The propeller on your boat is one of the most important parts to consider. It can determine how well your vessel will run, and it's also responsible for keeping you safe when out on the water. To make sure that everything works as it should, it's important to do routine inspections and in some cases, change out the propellers all together. Luckily this process is fairly simple—just follow these simple steps!
Tools you’ll need
- Safety glasses
- Propeller removal tool
- Hammer
- Wrench and pliers for removing the nut (if you don't have a special wrench, use the hammer to tap it off)
- Screwdriver for removing the cotter pin from the propeller shaft (if you don't have a screwdriver, use a piece of wire)
Materials
- You'll need to gather the following materials to change your boat propeller:
- Propeller
- Thrust washer (if applicable)
- Waterproof grease
- Propeller nut
- Cotter pin
- Propeller hub (if applicable)
- Clean rag/towels
- Propeller nut wrench (socket wrench and ratchet, if you have them)
Remove the Cotter Pin
Once you have the cotter pin pulled, you can remove the propeller. Depending on your boat and its propeller, there are several different ways to do this. The easiest way is to use a cotter pin puller (a tool that looks like a U-shaped metal clamp). However, if you don't have one or don't want to buy one then your options are limited: You can tap the pin out with a hammer and chisel, pry it out with some pliers (needle nose or regular), or even just leave it in place if your new propeller has a reverse threading on it so that when you put it back together everything will be fine anyway!
Unscrew the Propeller Nut
Once you have the propeller removed, you'll see a white nut with serrations on the end. This is what holds the propeller in place and requires loosening before removal.
If you have a wrench or socket wrench, use it to loosen the nut. If not, try using a ratchet instead.
Once you've removed this nut, put it somewhere safe so that it won't get lost or damaged during installation of your new propeller!
Remove the Nut and Washer
The first step to changing your boat propeller is to remove the nut and washer from the end of your motor shaft. You'll need a wrench to remove the nut, and a screwdriver to pry out the washer.
The next part of this step involves removing any other parts that are in your way, like gaskets or seals. Make sure you keep track of these things so that you don't misplace them when it's time for reassembly!
Clean the propeller hub.
Now that you have the new propeller in place, it's time to clean the hub. Start by using a clean rag or paper towel and cleaning off any dirt or debris from inside of the boat's hull. This is important because if there was any dirt or debris in this area, it could potentially scratch your new propeller when you install it.
Next, take another clean rag and wipe down all of the fasteners on both sides of your boat's transmission shaft: nut, washer and cotter pin (if applicable). This will help prevent corrosion from occurring on these parts over time—and also make sure they don't get stuck during installation!
Remove the Thrust Washer
To remove the thrust washer, you will need to use a screwdriver or hex wrench and gently pry it off. Be careful not to damage the propeller hub or your hand. If this is impossible, use a hammer and chisel to break off one side of the thrust washer. This will expose its internal prongs, which can then be removed with pliers or vice grips.
Once all three pieces of the old thrust washer are removed, install your new one by reversing these steps in order.

Install new thrust washers onto propeller shafts (with prongs facing down)
Add Waterproof Grease
With the propeller shaft out of the water, you can change your propeller nut and washer. You will also want to replace the thrust washer at this time. Apply a little waterproof grease to each of these three items before installing them into place.
Once all three are back on your boat, replace the cotter pin with a new one and tighten it down until there is no more play in the pin itself or in its hole in your prop nut and washer assembly.
Replace the Propeller (Reversal of the Removal Procedure)
Make sure the propeller is centered and not twisted.
Make sure there are no cracks or other damage to the propeller or hub flange (the part of the boat engine that holds the propeller on).
Tighten down any bolts that were loose; then tighten them an additional half turn if they were only slightly loose before tightening them all off again—we want this thing on there tight!
Tighten the Nut
Once you've readied the new propeller, you'll need to install it onto your boat's shaft. To do this, start by tightening down the nut on the back of your boat's engine until it is snug. You want to make sure that you don't over tighten this nut as this could cause damage to your boat's engine or drive shaft. If you are using a torque wrench for this step (this is highly recommended), be sure to set it to the correct torque. Otherwise, just use your hands and tighten until no more play is present in either direction (your hand should be able to spin freely around the propeller).
Key takeaways
The propeller is an important part of your boat, so it’s important to take the time to change it properly. There are many benefits to doing this project yourself, including saving money and gaining a sense of accomplishment from completing such a big task. With these instructions, you should be able to change your propeller in no time!