check the CV boots for tears or damage frequently. Replace damaged boots promptly to prevent contamination.
  • Avoid Deep Water and Mud: Minimize riding through deep water and mud. If you must cross these obstacles, be sure to clean and grease the axle components afterward.
  • Use Quality Replacement Parts: When replacing axles or CV joints, use high-quality aftermarket parts or OEM replacements.
  • Consider Upgraded Axles: If you frequently ride aggressively or carry heavy loads, consider upgrading to heavy-duty axles. These axles are designed to withstand more stress and are less prone to failure.
  • Proper Storage: When storing your Grizzly for extended periods, elevate it to take the weight off the tires and axles. This can help prevent flat spots and reduce stress on the axle components.

When Replacement is Necessary: Choosing the Right Axles

If your Grizzly 660 axles are damaged beyond repair, replacement is necessary. Here's what to consider when choosing replacement axles:

  • OEM vs. Aftermarket: OEM (Original Equipment Manufacturer) axles are made to the exact specifications of the original axles and are typically the most reliable option. However, they can also be the most expensive. Aftermarket axles can be a more affordable option, but it's essential to choose a reputable brand known for quality and durability.
  • Axle Material: Axles are typically made from steel alloys. Look for axles made from high-strength alloys like 4340 chromoly steel, which offer excellent strength and durability.
  • CV Joint Design: The design of the CV joints can also impact axle performance. Look for CV joints with larger bearings and improved sealing to prevent contamination.
  • Heavy-Duty Options: If you frequently ride aggressively or carry heavy loads, consider upgrading to heavy-duty axles. These axles are designed to withstand more stress and are less prone to failure. Many aftermarket companies offer heavy-duty axles with larger diameter shafts and stronger CV joints.
  • Warranty: Choose axles that come with a warranty. This provides peace of mind and protects you against defects in materials or workmanship.
  • Read Reviews: Before purchasing replacement axles, read reviews from other Grizzly 660 owners. This can provide valuable insights into the performance and durability of different axle brands and models.

The DIY Approach: Replacing Your Grizzly 660 Axles

Replacing the axles on your Yamaha Grizzly 660 is a task that many experienced DIY mechanics can tackle. However, it's essential to have the right tools and a good understanding of the procedure. Here's a general overview of the steps involved:

  1. Gather Your Tools and Supplies: You'll need a socket set, wrenches, a hammer, a punch, pliers, grease, penetrating oil, and a torque wrench. You'll also need a new axle and potentially new CV boots and clamps.
  2. Loosen the Lug Nuts: Before lifting the ATV, loosen the lug nuts on the wheel of the axle you're replacing.
  3. Lift the ATV: Use a jack to lift the ATV and secure it with jack stands.
  4. Remove the Wheel: Remove the lug nuts and take off the wheel.
  5. Remove the Brake Caliper: Carefully remove the brake caliper and secure it out of the way. Be careful not to damage the brake lines.
  6. Remove the Hub Nut: Remove the hub nut that secures the axle to the hub. This nut can be very tight, so you may need to use a breaker bar or impact wrench.
  7. Separate the Hub from the Axle: Use a hammer and punch to gently tap the axle out of the hub. You may need to use penetrating oil to loosen any corrosion.
  8. Remove the Axle from the Differential: Depending on the axle design, you may need to remove a retaining clip or use a slide hammer to remove the axle from the differential.
  9. Install the New Axle: Carefully install the new axle into the differential and hub, making sure it's properly seated.
  10. Reassemble: Reassemble the hub nut, brake caliper, and wheel.
  11. Torque to Specification: Torque all nuts and bolts to the manufacturer's specified torque values.
  12. Repeat for Other Side: If replacing both axles, repeat the process on the other side.

Important Considerations:

  • Safety First: Always wear safety glasses and gloves when working on your ATV.
  • Consult a Service Manual: Refer to your Yamaha Grizzly 660 service manual for detailed instructions and torque specifications.
  • If in Doubt, Seek Professional Help: If you're not comfortable performing this repair yourself, take your ATV to a qualified mechanic.

Frequently Asked Questions About Grizzly 660 Axle Problems

  • Why are my Grizzly 660 axles clicking when I turn? This is a common sign of a worn or damaged CV joint. The clicking noise is caused by the worn components within the joint binding and releasing as the axle rotates.

  • How often should I grease my Grizzly 660 axles? You should grease your axles at every service interval, or more frequently if you ride in wet or muddy conditions. Refer to your owner's manual for specific recommendations.

  • Can I replace just the CV joint instead of the entire axle? Yes, you can often replace just the CV joint. However, if the axle itself is damaged, it's best to replace the entire unit.

  • What is the difference between OEM and aftermarket axles? OEM axles are made by the original manufacturer to the exact specifications of the original part. Aftermarket axles are made by third-party companies and can vary in quality and durability.

  • How do I prevent my CV boots from tearing? Regularly inspect your CV boots for damage and replace them promptly if you find any tears or punctures. Also, avoid riding through sharp debris that could damage the boots.

Final Thoughts

Addressing axle problems on your Yamaha Grizzly 660 promptly and effectively is essential for maintaining its performance and ensuring your safety on the trails. By understanding the common causes of axle failure, recognizing the symptoms, and implementing preventative maintenance measures, you can keep your Grizzly running strong for years to come. Consider upgrading to heavy-duty axles for increased durability if you frequently ride aggressively or carry heavy loads.