Wheel bearings connect the wheels to the axle, which make them crucial components of the wheel hub assembly. They minimize friction to help the wheels rotate smoothly.

Have your vehicle checked by a mechanic as soon as you notice unusual wheel noises. Even if the wheel bearings aren’t the culprit, it’s better to err on the side of caution and make sure that your wheels are in top condition.

Take note, however, that these unusual sounds do not always mean that your bearings are faulty. Cupped tires and other wheel hub-related issues may cause similar noises.

The auto trans clutched planetary gear sets…with bands on the outside of the planetary to switch the ratios…the clutch pack is in the center of it all…to uncouple the thing at will.

So in a sense, the one way clutch just prevents the carrier from spinning backwards, and when you pick up some speed, the carrier starts spinning because of the wheels, so then the one way clutch releases it’s grip and then the one way clutches’ inner race just spins around without doing anything else. So in other words, it just locks the carrier in place until the wheels get momentum, and then it releases since the tension is gone?

I watched a video on the AA80E from WeberAuto, and the guy went over the Lepelletier gear set and the Ravigneaux gearset. It’s a fairly in-depth video, he goes over the entire structure of it piece by piece. It’s an hour long video, but he shows what happens when gear shifts occur, and what clutch packs apply during shifting. By you explaining that the middle planet carrier wants to spin backwards when starting off in 1st gear, it suddenly rang a bell in my head as to why the one way clutch was there. I think I understand the AA80E fairly well, as it’s design is actually fairly simple. It really is quite a feat of engineering

one-way clutch mechanism

To prevent this from happening, make sure that your wheel bearings are in good condition. Watch out for the following symptoms that may indicate a faulty bearing.

Abnormal tire wear may be caused by other suspension issues, so it is best to let a mechanic rule out other possible parts that may be causing your tires to wear unevenly.

While bigger and wider tires can certainly make your vehicle look cooler, they might be too heavy for your OEM wheel bearings. The added load can cause them to wear and fail faster.

Alright, thank you! I understand the concept now. So it basically holds the carrier from turning the opposite direction, preventing a really hard shift from 1st to 2nd.

Both inner and outer races are held to their respective elements with the clutch between them. The outer race might be interference fit, inner race with a keyway for example. Only way the driven element can be tied to the ouput element…

EDIT: Ok, I rewatched a video on the subject and this guy is saying that the one way clutch mainly activates during acceleration. If so, that also confuses me as to how it is activated in only 1st gear.

Your anti-lock braking system (ABS) warning light may also turn on if you have a bad wheel bearing. This is because the ABS sensor or encoder ring of some vehicles is integrated into the wheel hub assembly.

Makes sense. On a roller one way clutch, the outer race is splined to the transmission case. I think that a sprag clutch also has splines on the outside of it, but I’m not sure where that splines up to. Maybe it splines to the clutch drum.

I guess what I was trying to figure out was just exactly what it was there for. In the AA80E, it has one one way sprag. Also, assuming that the AA80E only has 3 planetary gear sets, it would make sense for the middle ring gear/planet carrier to want to spin backwards under acceleration.

One waygearbox

For this transmission, from the calculated kinematics of that carrier, it only wants to spin in reverse while accelerating forward in first gear. From 2nd gear onward, that carrier turns in the forward direction

Also for cars with auto engine shutoff or hybrids, using a one way clutch rather than hydraulic actuation is one less load imposed on the engine/electric motor when it starts up

If you’re going down a steep hill and have manually selected first, the carrier is driven forward by the tires. But the b2 clutch is engaged to lock the carrier.

A one way clutch allows the stator of the torque converter to freewheel during low slip operation, making the torque converter act like a fluid coupling.

When getting custom wheels, be sure to take into account the load capacity and other specifications of your vehicle’s wheel bearings.

Driving with bad wheel bearings can put you and your passengers’ safety at risk⁠—it can cause your wheel and/or tire assembly to become loose.

As mentioned, driving with bad wheel bearings can put you and your passenger at risk. Thankfully, you don’t have to break the bank to get high-quality replacements. You can find exactly what you need at an unbeatable price at CarParts.com.

One thing we want to provide is a high-quality online shopping experience. With our website, you can find and order the perfect wheel bearing replacements with just a few clicks.

One way gearreplacement

Failing wheel bearings can make the steering wheel feel rough and cause excessive vibration when accelerating or cornering.

If you’re not equipped with adequate knowledge and tools to identify the problem, let a mechanic troubleshoot your vehicle for you.

Ok, I actually need a little bit of help here. I know how a one way sprag clutch works. But I think what I need to know is if the sprag clutch’s outer race is held stationary. I think what i would like to know is exactly what it does, I know it only allows rotation in one direction, but how is it used (like, how is it actuated to provide smoother shifts)? I think I know that the inner race is attached to the input shaft. I can’t find any videos that show exactly how it actuates or anything.

It wants to spin in reverse in first gear while under power. After you pick up some speed, around 10mph, and release the throttle, the engine drops to idle and the tires are driving the carrier forward. That’s when the one way clutch releases.

Driving over potholes and speed bumps can cause your wheel bearings to wear faster. Constantly bumping into tall curbs can also damage them. While you can’t exactly change the conditions of the roads you pass by, you can deliberatey drive slowly.

If the noises are different across varying road surfaces, there’s a good chance that the sound is being produced by your tires. However, if the sound remains the same, it’s likely caused by failed wheel bearings.

Before you try to wrap your head around this Aisin 8 speed, I would suggest that you study how the Ravigneaux gearset works. This is a 4 speed units from the 50s. After you study this, then study the Lepelletier gearset. Lepelletier figured that adding a reduction gear before the Ravigneaux results in a 6 speed. Once you understand the Lepelletier, you can study the AA80E. Aisin, amongst others, figured out that adding one more clutch results in an 8 speed

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication. Read our full disclaimer here.

These bearings are usually held together by a metal ring. Most modern vehicles have single wheel hub assemblies, which integrate the hubs and bearings. However, on some vehicles, these two parts are considered two separate components.

Another symptom that drivers may observe is looseness or excessive play on the steering wheel. This typically becomes more noticeable while driving over rough road surfaces.

The short answer is no. As mentioned, driving with a bad wheel bearing is dangerous. Severely worn bearings may cause the brake rotors to wobble, resulting in reduced brake performance.

One waySprag clutch

While wheel bearings are designed to last the life of your vehicle, they aren’t invincible. They can wear and fail due to a number of reasons, such as the following:

Ok, I think I understand now. So the transmission i looked at was a AA80E, and it’s one way clutch is only used to help make the shift from 1st to 2nd nice and smooth, but only manual mode. From what I can see, it only helps the B2 Brake in stopping the center planet carrier, and is used for nothing else other than that. In other words, it basically is a B2 Brake helper and it doesn’t do anything more than that. It also makes it so that the planet carrier can’t turn the opposite direction. The B2 brake also engages in first gear in low range. Nothing else changes when you put it into low gear. The only issue I think I’m having is now I’m questioning my assessment on how it works, since in the operation chart, it labels the One Way Clutch as a circle, not a triangle, which means it engages even in Drive. Here’s the Operation Chart.

Another way to check the source of the sound is to temporarily overinflate your tires. If the wheels produce the same sound while you drive, the noise is likely coming from your wheel bearings.

The reason we are discussing dirt bike clutches is because your original question references all these concepts…as it contains one of each example.

The exact price can vary depending on several factors, including your vehicle’s year, make, and model. In general, however, you can expect a wheel bearing replacement to cost anywhere between $10 and $660. If you own a luxury car, you can expect to spend a lot more as its parts tend to be more expensive.

Keep your trips safe and hassle-free by ensuring that all faulty bearings are replaced right away. Have a mechanic check your vehicle as soon as your vehicle exhibits any of the symptoms above. Replace faulty bearings if needed, so you can get back on the road in no time.

@chunkyazian gave you some excellent insights. It would help if you actually held a planetary gear set in your hand…and imagine what power inputs and torque loads would be trying to do with each component.

One wayroller clutch

One-way clutch types

You really do have to pay attention… there are a lot of clever things going on in there. I’m still amazed every time I have to look at some of those drawings etc…

It was designed this way before the age of fast electronic that can open and close the first gear clutch precisely. And you want to be able to disengage first gear while coasting because such low ratio provides in significant amount of engine braking if the clutch remain engaged, especially in a modem 8 speed.

Choose from a wide selection of competitively priced wheel bearings sourced from the leading brands in the industry. They passed stringent quality control tests, so you’re sure to get parts that are built to last.

In some cases, yes, custom wheels and tires can cause your wheel bearings to wear faster. This is because original equipment (OEM) bearings are designed to carry specific loads, which means they won’t be compatible with every single tire out there.

So, in other words, the one way clutches inner race, which is connected to a planet carrier, never actually stops spinning, (unless B2 is applied) it just absorbs the shock impact of the B1 brake applying? It basically just takes the shock of the B1 brake applying so that way the shift becomes less jerky?

Unusual sounds coming from the wheel are often the first sign that something may be wrong with the vehicle’s wheel bearings. Bad wheel bearings produce noises that are often described as growling, humming, or rumbling sounds. In some cases, these failing parts may also produce a high-pitched sound.

Whatever the cause may be, vehicle warning lights shouldn’t be ignored. Have your vehicle checked right away, so you can have the wheel bearings or any other faulty components replaced.

In an ideal scenario, wheel bearings can last up to approximately 85,000 to 100,000 miles. But remember that this is just an estimate. Several factors can affect the lifespan of your bearings, such as their quality and the way you drive your vehicle.

Then you can layer in why clutches and one way sprags are sprinkled where they are etc… A clutched, sprag’d, planetary is deceptively complex and very elegant in design.

Faulty wheel bearings can cause your vehicle to pull to one side as you apply the brakes. However, take note that it’s also possible to experience abnormal side pull due to faulty brake components as well. For instance, a defective caliper or a worn-out rotor may cause similar issues.

One waybearing how it works

Thats why those cutaway… exploded parts views are so helpful. Many items in the trans are not immediately understood conceptually just at a glance.

To start, fill out our vehicle selector to narrow down the catalog to compatible bearings. Then, use the search filters to find the products that match your preferred brand, price, etc. We have a round-the-clock customer service representative, so if you have questions, don’t hesitate to contact them via our toll-free hotlines.

You can have first gear braked by a one way clutch in parallel with a brake bands/multiplate clutch, where the one way clutch is used for normal forward drive. Engine brake in 1st and reverse are provided by the actuated brake.

Like other symptoms, steering difficulty may be caused by more than one faulty component. It’s best to take your vehicle to an auto repair shop for proper diagnosis.

In that chart that you shared, the 1-2 shift is achieved by engaging b1 and releasing b1. If you get the timing wrong at such low ratio, you’re going to feel it, which is bad for a transmission meant for the lexus flagship. Using a one way clutch for first, b1 can progressively take the load as the one way clutch releases naturally

Since the tire assembly may loosen, drivers could end up losing control of the vehicle. Needless to say, this situation could cause major accidents on the road.

Wheel bearing noises are typically in sync with the rotation of your tires. The sound may become noticeably louder as your vehicle accelerates. In some cases, the sound may also change depending on the direction of the steering wheel.

One way gearmechanism

Wheel bearings come with a seal that protects them from water, mud, and road salt. In some cases, however, these contaminants can get past the seal, contaminate the grease, and damage the bearings.

It’s easy to overlook this symptom—especially if you often drive with loud music on. But the moment you turn the radio off, these noises become noticeable from behind the wheel.

It is normal for tires to wear out because of prolonged use or unfavorable driving conditions. However, uneven tire wear may also be caused by faulty wheel hub components, such as loose bearings that may cause misalignment.

Now that @chunkyazian has given you the proper names of what I was simply calling a “planetary” gear set… You can type those names in a search and you will find all sorts of diagrams and better still animations of those gears in motion. There are tons of them to view.

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