Vehicles make mobility easy for us. However, to continue enjoying the benefits of possessing a car, it is essential to understand its maintenance; otherwise, not understanding bad pinion-bearing symptoms and other faults can lead to a disaster in your vehicle.
Unexpected breakdowns of vehicles do not suddenly occur; there are usually noticeable symptoms before any sudden breakdown. If you notice signs of a faulty part of your vehicle, you should seek the attention of a professional mechanic to fix the problem.
Driving with a bad pinion bearing can be frustrating; from the whirring sound to the damages it causes on the differential, driveshaft, and transmission in your vehicle are all signs of a worn-out pinion bearing.
If you are wondering, “What is a pinion bearing?” and the signs to look out for in a bad pinion bearing, this article is to expose what it feels like to drive a vehicle with a bad pinion bearing.
What is a Pinion Bearing?
A pinion is a round gear, usually the smaller amongst two meshed gears, used in various applications, such as drivetrain and rack and pinion systems.
The rack and pinion gear set perform two primary functions: the reduction of gears, which enables the steering wheel to turn the wheels easily, and the conversion of the steering wheel’s rotational motion into linear motion, which helps the wheels of the vehicle turn easily.
A pinion bearing helps the smallest gears in the differential work efficiently. Differentials consist of a series of cogs and gears, and it is the smallest gears that enable one wheel to rotate faster than the other safely.
Meanwhile, the pinion nuts help to hold the pinion gear and the driveshaft yoke together securely.
How does a pinion bearing work?
The pinion bearing’s job is to support the weight of the differential and allow it to rotate smoothly. The pinion bearings are positioned around the pinion gear shaft within the differential.
This shaft connects to the pinion gear, which meshes with the ring gear to transfer rotational force from the driveshaft to the wheels.
The pinion bearings support the pinion gear in the differential by holding the pinion gear in precise alignment, enabling it to mesh smoothly with the ring gear to transfer power from the driveshaft to the wheels.
These bearings provide a low-friction surface that helps reduce wear on the differential gears and allows them to rotate more smoothly.
Common types of pinion bearings
Pinion bearings come in various types, each suited to different applications and operating conditions.
Ball bearings: Featuring spherical rolling elements, ball bearings excel in low friction and high-speed capabilities, making them ideal for precision instruments and light-duty vehicle steering systems where smooth rotation and rapid response are critical.
Roller bearings: Roller bearings utilize cylindrical rolling elements, providing 40–60% higher radial load capacity than ball bearings, along with enhanced shock and vibration resistance. Commonly used in medium-duty drive shafts and gearboxes.
Taper roller bearings: These bearings combine the benefits of both ball and roller bearings, featuring tapered rolling elements that can accommodate both radial and axial loads with 30% greater load capacity than standard roller bearings. Widely applied in heavy-duty truck differentials and construction machinery slewing rings under high-load, high-speed conditions.
Where Is A Pinion Bearing Located?
The pinion bearing is located where the drive shaft meets the differential. This bearing permits the drive shaft to rotate freely, allowing the differential to transmit power to the wheels.
If the pinion bearing malfunctions, numerous problems could occur. For instance, the car may move erratically if the driving shaft cannot rotate properly. Additionally, the car may stall or slow down if the differential cannot properly transfer power to the wheels.
What are the Bad Pinion Bearing Symptoms?
The most common bad pinion bearing symptoms are listed below:
- Whirring Noise
- Humming Noise
- Excessive Vibrations
- Grinding Noise
- Tire Damage
Let us see these symptoms in detail:
#1. Whirring Noise.
Whirring noise from the differential is usually one of the first signs that something is wrong with your pinion bearings.
This noise is caused by the metal balls inside the worn-out pinion bearing beginning to wear down and become damaged. As they become more damaged, they will generate more friction, and this will cause the bearing to make more noise.
#2. Humming Noise.
Another symptom of pinion bearing failure is a humming noise from the differential. This noise is caused by the damaged bearings failing to support the differential weight properly. As a result, the differential will begin to wobble and make a humming noise.
#3. Excessive Vibrations.
If your pinion bearings fail, you may also notice excessive vibrations coming from the differential.
These vibrations are caused by the damaged bearings allowing the differential to wobble. This can cause a lot of wear and tear on other parts of your drivetrain, so getting it checked out as soon as possible is important.
#4. Grinding Noise.
If your pinion bearings are completely worn out, you may hear a grinding noise from the differential. This is caused by the metal-on-metal contact between the differential and the bearings. If left unchecked, gear grinding can cause serious damage to your drivetrain.
If the noise is severe, it could indicate a serious problem that requires immediate attention. However, if the noise is more subtle, it may not be cause for alarm and could simply indicate that the bearing needs to be lubricated or replaced.
#5. Tire Damage.
Another symptom of pinion bearing failure is tire damage. This can be caused by the vibrations from the failing bearings causing the tires to lose contact with the road. This can lead to uneven wear on the tires and can eventually cause a blowout.
What Causes Pinion Bearing Failure?
Pinion bearing failure is traceable to some of the following causes.
#1. Failure from Lubrication.
About 80 percent of pinion bearing failure is traceable to inadequate lubrication. Sometimes, it could be insufficient lubrication, inappropriate lubricants, or degradation of lubricants due to excessive temperature.
#2. Corrosion.
Corrosion is another cause of pinion-bearing failure. Corrosion could result from acid, moisture, broken down or low-quality grease, etc.
#3. Contamination.
The entrance of unnecessary/alien substances such as dirt, dust, abrasive grits, etc., can contaminate the pinion bearing, resulting in its failure.
#4. Misalignment.
Misalignment can result from bent shafts, out-of-square clamping nuts, out-of-space shaft shoulders, out-of-square spacers, and improper installations. This error can lead to overheating and separator failure.
#5. Improper Mounting.
Pinion bearings should be mounted with a press on the floating ring. Mounting bearings on shafts by applying blows or pressure on the outer race, poor finish on the bearing seat, etc., can result in pinion bearing failure.
#6. False Brinelling.
False brinelling results from lack of rotation in the bearing, which disables fresh lubricants from returning to the spot, and a rapid movement of the balls while the vehicle is idle.
#7. Fatigue.
Overloading, excessive preload, the tight inner ring fits, and excessive bearing above lifespan can result in fatigue, which later results in pinion bearing failure.
#8. Overheating.
Improper lubrication and excessive temperature can cause overheating. High temperature can cause loss of lubricating oils from grease, resulting in dryness that causes the bearing to seize.
#9. Excessive Loads.
Exerting too many loads than necessary on a bearing can also cause pinion bearing failure.
How Can You Fix Bad Pinion Bearings Noise?
You can fix bad pinion bearings noise by lubrication, less use of your car, avoiding corrosive elements, carrying out routine maintenance, and better driving habits.
Sometimes, you must resort to consulting a professional for proper installation in order to resolve the problem.
#1. Reduce Driving.
One of the most efficient methods to reduce the chances of having bad pinions is to reduce your driving frequency.
Excessive use of your vehicle can reduce the pinion’s quality of performance. Less driving reduces the differential load and eliminates the chance of experiencing noise.
If your bearings already make an irritating sound, reduced driving stops the noise. However, this doesn’t solve the root cause, so you must consult a professional mechanic for a proper diagnosis.
#2. Avoid Corrosive Elements.
Another way you can fix the bad pinion noise is to avoid driving during harsh weather conditions. For instance, rain or snow exposes the belly of your car to salt, toxic chemicals, and moisture. These materials are capable of causing rust to your undercarriage.
Hence, avoid driving in such conditions to limit the damage to your undercarriage. Additionally, you should always park your vehicle in a cool, dry space. Unfavorable temperatures also aid corrosion, so avoid parking in damp or humid areas.
#3. Proper Lubrication.
Pay attention to proper lubrication if you want to stop noise from your piston bearing. Ensure you lubricate your bearings on a regular basis.
Also, make sure you use only high-quality lubricants for your bearings. Consult your owner’s manual or a licensed mechanic to know what type of lubricant is right for your pinions.
Despite what you may think, over-lubricating can cause problems for your gear system. Hence, focusing on your fluid level is best to avoid an imbalance.
#4. Carry Out Proper Installation.
Proper installations go a long way in troubleshooting the problem of noisy bearings. Improper installation is one of the major causes of misalignment and incorrect mounting. This will lead to overheating and wear.
If you’re unsure how to install a bearing, consult a professional rather than doing it yourself. A professional mechanic will do the correct installation to avoid future problems.
#5. Avoid Overloading.
Unless designed for hauling, you should only use your car for towing or transporting a few people. If you must haul heavy items, ensure they fall within the bearing’s capacity. Hence, it would help if you only used bearings with a high load rating for efficiency.
Another way to reduce overloading is to ensure your bearings are the right size. The wrong size can give way to excess weight. Reducing the load on your differential can fix the rear differential noise from damaged bearings.
#6. Adjust Driving Habits.
You may also need to adjust your driving habits to fix the noise problem in your bearings. You should drive with a sense of responsibility and maintain a safe and constant speed.
Avoid excessive acceleration or sudden brakes. You should also reduce your foot pressure on the gas pedal and drive with less speed over bumps.
Make use of the cruise control feature whenever you can. Pay attention to your speedometer to ensure you drive at a constant but safe speed.
#7. Carry Out Routine Maintenance.
To fix noisy bearings, perform routine maintenance on your bearing and gear system. Inspect your bearing as often as you can, searching for visible damage.
Make sure your bearings are well aligned and not corroded. Make regular adjustments to your bearings where necessary. You don’t have to wait until there’s an issue with your bearing before you service it.
If you haven’t used your vehicle for a while, a lack of rotation can cause your bearing to be noisy when it becomes active. Hence, if your car isn’t in motion, you should continue lubricating your bearings so they don’t get too rusty.
#8. Repair or Replace Defective Components.
If you find worn or damaged parts in your gear system, you should repair or replace them immediately.
Depending on the part you are replacing or repairing, you can do it yourself if you have the right tools. You must first lift your vehicle with a lifter to replace your bearings.
After that, you must remove the back axles, flange, propeller, and wheels. Next, use a cutoff tool to remove the pinion-bearing compartment from its cage.
Remove the old bearings and cut open a channel in the inner race of the compartment. Place a chisel on the open channel and hammer it.
Use a beaming press to install the new bearings. Reinstall the axles, propeller, flange, and wheels.
After that, tighten the pinion nuts and test-drive your vehicle. If no weird noise reoccurs, you have installed your new bearings with success. You may refer to your owner’s manual to locate specific parts during installation.
You should note that replacing bearings can be very technical. It also requires a high level of expertise to avoid complications. We advise that you consult a professional mechanic or service center to do the repairs in time.
How to Replace a Bad Pinion Bearing?
Here’s a quick guide on how to replace a bad pinion bearing in your car.
#1. Preparation.
Park your car on a level surface and engage the emergency brake. Place jack stands under the frame of the vehicle on both sides to support it. Remove the wheels on the side of the vehicle you will be working on.
#2. Unbolt differential from the yoke.
You will need a socket wrench to remove the bolts that hold the differential to the drive shaft yoke and pinion nuts. There are typically four bolts, two on each side. Remove these bolts and set them aside.
#3. Remove differential cover and drain oil.
Once the bolts are removed, you can take off the differential cover. Be careful, as some oil will still be left in the differential. Use a drain pan to catch this oil and dispose of it properly.
#4. Inspect bearing and gears for damage.
Now that the differential is open look at the gears to see if there is any damage. If there is significant damage, it may be necessary to replace the entire differential.
However, if the damage is limited to the pinion bearing, it can usually be replaced without replacing the entire unit.
#5. Differential adjustments.
While you are working on the differential, you must keep a check on the four types of adjustments involved. These include preload, backlash, ring gear mesh pattern, and pinion depth. You can readjust these by turning the adjusting screws with a screwdriver.
#6. Prepare new parts.
Before you begin reassembling the differential, it is important to prepare the new parts. This includes cleaning all parts with solvent.
#7. Install pinion bearing and adjust pre-load.
You must install the new pinion bearing in the pinion bearing cage with a pinion seal. Once it is in place, use a torque wrench to adjust the pre-load. This should be done according to the manufacturer’s specifications.
#8. Install carrier bearings and races.
Install the new carrier bearings and races in the differential. Again, make sure to follow the manufacturer’s specifications for the proper torque.
#9. Reinstall the differential cover and fill with oil.
Once everything is back in place, you can reinstall the differential cover and fill it with oil. Be sure to use the proper type and amount of oil specified by the manufacturer.
#10. Test drive.
Before you put the wheels back on and take your car for a spin, it is always a good idea to test drive it first. This will help ensure that everything is working properly.
If you follow these steps, you should be able to replace a bad pinion bearing in your car without too much trouble.
How Long Can I Drive With Pinion-Bearing Noise?
It’s crucial to get your car checked out right away if you notice pinion-bearing noise. You might be able to keep driving for a short while, depending on how loud the noise is.
However, it’s essential to get your car repaired straight soon if the noise is loud or ongoing. It’s essential to have a pinion-bearing noise diagnosed so that the required repairs may be made because there are numerous potential causes for pinion-bearing noise.
It’s practically hard to predict how long you can continue to drive with pinion-bearing noise.
Cars with rear-wheel drive and rack and pinion steering systems both use pinions. They are small gears that speed up the rotation of bigger gears, and pinion bearings improve the efficiency and smoothness of that revolution.
You are hearing the bearing, which will begin to make loud whirring noises when it wears out. The steering wheel can be slightly more difficult to turn or result in early tire wear if the pinion bearing entirely fails.
It occasionally even has the potential to harm your driveshaft, differential, or gearbox. Even if that’s not always the case, you shouldn’t take a chance on a blown pinion bearing damaging other parts when it fails.
Important Tips and Tricks for Long-Life Pinion Bearings
Understanding the causes of pinion bearing failures and the symptoms of bad pinion bearings is a significant advantage for ensuring long-life pinion bearings.
However, you don’t have to wait until you observe the symptoms of your bad pinion bearing. It is better to take preventive measures to ensure that your pinion bearing lasts longer.
The following are some essential tips and tricks for long-life pinion bearings.
- Proper lubrication: It is essential to use the appropriate or recommended lubricant for pinion bearing to ensure its longevity. Avoid loss of grease and pay necessary attention to recommended intervals for an oil change.
- Careful mounting: Endeavor to follow proper mounting instructions provided by your vehicle manufacturer or vehicle experts when mounting bearings.
- Keep corrosive fluid away: Ensure to keep corrosive fluids, such as acid, water, etc., away from the bearing area to avoid corrosion.
- Reduce loads: Ascertain the maximum amount of load the pinion bearing can carry and stick to it, or use a bearing with greater capacity for loads.
- Carefully store bearing before use: Make sure you store bearings in a dry environment at room temperature. Ensure to cover bearings to keep them clean during storage. Do not unwrap to expose until you are ready to use, and then move them to the installation site when they are ready for use.
How Much Does It Cost to Replace a Bad Pinion Bearing?
The parts to replace a bad pinion bearing are not too costly at around $70. A total seal replacement will probably be between $240-$290.
Don’t forget about labor costs! Often labor costs are most of the mechanic’s bill. Depending on their hourly rate, labor could be between $170-$220. The total bill will probably be less than $500.
FAQs.
Q: What happens when a pinion bearing goes bad?
When a pinion bearing goes bad, one foremost occurrence is the noticeable whirring noise it produces, vibrations, gear grinding, and tire damage.
Q: How much does it cost to replace a pinion bearing?
The replacement of a pinion bearing would cost an average of $239 – $286. Parts are estimated to cost about $66 – $68, while the labor costs would be around $173 – $218.
Q: What noise does a bad pinion bearing make?
A bad pinion bearing makes a whirring noise at all speed levels, during acceleration or deceleration. Instead of rumbling, a bad pinion bearing whirs due to its turning speed, which is a lot faster than the carrier, depending on the gear ratio.
Q: What does a bad rear axle bearing sound like?
A bad rear axle bearing produces a loud clanking, clicking, or clunking sound when you put your vehicle into gear. These sounds are usually produced on the side with the faulty axle bearing, and the sound increases whenever you try to make a fast or sharp turn.
Q: How do you remove a pinion bearing?
If you are experiencing differential backlash symptoms or signs that your pinion bearing is worn out and you need to remove a pinion bearing, the following steps can make the process easy for you.
Step 1: Lift the vehicle with a four-post or two posts lifter, as the case may be. Lose the propeller and the flange. Remove the wheels and the rear axles.
Step 2: Use a cutoff tool to cut the pinion-bearing cage. Then remove the cage and the bearings. After that, carefully cut a channel in the inner race, which is pressed on the carrier, while ensuring not to cut into the carrier so that the process is not damaged.
Step 3: Put a chisel in the channel you have created by the cut. Then strike it with a big hammer so that the inner race can break. The inner race will either loosen and fall off or break off immediately, depending on the force exerted on the chisel. However, you should do it with care.
Step 4: Get a two-by-four block of wood, place the opposite end of the carrier on the block of wood, install the new bearing on it as far as necessary manually, and ensure that the placement is straight enough.
Then drive the bearing on with the pipe and the big hammer. Hit it down until everything fully sits on the inner flange.
Q: How do you fix a loose pinion bearing preload?
If you are experiencing loose pinion-bearing preload symptoms, simply remove shims in order to tighten the bearing against the races and then increase the pinion-bearing preload.
Final Words
Why should you risk total damage to your vehicle when you can easily ascertain bad pinion-bearing symptoms?
This article has exposed the need for you to carry out adequate maintenance or repair on your vehicle when necessary. The causes of pinion-bearing failure and its symptoms have also been dealt with.
Now, you may not have to ask, “How do you know if your pinion bearing is bad” anymore. You need to examine your vehicle whenever you find any of the symptoms discussed above and then take necessary measures to rectify the problem by changing the bad pinion bearing.