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Copy of 12 Tech Tips For Differential Assembly & Setup
This quick primer of tech tips is designed to be informational for less experienced installers and a refresher course for seasoned differential technicians. The focus is on time-saving tricks and advice when assembling and setting up a differential, concentrating on preparation, assembly, setting pinion depth, backlash, and more. Anatomy Of A Gear Tooth In order to take full advanatge of the tips and information conveyed in this article we need to get our lingo on the same page. The above schematic outlines the surfaces of a typical gear tooth and how they are generally referred to. 1. Take The Right Approach The order in which adjustments are made during differential assembly and setup are: 1. Pinion Depth 2. Pinion Bearing Preload 3. Backlash 4. Carrier Bearing Preload 2. Pattern Adjustment Cause & Effect Use shims to move the ring gear closer to the pinion to decrease backlash. Use shims to move the ring gear farther from the pinion gear to increase backlash. Use shims to move the pinion closer to the ring gear to move the drive the pattern deeper on the tooth (flank contact) and slightly toward the toe. The coast pattern will move deeper on the tooth and slightly toward the heel. Use shims to move the pinion farther away from the ring gear to move the drive pattern toward the top of the tooth (face) and slightly toward the heel. The coast pattern will move toward the top of the tooth and slightly toward the toe. 3. Remember Your Shim Combination When it comes to shim selection use the same shim combinations from the previous assembly as a baseline when reassembling the differential. 4. Seal Surface Preparation It is wise to polish all seal surfaces with fine-grit emery cloth or sandpaper then wipe all surfaces with a clean rag dampened with either fresh oil or solvent to remove any metal particles. 5. The Importance Of Using Assembly Oil When assembling internal components, coat all bearings and seal surfaces with fresh gear oil. Never use bearing grease on pinion or carrier bearings because it will negatively influence assembly measurements. Coat all seals with grease, preferably white lithium grease. Use clean gear oil if white grease is not available. 6. Trial Pinion Assembly Mock install the pinion with its original shims yet without a crush sleeve to establish an approximate pinion depth. When installing the pinion, tighten the nut slowly until it reaches preload specifications. 7. Initial Carrier Assembly Install the assembled gear carrier with its ring gear into the housing. It is easier to remove and replace the carrier during trial assemblies if the carrier bearing preload is fairly snug instead of tight. 8. Initial Backlash Adjusting Tip Backlash refers to the amount the ring gear can rotate forward and backward when the pinion gear cannot move. The initial backlash setting establishes the basis for all future adjustments. To start, fasten a dial indicator to the gear case or axle housing on the same plane as the ring gear so its contact point touches a tooth at the outermost diameter of the ring gear in a 90-degree relationship to the tooth face. The indicator should measure the amount the ring gear moves when rotated. To measure backlash, prevent the pinion gear from rotating and rotate the ring gear back and forth. The amount the ring gear can move (the amount of play) determines the amount of backlash. When changing the backlash bear in mind that the backlash setting changes about 0.007” for each 0.010” that the carrier moves. For example: Move the carrier 0.010” toward the pinion to decrease the backlash by 0.007”. Move the carrier 0.010” away from the pinion to increase the backlash by 0.007”. This gear pattern indicates the pinion is too close to the ring gear centerline. Use shims to position pinion away from centerline. This gear pattern depicts a pinion that is too far way from the ring gear centerline. Use shims to position pinion closer to the centerline. This is the proper or desirable pattern. Note how the pattern is centered on the tooth from face to flank. There should be some clearance between the pattern and the top of the tooth (face) and between the pattern and the bottom of the tooth (flank). Learn more about ring gear patterns in our “How The Create & Read Ring Gear Patterns” article. 9. Make Large Pinion Depth Adjustments First When changing pinion depth, make large changes until the pattern is close to ideal. Consider 0.005” to 0.015” a large change and 0.002” to 0.004” a small change. Intentionally, make adjustments that move the pinion too far at first. If the pinion moves too far and the pattern changes from one extreme to the other, the correct pattern lies somewhere between the two extremes. Once you home in on the correct pinion depth, make smaller changes until the pattern centers between the face and the flank of the ring gear teeth. Once the backlash and pinion depth meet tolerances, remove the carrier and establish the final pinion bearing preload. 10. How To Fine Tune Backlash If the preload is close and the backlash is too loose, tighten the left adjuster a notch or two until the backlash is correct and the preload is sufficient. If the preload is close and the backlash is too tight, tighten the right adjuster until the backlash is correct and the preload is sufficient. Note: ensure that the last adjustment made to the left adjuster tightens it. Doing so will eliminate the possibility of a space between the adjuster and the bearing race. 11. Shimming Outside Shim Design Carriers This design uses shims between the carrier bearing races and the housing. Initially, set the backlash with very little carrier bearing preload. After setting the backlash, add equal amounts of shims to both sides of the carrier to set the carrier bearing preload as tight as possible without damaging the shims (carrier bearings in this axle design hardly ever fail due to excessive carrier bearing preload). If the preload is close and the backlash is loose, add shims to the left side. This increases the carrier bearing preload and tightens the backlash at the same time. If the preload is close and the backlash is too tight, add shims to the right side. This increases both the carrier bearing preload and the backlash at the same time. 12. Shimming Inside Shim Design Carriers This design uses shims between the carrier bearing and the case. Initially set the backlash tight and the preload light, as it will make carrier removal and installation easier. After setting the backlash, add equal amounts of shims to both sides until the correct preload is achieved. If the preload is close and the backlash is loose, add shims to the left side. This increases the carrier bearing preload and tightens the backlash at the same time. If the preload is close and the backlash is too tight, add shims to the right side. This increases the carrier bearing preload and the backlash at the same time. Shop Re-Gear Kits
Yukon Gear & Axle Toyota Re-Gear Kits
Reclaim Performance in Big-Tire Yotas Toyota owners can now take advantage of performance-engineered Yukon Gear & Axle gear sets that have been proven at King of the Hammers, the granite crags of Moab, and in Ultra4 competition across the country. Yukon’s convenient ring and pinion Re-Gear Kits bundle everything you need to upgrade your Toyota’s front and rear differentials in one simple part number to save you time. These kits feature premium Yukon ring and pinion gears, Master Install Kits with high-quality Timken/Koyo bearings, and all the small parts you’ll need to get your vehicle back on the road quickly so you can make the most of your time on the trail. There are two main reasons to re-gear your ride. The first is to recapture the lost performance and fuel efficiency of a daily driven vehicle that has been upgraded with larger wheels and tires. The second is to fine tune the performance characteristics of a vehicle that is a dedicated off-roader where the focus is more on low-end grunt and mild acceleration. Yukon’s Toyota gear program covers 1996-and-up 4Runners, ’95-and-up Tacomas, and 2000-and-up Tundras. This offering encompasses popular Toyota differentials like the 8.75” rear, 8” clamshell front, and 8” rear that is featured on countless V6-powered Toyota 4x4s. Toyota 8” diffs are stout and utilize a third-member, dropout-style design, much like the Ford 9” and Chrysler 8.75” unit. This means the carrier and internals of the diff can be easily removed for ring and pinion upgrades. Gear Ratio Explained If you’re adding big tires, you’re technically already re-gearing because the increase in tire circumference changes the final drive ratio. Remember, if your Toyota is running a 4.10 gear, the pinion gear spins 4.1 times to generate one revolution of the ring gear. Further, upsizing tires likely increases the un-sprung weight, or rotating mass, of your rolling stock. This also increases the vehicle’s overall rolling resistance. That’s a lot to overcome. On the road, your vehicle will take longer to accelerate, turn a lower engine rpm to maintain a highway speed, and get poor gas mileage because of the increase in weight/rolling resistance. Big tires also put a lot of additional stress on the drivetrain, stock braking system, and factory steering components. Re-Gearing Explained A worrisome trend we’ve seen is owners who think that since their rig has a six-, seven-, or eight-speed transmission they don’t have to upgrade their gear set when they jump up in tire size. The culprit is the increased load of larger tires. It can keep you from realizing the full benefit of the tire upgrade because the transmission won't shift into its higher gears. It's not uncommon to see the tranny hanging out in lower than normal gears at light throttle on the freeway. Or to feel it shuttle shifting, trying to find the right gear for the situation. Even if you’re okay with that, the undue stress on the transmission can lead to early failure and a big hit to your wallet. Changing ring and pinion gears is the answer. Understanding Different Ratios Gear talk can be confusing. Wheelers have different was of talking about the same thing… tall gears, high gears, low gears, deep gears… you get the idea. Tall gears produce a lower numeric ratio i.e. 3.08, 3.73 (or lower), while short gears or deep gears refer to higher numeric ratios i.e. 4.88, 5.29 (or higher). Numerically higher gear ratios produce more torque, are quicker off the line, and deliver a lower top speed. Conversely, lower numeric gear ratios produce less torque, are slower at launch, and deliver a higher top speed. The wrong ratio will cause reduced fuel economy because the engine will work too hard to maintain freeway speeds. Too-high of a numeric ratio will lug the engine so it needs more throttle to attain and maintain freeway velocity. On the other hand, a too-low numeric ratio will produce a high-strung engine that spins fast just to run at freeway speeds. It’s a trade-off. How to Select a Ratio That’s Right for You To figure out what your rig is doing and how to pick the right ratio, you need to know your gear ratio and tire height in stock trim. These factors can be used to determine your engine rpm at a given vehicle speed. The homepage has easy-to-use calculators that compute gear ratio and tire height. Then simply take those numbers and feed them into the RPM Calculator. Use your stock set-up as a baseline to determine your vehicle speed/engine speed relationship in stock trim. Then enter your new tire diameter and adjust the gear ratio to best match stock freeway numbers if you’re wanting to replicate stock drivability or adjust for more low-end pull or top-end fuel mileage if you wish to change the driving dynamics of your rig. Going big-tire is not as simple as getting those 40 inchers to fit then hitting the road. There are cascading effects at work. The big tires impact acceleration, freeway cruising, and many aspects of off-road performance. Yukon Re-Gear Kits allow you to restore that all-important drivability in one fell swoop. Shop Toyota Re-Gear Kits Yukon Gear & Axle Toyota Re-Gear Kits Highlights Re-Gear Kits upgrade your Toyota’s front and rear differentials Saves you time by bundling everything you need to do the job right Regain lost vehicle performance from big-tire upgrades Kits include Yukon ring and pinion gear sets and premium Timken/Koyo bearings
Upgrade Your Toyota’s Drivetrain With Top-Quality Yukon Parts
Toyota’s have earned a long-running cult-like reputation for off-road tenacity for absorbing abuse and overcoming obstacles on the trail. We get it. And we’ve developed hundreds of part numbers dedicated to the illustrious sombrero badge. If you own a Toyota and want to run with the bear we have Grizzly Lockers, Spartan Lockers, Dura Grip limited slip units, Master Overhaul Gear Kits, complete ring and pinion sets, and more. Read this article in Espanol Going Big-Tire On Your Toyota? Upgrading to bigger wheels and tires is a rite of passage in many off-road circles. Whether you like the look or plan to step up your wheeling game, it’s wise to recognize your 35-, 37-, or 40-inch tires need to do more than merely fit. Getting the larger rolling stock under your rig is the beginning of the process, not the end. The larger-than-stock circumference of big tires change your truck’s final drive ratio and can negatively alter its performance. This change can impact acceleration, freeway cruising, and many aspects of off-road performance. It can also put undo load and wear on your driveline. Changing the gear ratio in your Toyota’s front and rear diffs can turn back the clock and recapture your vehicle’s driving characteristics. Yukon’s Toyota re-gear offerings cover 1996-and-up 4Runners, ’95-and-up Tacomas, and 2000-and-up Tundras. Yukon’s re-gear ring and pinion gear set kits encompass many popular Toyota differentials like the 8.75” rear, 8” clamshell front, and the venerable 8” rear that is featured on countless V6-powered Toyota 4x4s. Jump-start your re-gear kit product search here by listing your Toyota’s specs in the part finder here. In The Mood For More Traction? We can steer you to three great traction options: the Yukon Dura Grip positraction LSD, the Yukon Grizzly Locker and the Spartan Locker. Where an open diff will freewheel the tire that lacks traction, the Dura Grip limited slip differential uses clutch packs to funnel traction to the tire that has the best grip. In its static state the unit is pre-loaded and provides traction to both wheels. When it’s further loaded… under acceleration, in a fast corner, or when wheel slippage occurs off-road… the clutch packs will apply more torque to the wheel that has the best traction and reduce the transfer of power to the wheel that’s slipping, giving you the balanced traction you need when you need it. All Toyota Dura Grips are heavy duty four-pinion-gear designs built with a high-strength nodular iron case, forged 4320 chromoly spider gears, and top-quality composite clutches. It should be noted that the clutch packs can be rebuilt to bring the unit back to its original performance level or different clutches can be used to fine tune the Dura Grip’s performance to better match your style of driving. Lockers are the big hitter in the off-roader’s arsenal, providing game changing traction on the trail while retaining near-stock drivability on the road. The Yukon Grizzly Locker is a mechanical locker or automatic locker that requires no pneumatic or electronic activation. It replaces the entire carrier assembly and provides incredible clamping force, forged internals, and a forged 8620 low-nickel alloy steel case that is much more robust than the OE carrier it replaces. During on-throttle driving conditions, load is applied to the differential which induces locking, sending 100 percent of the power to both drive tires equally. The Spartan Locker generates reliable, full-lock-up traction at a low cost. The Spartan Locker is not a singular component you swap in but a collection of parts that converts an open differential carrier (and only an open differential carrier) into a mechanical locker. A typical Spartan Locker consist of a pair of drivers, two side couplers, four alignment pins, four pre-load springs, a hardened cross-pin shaft, a roll pin, and installation wires. These lockers feature heat-treated 9310 steel drivers and couplers for enhanced durability. The advantages of utilizing a Spartan Locker are its 100% lock up and its value. They cost less than half the price of an air-operated locker, and remember this is before factoring in the cost of a pneumatic operating system. Further, Spartan Lockers are about a third the price of a large-frame mechanical locker. Going with a Spartan Locker also pays off when it comes to installation. Since it’s less labor intensive than a large-frame locker, installing a Spartan Locker costs less. The savings can be even more substantial if you handle the install yourself. Got A Tired Drivetrain? When it comes to differential maintenance, Yukon Master Overhaul kits deliver all the high-quality small parts you need to do the job right. Each kit consists of carrier bearings and races, pinion bearings and races, a pinion seal, complete shim kit, ring gear bolts, pinion nut, crush sleeve (if applicable), oil baffles and slingers (if applicable), thread locking compound, marking compound with brush, and a gasket. Yukon Master Overhaul kits are the most comprehensive and complete kits on the market because we do all the research to ensure that every kit is specially tailored to the proper Toyota application. Pre-built Toyota Dropouts Make re-gearing your Toyota easy by ordering a complete assembled dropout. Taking this route delivers a pre-built diff with the ratio you want installed while also saving you the hassle of resetting pre-load and backlash if you were to re-build your existing housing. Yukon heavy-duty dropouts feature upgraded materials and an improved design versus OEM to provide heavy-duty strength, ensuring they are ready to stand up to any abuse you can throw their way. You can elect to upgrade your dropout with double or triple drilled pinion flanges, solid pinion spacers and shims in place of crush sleeves (to better maintain gear setup preload), and you can add a locker or positraction limited slip differential to your build. An added benefit of this approach is installation cost. Going with a rebuilt dropout reduces downtime and saves money on the labor. Further, those comfortable with swapping out the housing can handle the install themselves, saving even more money. Check out our Toyota dropouts for Toyota’s with V6 engines (YP DOTV6) and Toyota’s running the 8" diff (YP DOT8). Yukon also offers Toyota-specific spider gears, yokes, knuckle kits, axles, and small parts like, bearings, u-joints, seals, shims, cross pins, washers, and nuts. The bottom-line message here is hardcore Toyota owners who expect their rides to meet the challenge of the trail or Everyday Joes who primarily drive on the street have found their one-stop shopping destination.
Yukon Gear & Axle Dana 30 Performance Options
The Dana 30 differential has been pulling the front of Jeeps around since the CJ-5s of the early 1970s. Available in high- and low-pinion versions as well as standard and reverse rotation versions, the Dana 30 can be found in Wranglers, Cherokees, Grand Cherokees, and Comanche MJs to name a few. They are also in early Ford Broncos and various AMC applications. Too often the capabilities of this mighty-mite diff are overlooked and enthusiasts swap them out. But the D30 has a huge aftermarket behind it and there are plenty of spares waiting for rescue in junkyards across the country… the D30 is begging to be built! Thrive Don’t Just Survive If you’re rolling a Dana 30 why not take advantage of its extensive modification potential? It’s a great landing spot for drop-in lockersockers like our Spartan Locker, large-frame lockers like our Yukon Zip and Grizzly units, and positraction limited slip differentials like our Spartan Helical LSD. Spartan Locker Spartan Locker The Spartan Locker is known as a drop-in or lunchbox locker. This product is not a single unit that is swapped into your pumpkin, it is a collection of components that transform an open differential carrier into a locker. Typically, a Spartan Locker consist of a pair of drivers, two side couplers, four alignment pins, four pre-load springs, a hardened cross-pin shaft, a roll pin, and installation wires. Yukon Grizzly Locker and Yukon Zip Locker Large-frame lockers, like the Yukon Grizzly and Zip, replace the carrier as a single unit and their case is constructed from a muchstronger alloy steel compared to the factory carrier. The main difference between these units is operational… the Zip Locker is an air locker that is operated by a pneumatic system and the Grizzly is a mechanical unit. Yukon Grizzly Locker Mechanical lockers like the Yukon Grizzly Locker, sometimes referred to as automatic lockers, are always engaged. During normal mild-throttle situations where load is applied to the differential, the unit is locked. When the vehicle is turning, the locker produces a clicking sound as the square-cut side gears move over and past one another. This ratcheting sound can be loud and is why mechanical units may not be best suited for vehicles that spend a lot of time on the street… it all depends on how sensitive your ears are. The air-operated Yukon Zip Locker behaves like an open differential until it’s turned on by the driver. When activated, a locking collar slides forward and locks the gears together, transferring equal amounts of traction to both tires. The air locker’s on-off selectability makes them ideal for street-driven vehicles. USA Standard Gear Spartan Helical LSD The gear-type USA Standard Gear Spartan Helical LSD features floating helical-cut worm gears that operate in pockets and mesh together. Under normal driving conditions this type of LSD acts like an open diff. While under acceleration or when wheel slippage occurs, axial and radial thrust is applied to the helical gear pinions transferring more torque to the tire with the best traction progressively as torque is withheld from the tire that is slipping. The Spartan Helical LSD’s advanced 10-pinion design has a strength advantage over an equivalently sized 6-pinion or 8-pinion units because it has more points of contact and a greater surface contact area to deliver optimal load distribution. USA Standard Gear uses forged 8620 grade steel in the case and internals for superior durability. Yukon Re-Gear Kits You can also step up to the plate and upgrade your gears with one of our all-encompassing Yukon Re-Gear Kits. There are two key reasons to change the ring and pinion gears in your vehicle. The first is to regain the lost performance and fuel efficiency of a daily driven vehicle that has been upgraded with larger wheels and tires. The second is to optimize the performance of a rig that is a dedicated off-roader where low-end tenacity and low-speed acceleration are of more importance than operating efficiently at freeway speeds. Yukon’s convenient ring and pinion Re-Gear Kits bundle everything you need to upgrade both the front and rear differentials in one simple part number, saving you tons of time and hassle. These kits feature premium Yukon ring and pinion gears, Master Install Kits with high-quality Timken/Koyo bearings, and all the small parts you’ll need to get the swap done right. End Of The Trail The Dana 30 can be a primetime performer. The key is to know where your going with your truck… literally. Consider how much time it will spend on the street, how much time on the trail, and how intense your trail activity is going to be. Also factor in whether or not you’ll be upgrading to larger tires in the future. Then weigh the pros and cons of swapping your diff. Could be a properly prepped Dana 30 will get you where you need to go and save you money that can be invested elsewhere in your rig… chromoly axles, some bumper and body mods, or perhaps a bitchin’ Yukon Hardcore Diff Cover so it looks the part!. Happy Wheeling. contact us at 866-631-0196
Yukon Gear & Axle Dana 30 Performance Options
The Dana 30 differential has been pulling the front of Jeeps around since the CJ-5s of the early 1970s. Available in high- and low-pinion versions as well as standard and reverse rotation versions, the Dana 30 can be found in Wranglers, Cherokees, Grand Cherokees, and Comanche MJs to name a few. They are also in early Ford Broncos and various AMC applications. Too often the capabilities of this mighty-mite diff are overlooked and enthusiasts swap them out. But the D30 has a huge aftermarket behind it and there are plenty of spares waiting for rescue in junkyards across the country… the D30 is begging to be built! Read this article in Español Thrive Don’t Just Survive If you’re rolling a Dana 30 why not take advantage of its extensive modification potential? It’s a great landing spot for drop-in lockersockers like our Spartan Locker, large-frame lockers like our Yukon Zip and Grizzly units, and positraction limited slip differentials like our Spartan Helical LSD. Spartan Locker Spartan Locker The Spartan Locker is known as a drop-in or lunchbox locker. This product is not a single unit that is swapped into your pumpkin, it is a collection of components that transform an open differential carrier into a locker. Typically, a Spartan Locker consist of a pair of drivers, two side couplers, four alignment pins, four pre-load springs, a hardened cross-pin shaft, a roll pin, and installation wires. Yukon Grizzly Locker and Yukon Zip Locker Large-frame lockers, like the Yukon Grizzly and Zip, replace the carrier as a single unit and their case is constructed from a muchstronger alloy steel compared to the factory carrier. The main difference between these units is operational… the Zip Locker is air operated and the Grizzly is a mechanical unit. Yukon Grizzly Locker Mechanical lockers like the Yukon Grizzly Locker, sometimes referred to as automatic lockers, are always engaged. During normal mild-throttle situations where load is applied to the differential, the unit is locked. When the vehicle is turning, the locker produces a clicking sound as the square-cut side gears move over and past one another. This ratcheting sound can be loud and is why mechanical units may not be best suited for vehicles that spend a lot of time on the street… it all depends on how sensitive your ears are. The air-operated Yukon Zip Locker behaves like an open differential until it’s turned on by the driver. When activated, a locking collar slides forward and locks the gears together, transferring equal amounts of traction to both tires. The air locker’s on-off selectability makes them ideal for street-driven vehicles. USA Standard Gear Spartan Helical LSD The gear-type USA Standard Gear Spartan Helical LSD features floating helical-cut worm gears that operate in pockets and mesh together. Under normal driving conditions this type of LSD acts like an open diff. While under acceleration or when wheel slippage occurs, axial and radial thrust is applied to the helical gear pinions transferring more torque to the tire with the best traction progressively as torque is withheld from the tire that is slipping. The Spartan Helical LSD’s advanced 10-pinion design has a strength advantage over an equivalently sized 6-pinion or 8-pinion units because it has more points of contact and a greater surface contact area to deliver optimal load distribution. USA Standard Gear uses forged 8620 grade steel in the case and internals for superior durability. Yukon Re-Gear Kits You can also step up to the plate and upgrade your gears with one of our all-encompassing Yukon Re-Gear Kits. There are two key reasons to change the ring and pinion gears in your vehicle. The first is to regain the lost performance and fuel efficiency of a daily driven vehicle that has been upgraded with larger wheels and tires. The second is to optimize the performance of a rig that is a dedicated off-roader where low-end tenacity and low-speed acceleration are of more importance than operating efficiently at freeway speeds. Yukon’s convenient ring and pinion Re-Gear Kits bundle everything you need to upgrade both the front and rear differentials in one simple part number, saving you tons of time and hassle. These kits feature premium Yukon ring and pinion gears, Master Install Kits with high-quality Timken/Koyo bearings, and all the small parts you’ll need to get the swap done right. End Of The Trail The Dana 30 can be a primetime performer. The key is to know where your going with your truck… literally. Consider how much time it will spend on the street, how much time on the trail, and how intense your trail activity is going to be. Also factor in whether or not you’ll be upgrading to larger tires in the future. Then weigh the pros and cons of swapping your diff. Could be a properly prepped Dana 30 will get you where you need to go and save you money that can be invested elsewhere in your rig… chromoly axles, some bumper and body mods, or perhaps a bitchin’ Yukon Hardcore Diff Cover so it looks the part!. Happy Wheeling. contact us at 866-631-0196