randys blog
DIAGNOSING NOISE (PART 1)
Many things can go wrong inside a differential. Although the hints are often subtle, most impending failures give fair warning in the form of noise. Read this article in Español Several situations can create ring-and-pinion noise. If the gears have been quiet and begin to howl, they are probably worn or wearing. If the gears howl during deceleration only, it’s possible that the pinion-bearing preload has loosened. Howling under acceleration at all speeds indicates that something in the differential — gears, pinion or carrier bearings — has worn or no longer keeps the gear alignment correct. If the gears howl while accelerating over a certain speed range, but not all speeds, it’s likely that the gears are worn due to lubrication failure or overloading. When a newly installed gear set howls, suspect the design or setup. A common problem is worn carrier bearings, as indicated by a low-pitch rumble above 20 mph. On vehicles with C-clip axles, the noise may vary while negotiating turns. Worn pinion bearings can cause whirring noises at all speeds, under deceleration and/or acceleration. Pinion bearings tend to whir, rather than rumble, because the pinion is turning several times faster (depending on gear ratio) than the carrier. Badly worn bearings can also cause howl if they do not support the gears correctly. Worn wheel bearings can be difficult to determine. A very bad wheel bearing typically makes itself heard with great clarity; it’s the bearing that is going bad, but not destroyed, that is hard to find. Turning back and forth from hard right to hard left can identify the culprit; however, I’ve been fooled by right-front wheel bearings that make noise when turning right (which heavily loads the inside-left-front wheel bearing, but also loads the outside-right-front bearing). One common situation that may not make any noise: The pinion spins, but the tires don’t rotate. Broken spider gears can render the differential immobile, and usually make a loud, crunching sound as they make their final departure. A broken ring gear will allow the differential to propel the vehicle for about eight feet at a time, then bang or grind as the section with broken teeth tries to engage the pinion. Depending on ratio, a broken pinion tooth (or teeth) will clunk about every two or three feet. A broken axle is easily determined. After it breaks, a C-clip design axle can be pulled out of the housing without unbolting anything — or may even find its own way out. On many bolt-in-design axles, the wheel will give the broken axle shaft away by cambering in at an angle. A high spot on a gear tooth may sound similar to a broken gear, but will only make noise while accelerating or decelerating, since the spot appears on just one side of the offending tooth. A high spot on the ring gear will make a heavy clicking sound about every eight feet; a high spot on the pinion makes noise every two or three feet and is much more pronounced due to its higher frequency. Whether large or small, differential noise is telling you something. Listen carefully! If in doubt, pull off the cover or remove the third member for a closer look. Catching a bad part before is ruins others is definitely worth the effort.
Off-Road Ready Gear Sets For The Jeep JL
When the JL platform hit the trails in 2018 it was quickly embraced by Jeep enthusiasts and most of these Jeep fans were soon on the warpath for performance parts. Like every other Jeep platform, opportunities for aftermarket manufacturers to modify, lift, and accessorize were in wide and varied. In fact, parts were in the pipelines before the JLs were dropped off at dealerships. Jeep’s New Differentials Aftermarket drivetrain engineers working on the new Jeep JL platform were met with a number with design challenges when it came to the ring and pinion gears. The JL launched with a new set of differentials including the D44JL Rear (M220), D44JL Front (M210), and D35JL (M200). Factory engineers designed the ring and pinions for higher efficiencies. Whether this had to do with the JL’s front axle disconnect feature for increased fuel mileage or other powertrain revisions, differential upgrading needed extra engineering focus. Superior Engineering From a design perspective, this factory revision denotes a decrease in the hypoid offset compared to previous JK designs, resulting in a smaller pinion head diameter with increased loading on the teeth. Most aftermarket manufacturers recognized the design change... that was the easy part. Only Yukon noticed that the design change required improvements to the metallurgy as well. Stronger alloys, most notably an increase in the nickel content, were required to handle the additional loads. Superior Metallurgy Diagnosing the significant changes in the OE gears for the JL platform, our team of engineers examined countless material and heat treatment options to effectively address the new hypoid offset. Yukon realized the need to manufacture the JL ring and pinion line with a premium higher strength 4320 material to hold up to the abuse and provide even higher strength than the JK. After testing Yukon against other aftermarket brands, it appeared we were the only aftermarket company to move to higher strength material and produce the strongest aftermarket gears associated with the Jeep JL line. *An increase in the Nickel content (Ni) provides higher tensile and yield strength and improved impact properties. **Aftermarket competitors benchmarked for JL gears show use of lower Nickel (Ni) materials. ***Tensile and Yield strengths are approximate Providing top-of-the-line drivetrain products has been the goal of Yukon Gear & Axle from Day One. Yukon quality labs and engineers go the extra mile to provide you with a product that can be trusted no matter how sketchy the terrain gets. Yukon’s selection of products from gears, traction devices, driveshafts, kits, and covers to name a few, are the highest quality in the industry and we continue to exceed industry standards so you can wheel with confidence.
Copy of JL Metallurgy Overview
New Jeep JL platform provides design challenges in the automotive aftermarket The new JL platform from Jeep quickly became one of the significant introductions from carmakers in many years. Like every other Jeep platform, opportunities for aftermarket manufacturers to modify, lift, and design came quickly after the introduction. For aftermarket drivetrain engineers, working on the new Jeep JL platform provided with design challenges when it came to the ring and pinions. The JL launched with a new set of differentials including the D44JL Rear (M220), D44JL Front (M210) & D35JL (M200). Factory Engineers had designed the ring & pinions for higher efficiencies. Whether this had to do with increased mileage requirement or powertrain revisions, differential modifications were required throughout the platform. From a design perspective, this factory revision denotes a decrease in the hypoid offset from previous JK designs resulting in a smaller pinion head diameter with increased loading on the teeth. Stronger alloys, most notably an increase in the nickel content, are required to handle the increased loads. Most aftermarket manufacturers recognized the design change, that was the easy part. Only Yukon recognized that the design change required improvements to the metallurgyas well. Recognizing the significant changes in the OE gears for the JL platform, Yukon Engineers examined countless material and heat treatment options to effectively deal with the new hypoid offset. Yukon realized the need to manufacture the JL ring & pinion line with a premium higher strength 4320 material to hold up to the abuse and provide even higher strength than the JK. A year later, after testing Yukon against other aftermarket brands, it appears that Yukon was the only aftermarket company to move to the higher strength material and produce the strongest aftermarket gears associated with Jeep JL line.