M6 XL-4 Frequently Asked Questions << M6 XL4 The M6 appears to 'hang out' over the edge of the primary case. Is that normal? In some cases, the M6 actually extends out past the primary case. This is normal. Is there a specifc primary fluid that needs to be used with the M6 and it's components? No. The M6 does not require any special pirmary fluid. The "shoe" material is designed to be used with any "normal" primary fluid. Not only do we follow Harley with their suggested primary fluid, but we also recommend popular after market brands and have had no instances of brittlness or premature wear when other primary fluids are used. "The primary fluid you are currently running will work fine with the M6". Do the SPRINGS ever wear out of get weak? What if I break a spring? Our SPRINGS are custom made for us. You cannot buy them in a hardware store. It is unusual that we ever have to replace springs but they can always be purchased directly from us. How long will the M6 last? One of our first installations (over 13 years ago) now is approaching 600,000 miles on the M6. He has installed 3 primary chains during that time, but figures when you can get over 100,000 miles on a chain you are doing real darn good. AND, he's still on his first SHOE. How long can I expect the SHOE to last? It is not unusual to see well over 100K miles on an M6 shoe. As long as the correct lubricate is used in the primary case and the M6 is checked for wear every 20,000 miles, you should expect to have a long shoe life. Replacement SHOES can always be purchased directly from us. You do NOT need to purchase a 'complete' M6. What if I loose my extra SHIMS? You can always purchase any of the pieces of the M6 directly from us. My bike is making a WHIRLING sound. What is it? The M6 does not have any 'hooks' into your system. We are merely providing a surface for the chain to glide over. In some cases, we have had a 'whirling' sound reported to us. This sound is simply the chain gliding over this shoe. It will generally subside within the first 200-300 miles. Most installations don't hear this at all. If you should, don't be alarmed. It is not causing any pre-mature wear on your chain or our shoe. How often should I check the M6? Check the unit for wear every 20,000 miles...always keep clean oil. How tight should the nut be? Torque the nut to 33 ft. pounds. Add a touch of loctite and you're done. << M6 XL4