To measure for a drop hitch, you need to take into account two important measurements: the hitch height, and the coupler height. Once you get these two measurements, the proper drop or rise for your hitch can be easily determined by calculating the difference between them.
It’s a simple process that will not take you more than ten minutes or so to figure out, and you can take the measurements with simple tools like a tape measure.
Before we get into the details on the measurement and calculation of a drop hitch, let’s take a look first at an equally important question: why will you need to account for the trailer hitch rise or drop?
Why Do You Need To Measure for Trailer Hitch Rise and Drop?
So why will you need to go to the trouble of measuring for the trailer hitch rise or drop? Can’t you just simply attach your trailer to your ball mount, load it up with your cargo and drive away to wherever you need to go? Well if you’re lucky enough to have a trailer match perfectly with the height of your trailer hitch, then you probably do not need to go through all these extra steps.
But the reality is, there are too many types of vehicles and trailer hitch configurations on the market. As a result, you cannot really expect a trailer to be able to perfectly match just about any vehicle and mount receiver, including whatever tow vehicle and towing accessories you happen to be using at the moment.
Now since your trailer hitch rise and drop may not exactly match each other, then you will need to account for the difference. That’s where your drop hitch measurement comes in, so you can compensate with the right drop hitch.
Why Having a Drop Hitch is Important for Towing
The main reason that you will need a drop hitch is a simple yet important one – it’s to keep the trailer level while it is attached to your tow vehicle. Having a level trailer setup is extremely important when towing. A trailer setup that is perfectly level and straight is a setup that is a lot safer to drive, both for you and the other vehicles on the road.
When we say that a trailer is as level as possible, it means that the trailer is perfectly horizontal as it sits on the road, with the trailer hitch attached to the tow vehicle’s mount. A trailer that is out of level, on the other hand, is a trailer whose front end will tilt upward or downward when the trailer is linked to your car or truck.
Potential Issues That Can Come Up When The Trailer Is Not Level:
A trailer that’s out of level is a problem on the road, both for you, your passengers, and possibly the other vehicles you meet on the road. It’s a setup that will not handle well, and it could lead to dangerous situations where the trailer sways and wobbles while you’re driving at speed.
A trailer that dips downward puts more weight on the rear axle of the tow vehicle, and this situation will shift some of the weight off of the front wheels of your car or truck. The result is a weaker response to your steering, which can be all it takes to cause you to lose control of your vehicle.
Aside from the safety factor, there is also the comfort factor as well. A trailer that does not sit level can be noisier, not to mention harder to handle. The longer you drive around a trailer that’s out of level, the bigger the possibility that it can cost you in the long run, too.
A trailer that dips up or down can cause uneven wear on the tires of the trailer and the tow vehicle. An imbalanced trailer will also cause more strain on the tow vehicle, the towing accessories and the trailer as well.
Finally, a tow trailer that dips upwards or downwards can have its cargo shift around while in transit, which can further worsen the balance issues with your trailer setup.
What Drop Hitches Help With:
To have a level trailer, you might need to have a drop hitch equipped on your tow vehicle. The drop hitch gives you a way to change the height of the trailer hitch receiver or the tow ball mount, depending on the design of your drop hitch. With this, you can match the height of the trailer coupler with the height that your tow ball sits at, so you can have a trailer that sits nice and level.
Many drop hitch receivers will fit into a standard receiver opening, and some drop hitches may be built into the tow bar as well. Depending on the design, a drop hitch can give you anywhere between 2 inches to more than 12 inches of fixed or adjustable vertical height, which determines the range of heights you can adjust for.
Fixed drop hitches will give you a certain amount of drop or rise, which will hopefully match the right vertical adjustment to keep your trailer level. If you plan to tow different trailers, which may be of different heights, then you may need to consider having an adjustable drop hitch receiver.
These receivers allow you to pick from several drop heights without having to change out your drop hitch, and this can be handy for adjusting for the different heights when you switch between different trailers.
What Do You Need to Measure For A Drop Hitch?
First, you need both your trailer and your tow vehicle parked on level ground. Ideally, you want your tow vehicle and your trailer loaded up with cargo or weight similar to what it will carry for the trip, so you can get a more accurate measurement. You will also need the trailer to be sitting level, so you may also need a trailer jack or trailer kickstand to prop up the trailer tongue to the right height.
Then, you will need a measuring tool. A tape measure is the best tool to have for these kinds of measurements, but a ruler or a square should work just as well.
How Do You Measure for Rise and Drop for Your Ball Mount or Drop Hitch?
To measure for the rise and drop for your drop hitch or ball mount, you will need two measurements: the hitch height and the coupler height. The hitch height is measured for the tow vehicle, while the coupler height is measured for the trailer.
If you have different trailers that you plan to tow with one tow vehicle, then it’s a good idea to do these measurements all at once and note it down somewhere for reference.
First, let’s look for the hitch height for your tow vehicle. The hitch height is measured from the pavement to the inside wall at the top of the receiver opening, so you need to have a hitch already installed for you to be able to measure this. Do take note that the hitch height is measured from the inside the receiver opening, so the thickness of the receiver tube is not a factor here.
The coupler height, on the other hand, is measured from the pavement to the bottom surface of the coupler. This measurement should be read from the coupler itself, and not on the trailer tongue. Since the measurement is read off of the bottom of the coupler, the thickness of the coupler is not a factor here either.
Once you have the two measurements, it’s time to compare them. If your hitch height is higher than your coupler height, then your trailer coupler is too low for your hitch receiver. In this case, you will need a drop hitch or a tow ball mount with a drop. The drop measurement is the difference between the hitch height and the coupler height.
On the other hand, if your coupler height is higher than your hitch height, then your trailer couple is too high for your hitch receiver. To have a balanced trailer setup in this case, then you will need a rise hitch or a tow ball mount with a rise. Just like above, the rise distance is the difference between the coupler height and the inch height.
An Example Of How It Works:
For example, if you have a hitch height of 15 inches and a coupler height of 12 inches, then you will need to use a drop hitch with a 3 inch drop. A tow ball mount with a 3 inch will work just as well to set your trailer to level. So will an adjustable drop hitch that’s been set to be 3 inches lower than the hitch receiver.
On the other hand, say you have a coupler height of 15 inches, but your car’s hitch height is only 10 inches high. To keep your trailer level, you will need a rise hitch that has a rise of 15 minus 10 inches, or a 5 inch rise. Again, a tow ball mount or an adjustable drop hitch with a 5 inch rise will work just as well in this case.
How Do You Measure the Rise and Drop On Your Hitch or Tow Ball Mount?
Once you know the rise or drop that you need, then it’s time to get a tow ball mount or drop hitch with the right drop or rise distance. Most of the time, you can tell that you have the accessory with the right rise or drop simply by looking at the label or the markings on the drop hitch or tow ball mount itself. If you have to verify, though, then you can easily do so by making a few simple measurements on the attachment.
To measure the drop of a tow ball mount, you simply measure the distance from the top surface of the shank to the top of the tow ball platform. Measuring the rise is similar – again, you look at the distance from the top of the shank to the top of the ball platform.
Compare the drop or rise of the tow ball mount that you just measured with the difference between the coupler height and the hitch height. If you have a match, then that tow ball mount is the one you need to have a level trailer – assuming, of course, that the tow ball is of standard height.
To measure the drop of a drop hitch, then you will just need to follow similar steps. To get the drop distance, simply measure the distance from the top of the shank (the part that goes into your hitch receiver) to the top of the drop hitch’s receiver opening. Getting the rise distance is the same – you just measure from the top of the rise hitch’s receiver opening down to the top of the shaft.
Again, compare the drop or rise distance to the calculated difference in height between your hitch receiver and coupler. If it matches with the distance of your drop hitch, then that attachment will help you get a level trailer setup.
Sometimes, you get a height difference that does not exactly match the drop hitches or tow ball mounts you have available. In this case, you may have to settle for using the one closest in fit.
Just to give you an example, say that the difference between your hitch height and couple height comes down to 4 1/2 inches. If you have, say, three drop hitches that have 2, 4 and 6 inch drops, then the 4 inch drop accessory will be your best choice at the moment, even with the half-inch difference.
A Few Extra Tips:
So you have figured out the drop or rise that you need. How do you get your drop hitch to match the drop or rise distance? First, keep in mind that you can usually flip a tow ball mount or a drop hitch.
That way, you can use the same accessory to give you a rise instead of a drop, or the other way around. Adjustable tow ball mounts and drop hitches can also be flipped, so you have as much versatility as you need to adjust for multiple trailers.