Know Your Trailer Hitch

I made a small mistake last week. Well, maybe it wasn’t so small. OK, it was huge. As in a ton.

A buddy of mine asked me if we could use my truck to tow home a new-to-him boat he just bought. It was a couple of hours away, but he’s a good friend, so I agreed. Besides, he said he’d pay for fuel and sealed it with the promise of beer when the trip was done.

What I should have had: a Class IV hitch like this one, rated for 10,000 pounds. Photo courtesy of Wikimedia Commons.
What I should have had: a Class IV hitch like this one, rated for 10,000 pounds. Photo courtesy of Wikimedia Commons.

“How much does it weigh?” I asked him.

He said 7,000 pounds. No problem. My truck is rated for 7,700 pounds and it has the tow package on it. We’re good to go. So we go get it and bring it home with no drama, minus the hangover from the beer.

It was when I got home that my heart started to race a bit.

Even though my truck has all the factory towing goodies, and a decent tow capacity rating, what it didn’t come with is a hitch that is rated for the truck’s full capacity. A decal on the electrical connector said it had a Class III hitch, which on my truck is rated for up to 5,000 pounds and 600 pounds of tongue weight with a weight-carrying hitch. Nearly every boat trailer on the planet uses a weight-carrying-hitch tongue.

What I needed was a Class IV hitch, which is rated for up to 10,000 pounds. The ironic thing is that the factory sticker on the back of my truck said, despite the hitch ratings, “Tow vehicle maximum trailer rating may be less.” I found it fascinating that they left out the part that it also could be more, which is just as serious a safety issue.

So, before you buy a used boat, be sure the truck and hitch you are using are up to the job. You might find that the boat you are considering requires you to upgrade your hitch — or your truck.

Understanding Gross Vehicle Weight Ratings

When shopping for a used boat, assuming you already have a tow vehicle, it’s important to know how much the boat you’re interested in weighs on its trailer, and what your truck is capable of pulling. If you buy more boat than your truck can haul, you’ll have to shop for a new tow vehicle, too. True, there are worse problems to have, but it can get expensive if you’re not careful.

Factory hitches usually have the class and tongue weight capacity written right on them.
Factory hitches usually have the class and tongue weight capacity written right on them.

Typically the gross trailer weight rating (GTWR)  is indicated on a plate on the trailer tongue. If it’s not there, you just need to know the boat’s weight, its cargo and passenger capacity, and the trailer weight. You also need to know the tongue weight. If those are less than the towing capacity of your truck and its hitch rating, you’re good to go.

It’s a good idea to have a buffer between your GTWR  and the vehicle’s towing capacity. I like to leave 1,500 pounds in excess. That way, you’re not asking everything of your truck each time you tow.

Your gross vehicle weight rating (GVWR) is listed on a sticker on the driver’s door. GVWR is the maximum weight allowable for the vehicle, and it includes the weight of the vehicle, plus the weight options, accessories, cargo, and passengers.  It also includes the tongue weight of the trailer you are towing, so to help ensure that you do not exceed your cargo or payload capacity, you must include the tongue weight in the GVWR.

Knowing and understanding the  GVWR  of your tow vehicle is important in safe towing because it tells you explicitly the maximum amount of passengers and cargo you can safely carry in your truck or SUV. GVWR is constant and does not change, regardless of what you tow. It’s engineered in when the vehicle is manufactured. And because you know that tongue weight must be included in the GVWR, you know how much weight capacity you need to have “left over” for when you hook up your trailer.

For example, if you have a 5,000-pound truck with a 6,200 pound GVWR, you can safely carry 1,200 pounds in the vehicle. If you are towing a trailer with a 300-pound tongue weight, the amount of passengers and gear you can carry decreases to 900 pounds.

Again, it’s usually a good idea to get a vehicle with a bit more capacity than what your currents needs are. But at the very least, be certain the towed load and tongue weight are within your vehicle’s capacity.

Another example: Let’s say you have a 5,000 pound boat and trailer. With a 6,700-pound towing capacity, a two-wheel-drive Toyota Tundra with the five-speed automatic transmission and 4.7-liter V-8 would be a good choice. Its capacity is a little bit more than what you need, and that’s just what you want. Tongue weight should be 7%  to at most 10% of overall trailer weight, which means a Class III hitch would be best. A Class III hitch is rated from 350 to 600 pounds of tongue weight, which, again, is a little more than what you need, and that’s just what you want.

Boat Towing Safety: Secure That Bow Eye

I once bought a used boat that nearly landed in the back of my pickup. Well, that’s a bit of an exaggeration, but that’s what it felt like when it happened. I had picked it up super cheap. I was going to take it home, give a good going-through, polish it up, ensure everything worked, and sell it for a profit.

On setups like this, it’s almost impossible to run the bow strap on top of the roller, and that’s a good thing.
On setups like this, it’s almost impossible to run the bow strap on top of the roller, and that’s a good thing.

Then a slow-moving truck pulled out in front of me.

When I jumped on the brakes, the boat rode up the bow roller on the trailer and nearly launched itself into the bed of the truck.

Why do we always have to learn lessons that way?

I had never really given it much thought before, but that day taught me how important it is to make sure the bow strap is secured under the roller, not over it. If it had been attached under the roller, the boat might have lurched forward a bit, but I wouldn’t have had to stop at a lake to float the boat off the trailer and resettle it onto the bunks. If it had been attached, I wouldn’t have to change my drawers when I got home, either.

On setups where the bow eye is above the roller, a fixed-length safety chain is a smart move.
On setups where the bow eye is above the roller, a fixed-length safety chain is a smart move.

On some boat and trailer combinations, you have to run the strap under the roller, but I’ve begun to notice on some boats that it’s an easy mistake to make to run the strap over the roller. I’ve seen some setups where you had to run the strap over the roller, but either the manufacturer or the owner were smart enough to add a fixed-length safety cable or chain that will keep the boat in place in a panic stop on the road.

So we’re clear, the lesson here is to make sure the bow is snug to the trailer bow stop and crank the bow strap tight and under the roller. While we’re at it, I should point out that this is why lots of boats have eyelets on the transom and straps to hold the back down to the trailer. In the end, I got the boat home safely, fixed it up nicely and sold it for not much more than I paid for it. The only thing I got out of that experience, really, was a little wisdom and a good story.

A Primer on Towing Safely

While towing, you can almost measure acceleration with a sundial, and you can forget about passing anything — especially a gas station. You can’t stop all that quickly, either, and turning takes up more room than some motorists are willing to give you. But you have to get your boat to the lake, right? Right, so we’ve put together a brief primer on towing safety that we hope will help keep you safe — boating season after boating season.

A tow vehicle, boat, and trailer are a trio of valuable moving parts. It pays to develop skills and habits to keep them -- and you -- safe.
A tow vehicle, boat, and trailer are a trio of valuable moving parts. It pays to develop skills and habits to keep them — and you — safe.
  • Before getting under way, slide the draw bar into the receiver and insert the pin in from the left. That way, if the cotter pin falls off, you have one to two degrees of road camber to help keep the pin in place.
  • If the draw bar has multiple holes, use the hole that brings the hitch ball closest to the rear axle of the tow vehicle, unless you have interference with an exterior-mounted spare tire. The inner-most position creates less leverage, which is safer and provides greater stability while towing.
  • If you don’t have a backup camera or a friend to help you back up to the coupler, try it this way: Back up in 4- to 6-foot intervals at first, to get your truck pointed in the right direction. As you get closer to the trailer, make the intervals shorter, periodically stopping and getting out to check your progress. Before long, you will have stutter-stepped the hitch ball into place under the coupler.
  • Once you’ve lowered the coupler onto the ball, lock it in place and raise the tongue jack to its highest position. Crisscross the safety chains under the coupler, connect them to the loops on the receiver, and plug in the wiring harness. Crisscrossing chains forms a “cradle” that will catch the coupler should it come off the hitch ball. If you have “S” hooks, put the “S” over the eyelets on the hitch to minimize the risk of them falling off. Your chains should be long enough to accommodate tight right- and left-hand turns without dragging the ground. If they hang too low, twist them to reduce their length. Have at least four to five inches of clearance.
  • If you have a hand wheel-style coupler, be sure it’s as tight as can be. If you have the throw-latch coupler, padlock it closed. Now check your turn signals and brake lights.
  • Because boat trailers are almost invariably wider than the tow vehicle, set your mirrors so you can see the trailer’s orientation within the lane you are using, yet still offer a glimpse into the flanking lanes.
  • In terms of actual driving technique, a good rule of thumb is that the trailer wheels generally follow the path of the rear wheels of the tow vehicle. As for backing a trailer, the relationship with the direction of the trailer and your steering wheel inputs are inverse. In other words, to get the trailer to go left, you steer to the right. You can’t read it in a magazine and get it. Like docking a boat, it just takes practice.

For more trailering tips and information, visit OnlineTowingGuide.com.