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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 To 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
ICON Vehicle Dynamics Impact Off-Road Armor For Jeeps
The trail can be rough on your Wrangler. Protruding obstacles conspire to damage rocker panels and underpinnings. Bumpers can take a beating but they also need to do more than sit there. A properly outfitted bumper will increase your approach/departure angle, serve as a tow point for rescue, house additional lighting, and secure your all-important winch. Fortify your JK, JL, or JT Jeep Wrangler with ICON Impact Off-Road Armor from RANDYS. We are offering rocker panels, skid plates, and a number of different front and rear bumper designs. You can also step up your game with upgraded body-mount tire carriers, spare tire delete kits, license plate relocation kits, fender liner kits, and fairlead mounts. ICON Impact PRO Series Body Armor & Slider Kit Low-hanging rocker panels are inherently vulnerable to damage. Protect them with a two-piece Body Armor & Slider Kit. The rocker guards are fabricated entirely of 3/16-inch thick plate steel that has been CNC laser cut and precision brake-formed to match every contour of your Jeep’s body. It attaches directly to the vehicle’s body mounts, protecting against rocks and dings around the door sills. The rock slider provides a defensive railing that slides against rocks, stumps, and other protruding obstacles to keep your Jeep's doors and body sides out of harm’s way. – Ties in to body mounts at the frame, producing a rigid structure – Rock slider also serves as a step to assist entry into lifted Jeeps – Rugged 3/16-inch thick plate-steel construction – CNC laser cut and brake-formed to perfectly match rocker panel contours – Durable multi-stage semi-gloss black powder coat finish Shop Rock Sliders ICON Impact COMP & PRO Series Bumpers High and Tight like a tidy military haircut is one way to look at ICON Impact Series bumpers. These tough, stubby, minimalist bumpers are designed for the hardcore rock crawler who values light weight and maximum clearance. Impact Series rear bumpers are available in three versions; the COMP Series, the original PRO Series, and the PRO Series 2. The big difference is the mounting procedure. All three versions are adept at protecting the vehicle’s rear corners while offering the most possible clearance for navigating tight trails and overcoming obstacles. To install a COMP Series unit, part of the Jeep's frame rails is cut off in order to provide incredible, nearly-vertical departure angles while the PRO and PRO Series 2 are designed with the smallest form factor possible without cutting into the Jeep's frame rails, ensuring you still enjoy phenomenal ground clearance and departure angles all with a bolt-on-and-go installation. ICON Impact bumpers are constructed from 3/16-inch plate steel and shackle tabs are fabricated from one-inch plate steel. In bumpers with integrated tow hitch accommodations, ICON delivers the most convenient, trail-friendly package possible. Impact Front Bumpers Barely wider than the Jeep's frame rails, Impact Series front bumpers allow full turn and full suspension articulation on big-tire rigs while also granting front tires clear access to grip and climb up onto boulders, rock walls, and other extreme trail obstacles. Choose from a number of innovative designs, each mixing in different impact bar configurations, angled shackle tabs, winch mounts, and fog light accommodations. Bumpers are constructed from 3/16-inch plate steel, impact bars are fabricated from heavy-wall DOM tubing, and shackle tabs are made with one-inch plate steel. - Compact, stubby design provides light weight and maximum clearance - Low-profile impact bar protects winch and grille area from trail hazards - Impact bar and stinger made of 1-3/4 inch or 1-1/2 inch by .120 wall DOM tube - Bumpers feature laser-cut plate steel gussets Extreme duty one-inch thick recovery shackle tabs are angled for maximum clearance - Top-mount winch location allows easy access to the drum and keeps the winch out of the mud - Rugged CNC laser cut and brake-formed 3/16-inch thick plate steel construction - Durable semi-gloss black powder coat finish Impact Rear Bumpers Rear bumper can also be ordered in different configurations. Back-up lighting may be provided by a pair of protected, recess mounted 2.5" LED back-up lights (lights sold separately). To provide trailer tow convenience in the most trail-friendly package possible ICON has positioned the tow hitch to tuck up high and tight. ICON bumpers are a great way to add function and style to your rig. - Faceted high-clearance design to maximize departure angle and clearance - Extreme-duty one-inch thick recovery shackle tabs are angled for maximum clearance - Rugged CNC laser cut and brake-formed 3/16-inch thick plate steel construction - Durable semi-gloss black powder coat finish Shop Bumpers
Transfer Case Season 2022
Transfer case season is upon us. As the leaves fall and temperatures drop it’s a clear sign that driving conditions are about to worsen. This is the time of year we rely on our drivetrain more and unit failures tend to go up. This is especially evident around that first snowfall of the season. Zumbrota Drivetrain is ready for the season with many popular tried-and-proven remanufactured transfer cases ready and in stock for purchase. Shop Remanufactured Transfer Cases Transfer Case Breaking Points Sometimes the transfer case will fail when you push the button or it just won’t work at all but it can be hard to tell when things went sideways. Zumbrota’s Sales Manager Josh Linnell says, “most of the time the damage has been done well before you hear anything. Some failures are just a worn part, some are more catastrophic; the result is the same. Transfer cases have a lot of metal-on-metal contact, factor in that most cars and trucks are going to last 200,000 to 300,000 miles nowadays and something as to give. Chains, clutches and/or viscous couplers are some of the common failure prone parts. And I must say, we see a lot that can be prevented by keeping the vehicle maintained.” As with any mechanical system proper maintenance is paramount. “Most units only hold about two quarts of fluid,” quips Linnell. “So, in the environment inside the case there’s a lot being asked of the fluid. On top of that, the transfer case is often overlooked when it comes to checking the fluid level and condition during a routine tune-up so the deck can be stacked against the transfer case.” Linnell indicated that there’s another reason for transfer case problems that might not be apparent at first look. “The other is all four tires having the same diameter, not just all the same size on the side of the tire but the actual diameter of the tire. A difference here causes a load imbalance inside the unit and pre-mature wear.” In-Depth Inspection Protocols Zumbrota has been on the leading edge of gearbox remanufacturing since 1989; they have seen it all. Their process starts with superior inspection techniques. Quality inspections are conducted three times during the remanufacturing process. A pre-inspection ensures the unit is free of case cracks and stripped threads, identifies excessive wear, and catches OEM-related problems that many cores have. The second inspection is conducted during the remanufacturing process to ensure all component parts meet OEM specifications. Items under consideration include, shaft straightness, gear wear, and chain stretch. Then a final post-build inspection is done to ensure the transfer case has been built to strict Zumbrota standards. Unrivaled Proprietary Cleaning Zumbrota’s exclusive Hydro Blast rinse and media-blasting techniques are used on internal and external parts. These initial processes are followed up by a proprietary shot-enhanced deep cleaning that gives the transfer case a like-new look. In fact, many customers call and ask if they’ve been shipped a new unit by mistake. From The Hands Of Craftsman After the initial case inspection, Zumbrota technicians determine which parts have failed or worn and which ones can be reused. Viscous couplers, bearings, and all seals are always replaced. Any common wear items are also replaced. As part of the final inspection, each unit is spun tested to confirm proper shifting and to make sure the transfer case runs smooth and quiet. Each unit is shipped in a high-density plastic tote to help eliminate in-transit damage and make core return an easy remove-and-replace proposition for the customer, be it a shop technician or a DIYer working in his home garage. Shop Remanufactured Transfer Cases When your transfer case fails getting back on the road is critically important. When you buy a Zumbrota transfer case, you’re investing in the confidence, satisfaction, and peace of mind that comes from a company that has been helping people since 1989. Blown Your Diff? Blown out rear end gears are another sign of the times in the dark and challenging winter months. Yukon Gear & Axle’s ready-built dropouts help speed the replacement process. Whether you need to get back on the road or if you’re swapping to more aggressive gears Yukon Dropout Assemblies turn the tedious diff rebuild project into a straightforward remove-and-replace operation. Even better, you can elect to increase your vehicle’s grip by adding a traction adder like a Yukon Dura Grip LSD, Grizzly Locker, Zip Locker, or a spool. These units are pre-assembled, no oily gear wrestling, no setting backlash and preload, no deciphering gear patterns in yellow chalk. Shop Pre-Built Dropouts
Transfer Case Season 2022
Transfer case season is upon us. As the leaves fall and temperatures drop it’s a clear sign that driving conditions are about to worsen. This is the time of year we rely on our drivetrain more and unit failures tend to go up. This is especially evident around that first snowfall of the season. Zumbrota Drivetrain is ready for the season with many popular tried-and-proven remanufactured transfer cases ready and in stock for purchase. Shop Remanufactured Transfer Cases Transfer Case Breaking Points Sometimes the transfer case will fail when you push the button or it just won’t work at all but it can be hard to tell when things went sideways. Zumbrota’s Sales Manager Josh Linnell says, “most of the time the damage has been done well before you hear anything. Some failures are just a worn part, some are more catastrophic; the result is the same. Transfer cases have a lot of metal-on-metal contact, factor in that most cars and trucks are going to last 200,000 to 300,000 miles nowadays and something as to give. Chains, clutches and/or viscous couplers are some of the common failure prone parts. And I must say, we see a lot that can be prevented by keeping the vehicle maintained.” As with any mechanical system proper maintenance is paramount. “Most units only hold about two quarts of fluid,” quips Linnell. “So, in the environment inside the case there’s a lot being asked of the fluid. On top of that, the transfer case is often overlooked when it comes to checking the fluid level and condition during a routine tune-up so the deck can be stacked against the transfer case.” Linnell indicated that there’s another reason for transfer case problems that might not be apparent at first look. “The other is all four tires having the same diameter, not just all the same size on the side of the tire but the actual diameter of the tire. A difference here causes a load imbalance inside the unit and pre-mature wear.” In-Depth Inspection Protocols Zumbrota has been on the leading edge of gearbox remanufacturing since 1989; they have seen it all. Their process starts with superior inspection techniques. Quality inspections are conducted three times during the remanufacturing process. A pre-inspection ensures the unit is free of case cracks and stripped threads, identifies excessive wear, and catches OEM-related problems that many cores have. The second inspection is conducted during the remanufacturing process to ensure all component parts meet OEM specifications. Items under consideration include, shaft straightness, gear wear, and chain stretch. Then a final post-build inspection is done to ensure the transfer case has been built to strict Zumbrota standards. Unrivaled Proprietary Cleaning Zumbrota’s exclusive Hydro Blast rinse and media-blasting techniques are used on internal and external parts. These initial processes are followed up by a proprietary shot-enhanced deep cleaning that gives the transfer case a like-new look. In fact, many customers call and ask if they’ve been shipped a new unit by mistake. From The Hands Of Craftsman After the initial case inspection, Zumbrota technicians determine which parts have failed or worn and which ones can be reused. Viscous couplers, bearings, and all seals are always replaced. Any common wear items are also replaced. As part of the final inspection, each unit is spun tested to confirm proper shifting and to make sure the transfer case runs smooth and quiet. Each unit is shipped in a high-density plastic tote to help eliminate in-transit damage and make core return an easy remove-and-replace proposition for the customer, be it a shop technician or a DIYer working in his home garage. Shop Remanufactured Transfer Cases When your transfer case fails getting back on the road is critically important. When you buy a Zumbrota transfer case, you’re investing in the confidence, satisfaction, and peace of mind that comes from a company that has been helping people since 1989. Blown Your Diff? Blown out rear end gears are another sign of the times in the dark and challenging winter months. Yukon Gear & Axle’s ready-built dropouts help speed the replacement process. Whether you need to get back on the road or if you’re swapping to more aggressive gears Yukon Dropout Assemblies turn the tedious diff rebuild project into a straightforward remove-and-replace operation. Even better, you can elect to increase your vehicle’s grip by adding a traction adder like a Yukon Dura Grip LSD, Grizzly Locker, Zip Locker, or a spool. These units are pre-assembled, no oily gear wrestling, no setting backlash and preload, no deciphering gear patterns in yellow chalk. Shop Pre-Built Dropouts
ICON Alloys’ Revolutionary InnerLock Bead Retention Technology
Go low, get more grip. Experienced off-roaders know dropping air pressure can transform your trail running experience. The benefits include improved ride quality, especially over undulating washboard surfaces, a larger contact patch for increased traction, and the ability to grip and climb rocks and other jagged obstacles. However, running at very low pressures also increases the risk of de-beading the tire during extreme side loads or aggressive driving. While traditional beadlock wheels address this issue by clamping the tire’s bead, they also need frequent maintenance, require specialty tools/parts, increase rotational mass, and are NOT legal for on-road use. Get a “best of both worlds” solution with ICON Alloys’ patented InnerLock technology. It uses a robust bead-retention system to keep the tire bead secured to the wheel while also being fully DOT compliant and street legal. The InnerLock system uses a series of O-ring sealed, hardened alloy pins that are threaded on the inner side of the tire bead to create a barrier that prevents the tire from unseating during extreme side loads. Additionally, InnerLock wheels are lightweight, strong, don’t require bolt retorquing, and are street legal for the ultimate blend of on-road safety and off-road performance. The InnerLock system is current available on ICON Alloys Rebound PRO, a dynamic eight-spoke design that can presently be ordered in 17-inch sizes in a variety of bolt patterns, and colors. - A stylish street-legal beadlock wheel - Uses ICON Alloys patented InnerLock technology - InnerLock features removable, reusable, and replaceable bead retention pins - Quick, easy, and safe tire installation and removal - Works without the need for any shims or special tools - Application-specific dimensions optimize vehicle dynamics and tire clearance - Reduced un-sprung weight and rotating mass improves handling - Rebound Pro wheel sports a stout 3,200-pound load rating Shop ICON Alloys