Cutless Bearings for Your Boat

Bearings! You know, the things that make your boat go.

Thanks to Leonardo Divinci, bearings have been around for hundreds of years, and are still going strong! Today, boat bearings last longer than ever before. They come in a variety of sizes so you can find one that fits your needs perfectly.

However, you have to be sure you’re getting the right type of cutless bearings, or you’ll just wind up wasting your money. When it comes to bearings, what ones are right for you, and how can you know? Read on to find out!

What’s New About Cutless Bearings?

Along with legal requirements for marine parts, boat enthusiasts are receiving a special request. The U.S. Coast Guard Administration is asking boaters to use only deep grooved bearings on certain occasions. Instead of deep grooves, they’d like boaters to embrace a cutless design.

Why Cutless?

Cutless bearings have “V” shaped channels called raceways that form when metallic balls roll against each other. These bearings are on sailboat hulls to reduce drag. There is a need for silicone lubricant in bearings also, as they are not watertight and allow water to flow freely through them.

Some types of cutless designs have removable raceways that can separate or attach with ease. Highly durable bearings can last for several years without replacement.

The difference between a deep groove and a cutless bearing will most likely confuse the average boater. However, both kinds serve an essential purpose onboard a vessel.

It’s common for boaters to use the wrong kind of bearing when installing their boat engine. This leads to quicker wear and tear instead of performance enhancement. It is important to choose the right bearing depending upon conditions so the performance of the boat engine will have the best life.

Types of Cutless Marine Parts

First, you have an internal cutless bearing. These are great for use in the lower end of the propeller shaft. It’s mounted inside the transom. Next, there are external bearings, used in the upper end of the propeller shaft.

There are also the thrust bearings, designed to support the propeller shaft and help minimize any force that would apply against it. This type is typically used for marine vessels that carry significant thrust from their engines. For example, a tanker ship or an aircraft carrier might use a thrust bearing.

The antitorque cutless bearing helps reduce the torque that can apply to a propeller shaft. This type is typically used for marine vessels as well that require a great deal of steering control such as tugboats or barges.

Mistakes to Avoid Finding a Marine Parts Source

If you are looking to buy a cutlass bearing, then there is a particular set of things that you will want to avoid. While it can be tempting to go for cheaper options, realize that if they’re not made from high-quality parts or materials then you have a higher chance of having problems in the future. Problems like needing replacements sooner rather than later.

Next, avoid bearings that aren’t sold by a large manufacturer in the United States. You’ll also want to avoid purchasing bearings that weren’t tested or are not certified.

While some manufacturers may be able to make their testing equipment, this does not mean you can trust the results. Sadly, oftentimes tests done by the supplier aren’t accurate. That’s why you’ll want to see the results of a third-party assessment.

It is also vital that you look at the bearings that you’re purchasing in terms of size, weight, and quality. If they look too light for their given size or if the material looks thin then chances are good that they will not last very long and may begin to fall apart before the job is done.

Buy Fully Assembled Cutless Rubber Bearing

Additionally, it’s important that you only purchase a cutlass bearing that’s fully assembled. While there are some instances where buying separately can be cheaper, this is not always the case and you are better off going for an already assembled option. This ensures that all bearings are properly seated and will work as they should.

Next, avoid purchasing bearings that have a large amount of corrosion or grinding marks on them. This is often caused by water damage. While it may not be too noticeable in the beginning, it will become more apparent over time. Avoid corroded parts at all costs!

You will also need to avoid damaged and modified bearings as this can cause you to have problems in the future. Added stresses on the bearings will cause them to fail much quicker than usual. It’s better to play it safe instead of risking something like this happening down the road.

If there are any manufacturer defects, then it’s better to return them instead of using them. While you may be able to get away with it once or twice, there is a chance that this will cause the bearings to fail sooner. The last thing you want is to be stuck out on the water, all thanks to faulty bearings.

If you’re having trouble finding a reputable supplier, try reading a few customer reviews. Online customer reviews are a great way to determine if you’ll be getting a quality product that arrives on time.

Materials Used in Bearings

Moving on, the key material used in bearings is polytetrafluoroethylene or PTFE. This is a type of fluorinated polymer which means that elements are combined to create the desired properties. You can click here to learn more about what PTFE is and how it works.

A notable fact about bearings is that they are hydrodynamic. This term means that the bearings are designed to operate in a liquid, specifically water in the case of boating.
The holes found on bearings are strategically placed to allow water to flow through freely without any obstructions and reduce the risk of cavitation.

Alternatively, they can be filled with oil or grease if desired, but it is not recommended because it can result in a reduction of thrust or cavitation. When you look at the flow of water through a cutless bearing, you will notice that it can be classified into two different types: laminar and turbulent.

In the case of laminar flow, the water flows relatively smoothly. While in turbulent flow, water is forced through the bearing much quicker and at lower pressure levels.

The inside body of bearings helps to eliminate drag and resistance by moving along with the propeller shaft. Additionally, it is fitted with large holes for water to flow through freely and reduce resistance even further.

Friction is reduced through the use of lubricated bearings that will allow for smooth operation as well as corrosion resistance. The hydrodynamic design of bearings helps reduce thrust. The design also prevents propeller wrap and increases efficiency due to its lower drag properties.

Additional Advantages of Bearings

Did you know cutlass bearings give you a much broader range of movement? They also make it easier to steer with precision, while not having to worry about wear or tear due to friction.

They are designed specifically as an upgrade over mechanical bearings. They provide less friction, increased efficiency, and corrosion resistance.
We mentioned earlier that bearings are an important element in reducing the effect of cavitation. However, what is cavitation exactly, and why should you avoid it?

Cavitation occurs when water vapor condenses into bubbles. This happens immediately behind a propeller and on its surface while it moves through the water. This results in very low pressure that can damage the propeller and also drastically lower its efficiency.

Did you know, the cutless bearing is the most vulnerable part of a boat? It is in essence a bearing at the aft end and in the stern tube where a propeller shaft mounts to a boat’s driveshaft.

The bearings can break when they are exposed to high and low levels of moisture and when they have too much going on. The result is that the driveshaft spins at an off-angle, so it will need to be replaced soon.

Disadvantages of Bearings

There are a few disadvantages to keep in mind as well when it comes to bearings for boats. For example, lubricated bearings will attract more dirt and debris. You must maintain them regularly so that they can last longer and continue operating at optimum levels.

Otherwise, they can experience corrosion and wear that is not only expensive to replace but also inconvenient as well. Another important thing you will want to consider with bearings for boats is the fact that they are typically more expensive than mechanical bearings with grease fittings. Weigh your options carefully before making a final decision.

If you need to replace them, you will want to consider how much they cost as well as whether or not you are looking for a permanent solution. For example, if your boat has a damaged propeller shaft, it may be more convenient and less expensive to obtain an internal cutless bearing instead of installing a new one altogether.

How to Service Bearings

Good news! You can service your boat bearings. However, with the addition of grease fittings or oil-filled holes, you will be able to extend their lifespan even further.
When it comes right down to it, maintaining a cutless bearing is not difficult. You may even be able to do so yourself!

One of the easiest ways in which you can check for wear and tear on your cutless bearings is by installing a vibration monitor. This device can help determine whether or not you need to service your bearings or replace them altogether.

Overhaul Your Bearings

A cutless bearing that requires maintenance should generally be overhauled at least twice a year so that it stays well lubricated and functioning as efficiently as possible.

The only difference between an overhauled and a new bearing is that it has been cleaned, inspected, and re-lubricated. Overhauled bearings are less expensive and if maintained correctly will last longer than new ones. It’s something to consider if you plan on using your boat a lot or very frequently.

Overhauled bearings will need to be properly greased. After you apply a reservoir of thick grease to one side of the bearing, roll it back and forth until all surfaces are thoroughly coated. Be sure not to apply too much grease or use a high-speed setting, and you should be fine.

Then, continue adding grease to the side of the bearing that is against the shaft. This will create a film so that additional leaks don’t occur over time. If needed, add oil until it begins running out of the other end which will indicate that it’s full.

Afterward, you can install it in your boat and see how well it works. If there are problems, then you will need to repeat the process until you get the results that you’re looking for. It may take a couple of tries before everything is working properly but just be patient!

Have the Best Marine Engine Parts

As you can see, cutless bearings are an integral part of a vessel. They play an essential role in helping a vessel cruise faster with minimal water resistance. The boat owner needs to know the difference between a deep groove and bearings, as well as when to use them.

After reading this article, what type of bearings do you think will work best for your boat? If you’re still unsure, reach out to a local boating supplier today for an expert opinion. You’ll be glad you did. For more great tips, read another article.