Replacing the rear differential gasket is straightforward once the oil is drained. Replacing or rebuilding a differential are two other options for fixing differential noise, and both can take several days to accomplish. Let’s take a look at the magic of the rear differential and the problems that arise from rear differential noise.“. As often the noise resonates through the chassis, pinpointing the source of it is very difficult. This would make turning difficult and with a high probability of losing control. Most are normal while the vehicle is in motion. Immersing a hot differential as you drive through a deep puddle, creek, or unload a boat, can cause the housing to crack or a seal to leak. Check to see if there are any leaks at the differential. Removing and replacing the pinion seal or side seals are more complex. For example, howling of gears is a sure sign of wearing. Here are some noises you may hear when your differential needs service, and what could cause the sounds. Then grab the wheel and wiggle it back & forth. Having teeth affected on a single pinion gear may not ruin your differential completely and if caught in time you might be able to slowly reach a mechanic shop without a platform. All vehicles make noises when they drive, and almost all have at least one differential. All unusual or strange noises produced by the driveline while driving have a root cause and should be thoroughly investigated to prevent serious damage to the vehicle or the operator. If the pinion bearings are the problem, they create more of a whirring noise than a rumble because it turns several times faster than the carrier assembly. How to Fix a Noisy Differential. Lubricant life depends a lot on the temperature it reaches. The differential is the final end mechanism that enables the creation of torque in the crankshaft before it is distributed through the transmission, to the drive shaft, and then to the wheels. They mesh with the side gears at 90° to drive each axle, transferring drive rotation but preventing flexing of the co-axial axle. Usually this happens when after different circumstances a gear moves a little inside the differential or the contact pattern was never adjusted perfectly, resulting in a slight noise when the teeth mesh. This delivers the same torque to both sets of axles, which is why steering at slow speeds is more difficult. Regular clunking every few feet can also be an indicator of a broken pinion gear and/or chipped and damaged ring gear. I created this blog to share what I learned and to make it easier for you to improve your quiet space too. Usually once your differential goes bad you might experience any of the following: The rear differential is made up of many gears with teeth entwined with each other. • A “Rumble” while cornering or turning may indicate bad wheel bearings. If it is making unusual noises, then it is warning you that something isn’t right. Reason is that the load on the gears makes it harder for the teeth to slide across each. If nothing is leaking, but the vehicle has between 30,000 and 60,000 miles for front differentials or 30,000 to 50,000 for rear ones, the fluid should be changed since the oil will break down over time. Differentials are finely tuned mechanisms that seldom need repair; they can last for hundreds of thousands of miles without fail. The two pinion or spider gears are attached to the ring gear and rotate with it between the beveled side gears at the end of each co-axial axle, rotating them and delivering drive power to the wheels. If a rebuild or used diff is a possibility, it could save up to 50% over a new differential. If you wait too long to repair the differential and the inside looks like a grenade has exploded inside with broken metal teeth and pieces resembling shrapnel, it may be less expensive to replace the differential. Broken teeth on the axle gear can result in complete loss of power when turning in any direction and eventually reaching a point where the gears don’t engage at all anymore, bringing the car to a complete standstill. Clunking and banging noises on the corners can be due to lack of sufficient posi-traction lubrication, broken spider gears, or worn posi-traction or limited-slip clutches. Very well explained. The longer you wait, the more costly the repairs may be. The differential is made up of different gears that split the rotation of the engine power to the left and right wheel assemblies. I’ll probably look at trading my Ford and going back to GM trucks. Vehicles make many sounds. What is a Differential on a Car and How It Works, What Are the Causes of Differential Noise, Whining Noise on Acceleration/Deceleration. Well this makes a world of a difference when turning. Repairing a differential is a dirty and messy task. Removing them requires first removing the axle shaft(s), and then removing and replacing the leaky seal(s), before carefully reassembling everything. If the axles weren’t split, both wheels would spin at the same rate, which is problematic when cornering – damaging the shaft, stripping gears, or causing the vehicle to spin out of control. This is or was a very informative explanation of what I think is my problem with a 2016 F150 with 99,000 miles. This also increases load on the carrier bearings making them prone to failure also (and they too get really noisy).Sometimes this issue evolves into experiencing noise during coasting as well.Interestingly sometimes differential noise on acceleration appears not because the teeth are misaligned but because the user got stuck and forced the car to get unstuck. You want the drive wheels off the ground, and blocks behind non-drive tires if on the ground. Simply put, the differential allows each wheel to be independent from the other while still sending power to both of them. Removing and replacing any gears inside the diff isn’t easy, or cheap. See more from SKF. Once the gears are exposed, it is easier to note what actually needs to be repaired and if your diagnosis was accurate. However, once the noise gets bad, rebuilding or replacing the differential may be the best way to fix the noise. It’s a messy job and should be done on a hoist or jack stands. When applied, the gear oil in the differential carries this Engine and Metal Treatment to the asperities of the metals to form a covalent, galvanic bond on it. This article does not have the information I am looking for. Generally, worn out pinion bearings can create whirring noises at various speeds, be it may during deceleration and/or acceleration. It can quietly carry out its purpose for thousands of miles, but when it starts making noise, maintenance, and repair are necessary. As a bearing begins to wear, friction increases and metal material is worn down making often bad noises until it finally fails. Often the noise get louder as the cars speed or load increases. If accelerating and the howl is accompanied by a rumble or whir, it could be from a worn gear set or worn pinion or ring gear or bearings. Diagnosing a front or rear differential noise and determining it isn’t from a failing wheel bearing isn’t always easy. This noise can come off as popping/banging or binding. Hi, I’m Eugene. Your suggestions and comments are appreciated. Reassemble and refill the differential oil. But there are times when a noise coming from under the car can be a serious matter. Does your auto make a grinding or howling noise when driving? Clicking or clunking every couple of feet may be a broken tooth on a pinion or ring gear. If the vehicle is in neutral, you should be able to spin one drive wheel while the other is held. Manufacturers did not create these complex assemblies with such loads in mind. It the differential would not be present, we would have wheels locked together at the same speed in a turn. Just a few parts to replace will cost significantly less than lots of parts to replace. But how exactly does the motion of the piston or crankshaft convert to the rotational motion of the wheels? Water in the differential can play havoc with the lubricant and damage gears and bearings. You want to listen to the noise. The cost of replacing a rear differential depends on the degree of the repairs that need to be done. Aftermarket parts may save 30% to 40% over OEM parts, and reduce costs. Hearing the noise when accelerating may be due to worn or loose axle or yoke splines, spider or U-joint wear, or differential backlash noise. It would be best to not leave these signs ignored as each extra mile done under these circumstances might increase your repair bill in the future. Remove the seal around the yoke and replace it without damaging the new one. Besides turning, other issues could arise from the drivetrain as it would be exposed to high forces. If you can’t, there’s a problem. The side seals prevent the oil from seeping into the brakes. Differentials are complex mechanical elements and changing a gasket or pinion seal comes with a significantly lower cost than having to rebuild the entire differential or swap it out completely. Once they get hot, the gear lube’s lubrication properties are lost. A helpful review focusing on drivetrain components for the ASE PS2 Test. Drives is advised to pull over in order to prevent the possibility of loosing control. Two wheels on a drive axle without a differential in the middle would result in both wheels receiving the same power at all times. Repair of the differential is usually recommended to be left in the hands of professionals because of the complexity of the system. Gear teeth tend to break in seats of 2-3 and with every broken tooth the length of the skip and the violence of engagement increase, producing more severe noise and vibration. A rear differential pinion seal necessitates the removal of the yoke where the driveshaft and diff meet. When one wheel is spinning slower on a curb, the mechanism will keep driving the other wheel without any skidding, binding or jerking. Having a chipped or missing high spot on a gear tooth sounds closely similar to a broken gear except that the rear differential noise only happens while accelerating or decelerating. If you suspect it is a failing differential based on the sound or handling, put the vehicle up on jack stands or a hoist. I had never in driving General Motors pickups for 27 years had a bad differential. Considering both affect the handling and safety of your ride, it’s best to determine what needs repair and fix it. A new differential will run an easy $1500 to $4000 installed, while a rebuild (used) will set you back between $700 and $2000 installed. Why should you care? Boost Performance Products Hopefully, you have a better understanding of what differential does, how to diagnose different noises, and how to stop differential noise. It may be cheaper to replace the differential. Depending on what teeth are affected you might experience these vibrations at all times (if the chipped tooth is on the pinion or outer ring gears), when turning in either direction (if the broken tooth is on the pinion gears aka spider gears) or just when turning in one direction (if there’s a chipped tooth on the axle gears).If you have multiple broken teeth you’ll certainly hear rattle or thunk sounds. To put it simply, this mechanism is the one that decides the speed and the frequency of the turning of the axle and wheels in relation to the turning of the drive shaft. A whining or howling differential noise on accelerating or decelerating may be caused by a loose gear inside the differential. However, if you experience clunking, grinding, whining, or another bad differential sound when accelerating, decelerating, or cornering, it could indicate that something isn’t right in the differential. We explain what a differential is and provide a simple description – we don’t explain all differential types. • A steady vibration that increases with the vehicle’s speed can be caused by worn u-joints or an out of balance driveshaft. Open Mon-Fri 9:00am - 5:00pm Rumbling and whirring noises at speed over 20 mph, moreover, can be the result of worn carrier bearings. Tests have shown that towing a trailer at 55 mph on a 3.5% grade can result in temperatures up to 370°F where the lifespan of gear oils is best measured in minutes, not miles. When issues start to occur, a howling sound might appear from the rear of your truck while driving.