The alternator bearing is a crucial component within the alternator, responsible for supporting the rotating shaft and ensuring smooth operation of the charging system in your vehicle. Over time, this bearing can wear out due to factors such as age, lack of lubrication, or exposure to high temperatures and contaminants.
When the alternator bearing begins to wear down, it often manifests as a persistent squeaking or grinding noise. The simplest method to fix a squeaky alternator bearing involves lubrication. Lubricating the bearing will temporarily aid in noise reduction but won’t solve the underlying problem. The best fix is alternator bearing replacement.
In this guide, we shall be discussing different methods on how to fix a squeaky alternator bearing.
Why Is My Alternator Bearing Squeaking?
- Not Enough Lubrication: Bearings must have enough lubrication to operate smoothly. If the alternator bearing is not properly lubricated or the oil has degraded, it might cause greater friction between the bearing surfaces, resulting in squeaking noises.
- Wear and tear: The alternator bearing wears out naturally over time as a result of constant use. Grinding or squeaking sounds can be the result of the bearing failing due to continuous rotation and stress.
- High Temperatures: The alternator may experience high temperatures due to the harsh conditions found in the engine compartment. Overheating may accelerate the material’s deterioration and wear, which might lead to strange noises or squeaks from the bearing.
- Manufacturing Defects or Design Flaws: In some cases, manufacturing defects or design flaws in the alternator’s components, including the bearing, can contribute to premature wear and, consequently, produce squeaking or grinding sounds.
How Do I Know If My Alternator Bearings Are Bad?
Alternators are responsible for generating the power needed for lights, among other electronics in your car. The alternator bearings keep the rotor in the alternator moving so enough power is generated.
Therefore, if you notice a drop in power, you should have your alternator checked. In addition to the low power, you will also hear a squeaky irritating noise if the bearings malfunction. If you experience these two, take your car to the mechanic as soon as possible.
How To Fix a Squeaky Alternator Bearing?
Now that you know how what makes an alternator bearing squeak, there are ways on how you can inspect them, let have a look at different ways on how you can fix.
1. Replace The Bearings
If the bearings are worn out, the easiest way to fix the squeak is by replacing them. Below is the process to follow when you want to replace the bearings.
Shut the engine off: You can only know what to do with the alternator bearing if you know its condition. This is why a physical examination is important. While checking, ensure that the engine is off. Putting your hand in the alternator when the engine is running can lead to injuries, so you want to be careful about that.
Loosen the belt: Once the engine is off, raise the hood of your car and locate the fan belt. Remove the belt to have a better view of the alternator bearings.
Inspect the bearings: Now that you can see the bearings, it is easy to diagnose the problem. The alternator rarely malfunctions, so the first place you should check is the bearings.
You test the bearings but rotating the alternator with one hand as you touch the bearings with the other hand. In case you hear the grinding noise as you rotate the alternator and the bearing feels rough to your fingers, then you have found your problem. Worn-out alternator bearings tend to be rough or course, which explains why they make that much noise as they rotate.
Replace the bearings: If the bearings are worn out, you have no choice but to replace them. However, getting bearings to match your alternator can be quite a task, and even the replacements will not last as long. For a temporary solution, you can ask your mechanic to get bearings for your alternator.
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2. Replace The Alternator
New bearings are just a temporary solution. Eventually, you need to buy the whole unit.
While the cost of an alternator might be higher than that of the bearings, it is a worthy investment. A good alternator will offer exemplary performance for five-plus years, so you might want to consider how long your current piece has served you.
Replacing the alternator can be somehow complex if you don’t have experience in the same.
It is wise to engage a mechanic who will ensure that it is fixed right and all other parts are in perfect condition.
Below is a step-by-step guide on how to replace an alternator:
- Unplug the negative battery terminal.
- Get the belt tensioner loose.
- Remove the serpentine belt by loosening it.
- Take off the connectors or electrical harness.
- Remove the alternator by loosening the screws.
- Make sure the replacement alternator fits and lines up with the anchor points before installing it.
- Put on the new belt you purchased.
- Verify that the belt is correctly tensioned.
- Reattach the battery’s negative cable.
3. Tighten The Loose Bolts
If the alternator bearing seemed fine when you checked them, you should check if the alternator is fitted correctly.
Sometimes, the bolts holding the alternator may come loose. This is caused by car vibrations as you drive, especially on rough surfaces. With a basic socket set, you can quickly tighten the bolts and rectify the squeak.
4. Replace the Alternator Belt
An alternator belt, also known as a drive belt, serpentine belt, or accessory belt, is a crucial component in a vehicle’s engine that drives multiple peripheral components, including the alternator. It’s a continuous loop of rubber material reinforced with fibers or cords to provide strength and durability.
It is also possible that the alternator belt is worn out. While modern belts are designed to last, they will eventually weaken over time and require replacement.
To see whether the belt is the problem, check it for any physical sign of wear. Unlike the old belts that used to tear, modern belts just weaken at specific points.
If you see weak points, remove the belt and remove it. The process is easy, and you can easily order an alternator belt online. See my recommendation for the quietest serpentine belts on the market.
Before removing the belt, take a photo of the set-up to know what goes where when fixing the new belt.
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Replacing the alternator belt involves several steps, and it’s essential to follow the specific procedures outlined in your vehicle’s manual. Here’s a general guide on how to replace the alternator belt:
Tools and materials you may need:
- New alternator belt (make sure it matches your vehicle’s specifications)
- Wrench or ratchet and socket set
- Belt tension gauge (optional, but useful for proper tensioning)
Park the vehicle on a flat surface. Switch off the engine and make sure it’s cooled down before starting work. Consult your vehicle’s manual to locate the alternator and the belt routing diagram. This diagram shows how the belt wraps around various pulleys in the engine.
Use a wrench or ratchet to loosen the tensioner pulley bolt or adjusting bolt. This will relieve tension on the belt, allowing you to remove it from the pulleys. Carefully slide the old belt off the pulleys. Take note of the belt’s routing for installing the new one.
Referencing the belt routing diagram, loop the new belt around the pulleys, following the correct path. Make sure it sits properly in the grooves of each pulley. Use the tensioner pulley or adjusting bolt to apply tension to the new belt. Ensure it’s not too loose or too tight. Refer to your vehicle’s manual for the correct tension specifications.
Inspect the alignment of the belt on all the pulleys. It should sit squarely in the grooves without any twists or misalignment. Once the belt is properly aligned and tensioned, tighten the tensioner pulley or adjusting bolt to secure the belt in place. Double-check the tension to ensure it’s within the recommended range.
Start the engine and let it run for a few minutes. Listen for any unusual noises and visually inspect the belt to ensure it’s running smoothly on the pulleys. If needed, make minor adjustments to the belt tension to achieve the optimal setting. Recheck alignment and tension after running the engine.
5. Relubricate the Squeaky Alternator Bearing
It is possible to lubricate an alternator, but there are a few things to take into great consideration:
First and foremost, lubricant choice is important. There are various lubricants on the market, and it’s crucial to use the one meant specifically for alternators. The product label usually specifies the type of lubricant, how often it needs to be changed, and how much of each. It’s important to remember that combining different kinds of lubricants can lead to damage.
Second, how the lubricant is applied is important. It is advised to use a grease gun designed especially for relubricating alternator bearings. This ensures relubrication is neatly applied correctly and prevents contamination.
Furthermore, the storage environment of the lubricant is important. Its efficiency is ensured and any potential impurities are kept from damaging its quality by storing it in a dry, clean environment.
Additionally, be sure that there is no dirt or debris on the grease gun, grease nozzle, or relubrication tip before putting on the lubricant. The alternator may sustain damage from contaminants, which could impair its functionality.
It is imperative that you take these safety measures to shield your car’s alternator from damage. You can keep the alternator operating properly and extend its life by following the suggested lubricating procedures and keeping everything clean during the process.
How Long will a Noisy Alternator last?
According to research, a well-functioning alternator will last up to 7 seven years or approximately, 100,000-150,000 miles. (Source) However, this depends on a various of factors including brand, type of car, and the conditions in which the alternator is used.
It is hard to put a specific duration as this will depend on the cause, how bad the situation is, and your car. It may take months before you experience anything more than the grinding noise, or your car may just die on your in the middle of the highway. While an alternator is a small part of your car, it plays a crucial role.
Once you get an alert on your dashboard or hear the squeaky noise, you should start making plans to have it fixed. A faulty alternator may also damage your car battery and cause other severe damages.
If you cannot have the entire alternator fixed at the moment, get a mechanic to install new bearings. An alternator will cost you anywhere between $25 and $40. A mechanic will charge you between $500 and $700 to install a new one.
If you can replace the faulty bearings and then have the alternator changed during your regular maintenance visit, you will save yourself a few hundred dollars.
On How To Fix A Squeaky Alternator Bearing
A squeaky alternator always indicates a malfunction that needs your attention. Fortunately, it is easy to fix if you understand the problem and have the right tools for the job.
Once you identify where the problem is, follow the steps to help you understand how fix a squeaky alternator bearing. Some of them are easy to accomplish, while others may require a certain level of specialized skills.
Even if you don’t plan to fix the alternator problem yourself, it always good to know what is going on and the options you have at your disposal. With the right information, it becomes easier to make the best decisions for your car and pockets.
Meet Mike O’Connor, (a DIY enthusiast), living in Cincinnati, a city ranked as the noisiest in the USA.
As a work from home dad, I have a first hand experience of how noise can truly affect your well being.
Soundproofing isn’t something that should be taken as a hobby, it should be a skill that every homeowner should be equipped with.
Most of the work documented on this blog comes from purely first hand experience, and the products recommended work as indicated.