There are many reasons why you might need to replace a trailer winch. The original winch may be too small for your boat, or it may have worn out. Some owners simply want to upgrade to a better, more efficient model. Regardless of the reason, the project itself is pretty straightforward.
Let us give you some simple steps to replace a trailer winch, and some tips to make sure it is done correctly the first time.
Selecting a Winch
It is important to select a replacement winch that is up to the task. If the winch is too small, you risk damage to your equipment or even injury to yourself. Although selecting a winch that is too large does not pose any specific risk, it is a waste of money.
If replacing a factory-installed winch on a trailer that was dealer matched to the boat, you can usually select a replacement with the same rating as the existing winch. If you are upgrading to accommodate a different boat, or if the previous winch was not performing as desired, make sure the new winch is rated properly.
Winches are rated based on their pulling capacity. This can range from 1,500 pounds on a smaller manual model to over 10,000 pounds on a larger electric model.
To determine the winch size needed, you will need to know the total maximum weight of your boat (weight of boat + passengers + gear + motor). The boat weight is available in the owner’s manual or the manufacturer’s website.
Once you know the total boat weight, there are two popular methods for determining the proper winch size:
Total weight divided by 1.5 = minimum winch rating. For example, for a boat that has a total weight of 3,000 pounds: 3,000 pounds / 1.5 = 2,000 pounds.
Total weight x 75% = minimum winch rating. For example, for a boat that has a total weight of 3,000 pounds: 3,000 pounds x 75% = 2,250 pound.
You will notice that option #2 offers a slightly higher minimum winch rating. While many manufacturers and retailers rely on option #1, it often fails to take into account the worst-case scenario: a heavy boat loaded to maximum capacity on a steep ramp.
Because it is unlikely you will encounter this situation (few boaters retrieve the boat with passengers and gear aboard, especially under poor conditions) most experts feel comfortable with this method. If you want that extra safety margin, option #2 will provide it, as well as peace of mind.
Check out the best trailer winches on the market today!
Once you have selected a winch, it is time to install it. As stated earlier, this process is pretty straightforward and should take no more than an hour.
- Penetrating oil or spray
- Properly sized wrench and socket drive
- Drill with appropriate bit
- Wire brush
- Small can of zinc paint or primer
Removing the Old Winch
Make sure the trailer is placed on a level surface with plenty of workspace around the tongue area.
Spray the existing bolts with penetrating oil to loosen any rust, corrosion, or debris. Let the oil sit for 10 to 15 minutes.
Remove the bolts and set them aside.
Lift on the winch and remove it from the trailer.
If your new winch is equipped with tow cable or strap, there is no need to remove this from the old winch. If it is not included, it is possible to reuse the cable or strap from the old winch. Here are the steps for removing it from the drum.
Pull the cable or strap out to its full length.
Remove the nut holding the cross bolt.
Remove the cross bolt.
Inspect the cable or strap for damage or unusual wear. If this is present do not reuse it, replacing with new equipment.
Prepping the Area
Chances are you will see corrosion or wear where the old winch was mounted. This is a good time to address this issue, which will prolong the life of the trailer and ensure the new winch is properly placed.
Remove any dirt, debris or corrosion with a wire brush
Wipe the area down with a rag
Apply rust-resistant primer or zinc paint. Zinc is preferred for saltwater use.
Allow the primer or paint to dry.
Installing the New Winch
Check to see whether the new winch mounting holes line up with those used to mount the old winch. Most winches use a standard mounting pattern, but if this is not the case, you will need to install a mounting bracket or drill new holes.
If the mounting bracket is needed, install it now as per manufacturer instructions.
If you need to drill new holes, use the template provided.
Center the winch on trailer arm. (Tip: Measure and mark the centerline of the winch base plate and trailer arm. Line up both marks.)
Insert bolts and hand tighten them.
Tighten the bolts in a crisscross pattern, ensuring the winch does not move off the centerline
If the cable or strap needs to be installed, insert it into the drum.
Insert the cross bolt and attach the nut
Apply slight tension to the cable or strap and crank it onto the drum
Note: An electric winch will require the installation of an electrical supply. Follow the manufacturer’s instructions when completing this task.