Yukon blog
Breaking In Your Ring And Pinion
Gear break-in consists of controlled heat cycling of the gear set in a way that properly seasons or hardens the gear’s contact surfaces. It is a series of test drives. These critical first few miles of drive time can be the difference between a gear-melting headache and years of carefree driving. Failure to properly break-in your gear set can result in damaged, failing gears, and a complete re-do. Once the wrenches have been laid down and the gears have been properly installed with pinion depth, backlash, and preload correctly set there’s still more to do. The break-in process is really important if you want to have your gears last a long time and perform the way you want them to. The First Drive In the first couple of miles you will want these to be in-town speeds, 15 to 20 mph. Drive for 20 minutes or so, let the diff cool off for about a half an hour, and then repeat the process. Next time you drive your vehicle you’ll want to do some freeway runs. Drive about 15 miles, then pull over and let the drivetrain cool down for about 20 minutes and do this for about 45 miles or so. It may seem like a headache, but it is worth it to ensure the gears are broken in properly instead of burning them up and creating a bunch of metal sledge in your differential. Proper Oiling The next important component is to ensure you have proper lubricants. For the first 500 miles run 80W-90 conventional oil, drain it, and then refill the diff. RANDYS recommends a non-synthetic oil if your set-up features a Dura Grip clutch-type limited slip differential. If you’re running a helical LSD or a locker, synthetics are great for those applications. Break-In For Rigs That Tow Towing with your vehicle or using it for extreme off roading adds additional pressure to the pinion and can slightly change its position on the ring gear teeth. This means you are essentially hardening a new spot on the gear. Therefore, we strongly encourage drivers to follow the same break-in procedure while either towing, hauling, or driving off road. Even if you’ve already broken in the gear set with no addition load follow the same speeds and distances of your previous break-in drives. Start with in-town speeds of 15 to 20 mph, cool down, and repeat. Then hit the freeway and drive 15 miles at 45 to 50 mph, cool down, and repeat for 45 miles. Long distance hauling is the killer for any ring gear set as you are constantly generating heat without cooling which will break down the gear oil and burn up the gear surface. This is why we recommend a gear oil change after the first 500 miles. If you want to protect your investment and get the best performance out of your gears, then proper break-in is critical. Following the guidelines outlined here will ensure you get the expected results.
Lock & Load With Yukon Traction Devices – Dura Grip LSD, Zip Locker, Grizzly Locker
Yukon has tried-and-proven traction devices designed to handle all types of tough terrain. Choose from the Yukon Dura Grip limited slip differential, Yukon Zip Locker, or the Yukon Grizzly Locker. In order to make a more informed choice, here are some factors to consider when looking at traction adders. Differences Between LSDs & Lockers In their static state, limited slip differentials are pre-loaded and provide traction to both wheels. When the LSD is further loaded under acceleration, in a fast corner, or when wheel slippage occurs off-road, the clutch packs limit wheelspin across the drive axle by permitting the axle shafts to spin at different speeds while continuously trying to balance the application of torque between the two axles. This results in transferring more power to the wheel with the best traction. Lockers produce 100% lock-up where all the power is directed to both tires when the unit is engaged. Lockers are tougher than limited slips. Limited slip differentials do not generate 100% lock-up and do not require activation from the driver. Their engagement is mechanical, reacting to driving conditions such as load and wheel slippage. Yukon Dura Grip LSD The Yukon Dura Grip is a great choice for transforming an open differential into a highly capable unit that can provide two-wheel grip when needed. Engineered for long life and completely rebuildable, Dura Grips feature a high-strength nodular case, forged 4320 chromoly spider gears, and composite clutches. In clutch-type LSDs like the Dura Grip, the spring array applies pressure to the side gears, which puts pressure on the clutch packs in the outer part of the carrier. Both axles receive equal pressure and traction. When a tire starts slipping, the clutch packs engage with different resistance to maintain synchronization between the tires, transferring more torque to the tire with the best grip. Rebuilding a Dura Grip involves replacing the clutches in the unit. Clutches can be replaced to restore original performance, or non-stock clutches and springs can be used to fine-tune performance for specific driving or racing styles. Shop Yukon Dura Grip LSD Differences Between Yukon Zip & Grizzly Lockers The primary difference between these two lockers is actuation. The Yukon Zip Locker is air actuated, while the Grizzly is a mechanical locker. An advantage of an air-actuated locker like the Zip Locker is the ability to choose when to engage the unit, along with superior on-road performance. A drawback is the need to purchase and plumb an air system to operate the locker. Mechanical lockers like the Grizzly are always active, providing 100% lock-up at all times, including on the road. On-throttle conditions induce locking, while off-throttle situations partially unlock the unit. During turns, the unit may produce a loud clicking sound as the gears ratchet, which may be undesirable for vehicles that spend significant time on the street. The bottom line is that Yukon is a one-stop traction destination, offering products for all levels of performance, from daily drivers and weekend warriors to dedicated rock crawlers and drag racers that demand maximum traction. Shop Yukon Zip Lockers Shop Yukon Grizzly Lockers
Tales From The Tech Line: Re-Gearing A Jeep JLU Wrangler With 35-Inch Tires
Q- Hello Yukon Team, I have a 2021 Jeep Wrangler JLU Sport S. I was able to retrieve my build sheet based on VIN and I have a M186 front axle and M220 rear axle with stock 3.45 gearing. I have a limited slip differential in the rear and an open differential in the front. I recently completed a 3.5-inch suspension lift and added 35 x 12.5R17 tires. As you probably are aware, this has made the Jeep pretty gutless. I should also mention I have a six-speed manual with the 3.6-liter Pentastar V6 engine. My goal is to use the Jeep as a daily driver with occasional overland trips and off-roading throughout the year. I am under the impression that 4.56 gears are a good fit for my application. My questions for your team are: Is a 4.56 gear set right for my application, keeping in mind it’s a daily driver with overlanding that consists of long-distance highway driving to the trail and mild to moderate off-roading? Do I require new differential carriers to go with the new ring and pinion sets when increasing gearing from 3.45 to 4.56, or will my existing differential carriers work? Do you make a locker that fits a front M186 axle? Do you make a 4.56 ring and pinion gear set for both the M186 and M220? I appreciate your time and guidance on these newbie questions. I look forward to your response and any further knowledge or guidance you can share with me. Regards, Brandon Williams A- Hey Brandon, You are correct, the 3.6-liter “minivan” motor is no torque monster by any stretch of the imagination, but it does run fairly well when allowed to rev a little. Engine speed in this application is actually advantageous, as it allows the motor to operate in a rev range where it produces more torque, volumetric efficiency improves, and brake-specific fuel consumption comes down. Jeeps with automatic transmissions will downshift easily to stay in this range, but manual transmission versions must be driven more like a four-cylinder rather than lugged like a V8 or diesel. That being said, everything Jeep does revolves around meeting corporate average fuel economy (CAFE) standards in a test environment, not the real world. As a result, performance is optimized for fuel efficiency rather than real-world drivability. Using stock RPM or road characteristics as a baseline often leads to disappointment. My recommendation for a manual transmission Jeep JL on 35-inch tires is 4.88 gears. As shown in the chart below, this results in just over 2,000 RPM at 60 mph, only about 350 RPM higher than stock cruising speed. This places the engine in a range where it can better compensate for added wind load, rotating mass, and rolling resistance from your modifications. Many people worry about highway drivability or excessive cruising RPM on long trips. In the next chart, you can see RPM versus speed in each gear. Even at sustained speeds of 85–90 mph, engine speed remains under 3,000 RPM. For climbs such as the Continental Divide or other long ascents, fourth gear remains usable at highway speeds when additional power is needed. Regarding overlanding, if you plan to build the Jeep very heavy or tow a tent trailer, going deeper than 4.88 gears may make sense. Gear ratios like 5.38 are not uncommon for towing on 35-inch tires. Even then, cruising RPM remains reasonable at just over 2,200 RPM. An added benefit is that the Jeep will feel noticeably more responsive. Hopefully this information helps clarify some of the misleading half-truths found online. As far as parts go, we offer complete packages for what you need. New carriers are not required for the gear swap, but they will be needed if you decide to add traction upgrades. For a daily driver and moderate off-road use, we generally recommend a helical limited slip in the front. These operate seamlessly and create no on-road drivability issues. In snowy or icy conditions when using 4-High, lockers can actually create more problems than they solve. The two links below include everything you need to complete the job, aside from fluids, tools, and beverages. Complete Yukon 4.88 Ring and Pinion Gear Set & Installation Kit USA Standard Gear Spartan Gear-Driven LSD for Dana 30 Feel free to reach back out if you have any further questions. Gus Pyeatt, Tech Support Specialist
Yukon Hardcore Diff Covers: A Fortress of Tough Nodular Iron
Upgrade Your Diff Cover and Avoid Costly Repairs Yukon Hardcore Diff Covers are designed to protect lockers, gears, and axles from the abuse that makes wheeling an adventure. Yukon covers are constructed from thick-walled, high-strength ductile nodular iron to endure the most severe impacts Mother Nature can dish out. They also increase the structural rigidity of the differential, reducing deflection under high-torque situations that can put severe loads on internal parts. It’s no secret that the underside of your rig can take a beating. Whether you’re deep into a high-angle rock crawl, pulling rope and winching, or running hard on the track, aftermarket bumpers, skid plates, and rocker guards all play a critical role in keeping vital underbelly components safe. But what about your diff? It’s the lowest hanging fruit and very susceptible to damage. Crack or break a diff cover and you’re done for the day. Stock differential covers can be overwhelmed when the going gets tough. Stamped-steel construction makes them prone to failure. Dent damage can cause interference with ring and pinion gears and spider gears, which will bring your day to a grinding halt. Another failure is cracking. Cracks let gear oil out and allow water, mud, and debris in. Both scenarios will end your fun and lead to large repair bills. Heat dissipation is also a function of a cover’s structural design. Yukon engineers contour the inner surfaces of the cover to circulate oil more rapidly throughout the housing, allowing for faster cooling. This reduces friction, heat, and wear. Each Yukon Hardcore Diff Cover includes alloy steel fasteners that reliably seal the housing for leak-free performance. High-quality magnetic drain plugs allow for quick maintenance, and select models feature twin fill plugs to maximize oil capacity. Thick-walled nodular iron cover built to withstand extreme impacts Streamlined interior contours direct oil flow to the pinion Includes high-strength alloy steel fasteners Heavy-duty protection for added peace of mind Style has its place, and these covers look great. They feature a durable black powder coat finish contrasted by a stainless-steel Yukon accent plate and exposed cover bolts. Yukon Hardcore Diff Covers are available for many popular differentials. Review the application chart below or shop the full lineup to increase the durability and protection of your drivetrain. Call Now 866-631-0196 Shop All Hardcore Diff Covers Part Number and Differential Application YHCC-D30 – Dana 30, 10 Bolt YHCC-D30JL – Jeep JL Dana 30, 12 Bolt YHCC-D35JL – Jeep JL Dana 35, 12 Bolt YHCC-D44 – Dana 44 YHCC-D44JL-Front – Jeep JL 44 Front (M220) YHCC-D44JL-Rear – Jeep JL 44 Rear (M210) YHCC-D60 – Dana 50, 60, and 70 YHCC-F8.8 – Ford 8.8 YHCC-GM14T-M – GM 14 Bolt Truck (M8 Bolts) YHCC-GM14T-S – GM 14 Bolt Truck (3/8 inch Bolts) YHCC-GM8.5-M – GM 8.5 Metric YHCC-GM8.5-S – GM 8.5 Standard YHCC-M35 – Model 35 Rear
Yukon 2021 Holiday Gift Guide
Santa’s gearing up for his big trip south. If you have car enthusiasts on your list and are having a hard time checking off some boxes, the Yukon Holiday Gift Guide is here to help. From fashionable apparel for their stockings to hardcore driveline parts that will look great under the tree, this guide has something to make the season brighter. Can’t decide? Test drive one of our nifty gift certificates and let them choose.