Flat Tow Baseplates and Tow Bars, Explained

By Jeff McDonough, Founder of TowPro Academy, 10+ years and 250,000+ miles of towing experience.

Short answer: A flat tow setup connects your motorhome to your toad through three hard parts: the hitch receiver on the motorhome, the tow bar, and a baseplate bolted to the front of the towed vehicle. The baseplate is made for your exact vehicle. The tow bar is chosen by style and weight rating. The two have to match each other, the bar has to ride close to level, and every part in the chain has to be rated for what the toad really weighs. None of that matters until your owner’s manual says the vehicle can be flat towed in the first place.

Most of what you’ll find on this topic is a product page. This guide explains how the parts work together and what to check, so you can shop and hook up with your eyes open. When in doubt, the instructions for your specific baseplate and tow bar win over anything here.

Start with the owner’s manual, not the parts catalog

A baseplate listing for your car does not mean the car can be flat towed. Blue Ox says it plainly on its baseplate finder: read your towed vehicle’s owner’s manual and check with your dealer to find out whether the vehicle is flat towable and what the correct towing procedure is. Roadmaster’s tow bar manual says the same thing in its own words. Some vehicles need a transmission lube pump, an axle or driveline disconnect, or free-wheeling hubs before they can be towed, and skipping that step can wreck the transmission.

If you haven’t confirmed that yet, start with Can My Car Be Flat Towed? For examples of how the answer can change by model year, see our guides on the Jeep Wrangler and Ford Bronco and the Honda CR-V and Chevy Equinox.

A dead battery after a travel day is a separate setup issue; see flat towing battery drain.

Once the parts are installed, run every hookup from a written list; ours is a free printable flat towing checklist.

The parts of the connection

Think of flat towing as a chain. Every link has its own job and its own rating:

• Hitch receiver on the back of the motorhome. It has a class and weight rating, usually printed on it.
• Drop or rise receiver (if needed). It moves the connection point up or down so the tow bar rides close to level.
• Tow bar. The arms that link the motorhome to the toad. It has its own weight rating.
• Baseplate. The vehicle-specific bracket on the front of the toad that the tow bar pins to.
• Safety cables, lighting and a supplemental braking system with a breakaway. These aren’t part of the mechanical link, but you need them on every tow. See our guide to supplemental brakes for flat towing.

The 2019 MotorHome Guide to Dinghy Towing (hosted by Roadmaster) sums it up: hitch receivers, tow bars and baseplates all have to be in good working order, rated for the weight of the dinghy vehicle, and designed for the specific application.

Baseplates: why they’re vehicle-specific

Blue Ox describes a baseplate as a semi-permanent bracket installed on the front of a vehicle where a tow bar can be connected, engineered to spread the stress of towing and braking more evenly. That’s why there’s no universal baseplate. Every vehicle has different frame rails, bumper beams, crash structures and fascia shapes, so the bracket is designed around that specific body.

The dinghy towing guide calls the baseplate “perhaps the most critical component.” Hitch receivers and tow bars are built to fit many vehicles, but most dinghy vehicles need a specific baseplate based on brand, model and year. The same guide notes that some installs mean temporarily removing the bumper cover, minor drilling, or trimming the grille, air dam or belly pan, as described in the baseplate maker’s fitment instructions.

What to check when choosing a baseplate

• Exact fit. Look it up by year, make and model in the maker’s fit guide, and pay attention to trim and option notes. If your exact vehicle isn’t listed, don’t assume a similar model’s part will fit.
• Tow bar compatibility. Blue Ox tells buyers to make sure the tow bar is compatible with the baseplate’s tab width. Baseplate and tow bar brands don’t always connect directly, so confirm the connection with the maker before you buy.
• Rating. Roadmaster’s tow bar manual says the hitch receiver, baseplate, safety cables and all other towing equipment must be rated for at least the weight of the towed vehicle and everything in it.
• Removable tabs. Many baseplates have tabs or arms that come off when you’re not towing, which keeps the front of the car looking normal and avoids a shin-catcher in the driveway.

DIY or pro install?

Blue Ox lists its baseplates as requiring no welding. The dinghy guide notes that installing a baseplate doesn’t take welding or special tools but “can be rather involved,” and recommends hiring a professional if you have any doubts. My rule: if the instructions have you pulling the bumper cover and drilling into structure and you’ve never done it, pay someone who has. This bracket carries your car down the highway. Read the instructions before you buy so you know what the job involves.

Tow bar types

The dinghy towing guide sorts tow bars into two basic styles, A-frame and self-aligning, and splits self-aligning bars into motorhome-mounted (coach-mounted) and car-mounted (dinghy-mounted) versions.

Self-aligning bars are also sold in different weight classes. The guide mentions Class III (5,000-pound) and Class IV (10,000-pound) models, and higher-rated bars are available. Pick by the real weight you’ll tow, not by what sounds tough.

How a self-aligning hookup goes

The guide describes it in four steps: get the toad near the center of the bar and within its length, pin the arms to the baseplate with pins and clips, connect the safety cables and the electrical cord, then drive the motorhome forward slowly (or roll the toad back) until the arms lock. For the full hookup order, including the toad’s own prep from the manual, see How to Flat Tow a Car Behind a Motorhome.

Keep the tow bar level: the “Safe Zone”

This is the setup mistake I see most. A motorhome’s receiver is usually higher than the toad’s baseplate. The dinghy guide says motorhome ride height “rarely matches” the dinghy, so you often need a drop receiver to let the bar ride level.

Roadmaster calls this the “Safe Zone”. For motorhome-mounted tow bars, that means no more than three inches above or below level. Car-mounted bars have to be approximately level. Roadmaster’s manual warns that an out-of-level bar causes significant wear on the tow bar, the baseplate, and the towed vehicle’s suspension and frame, and can eventually make the towing system fail. Towing outside the Safe Zone also voids Roadmaster’s warranty. Other tow bar makers publish their own limits, so check the manual for your bar.

How to measure

1. Hook up the motorhome and toad on level ground.
2. Measure from the center of the motorhome’s hitch receiver opening to the ground.
3. Measure from the center of one tow bar base pin (where the bar meets the baseplate) to the ground.
4. Compare. The difference is how far out of level you are. More than three inches on a motorhome-mounted bar means you need a drop or rise receiver to bring it into range.

Two cautions. First, the drop receiver is a link in the chain too, with its own rating, and it has to cover the toad’s weight. Second, Roadmaster warns that receiver extensions make the system swing through a much bigger arc and put extra strain on the bar, baseplate and frame. If you have one, be strict about staying within three inches of level. The dinghy guide adds that receivers should be bolted in place (not welded) using the receiver maker’s hardware and instructions.

Ratings: the weakest link sets your limit

Every part has a number: the motorhome’s towing capacity and GCWR, the hitch receiver, any drop receiver, the tow bar, the baseplate and the safety cables. Your real limit is the lowest of them. Buying a heavier-duty tow bar doesn’t raise the receiver’s rating. Upgrading the receiver doesn’t raise what the chassis maker allows. The dinghy guide says an upgraded hitch receiver can’t go past the weight limit set by the chassis manufacturer.

Use the toad’s real loaded weight. Roadmaster’s manuals say the towed vehicle and all its contents can’t exceed the tow bar’s rating. If the back seat is full of camp chairs and a cooler, that counts. For how the combination numbers work, see What Is GCWR? For receiver classes and what each one means, see Trailer Hitch Classes Explained.

Safety cables, pins and the things that let go

• Pins and clips. Roadmaster’s manual is blunt: unless the tow bar is secured to both vehicles with all the right pins (or locking pins), the toad will detach. Check every one, every time.
• Cross the cables. Run the safety cables frame to frame and cross them under the hitch receiver. If the bar ever separates, crossed cables help keep it from dropping and digging into the road.
• Right length. Leave enough slack for sharp turns, but not so much that the cables drag or snag. A receiver extension may mean you need longer cables.
• Use the right hardware. Roadmaster says not to swap its quick links for carabiners. Replace any cable that’s frayed, pinched or damaged before you tow again.
• Know your law. Roadmaster notes that safety cables are required by law in many states. Check the rules wherever you’ll drive, and see our towing laws by state overview.

Care and wear points

A tow bar is precision equipment that rides behind your motorhome tires through rain, road salt and grit. Roadmaster’s manual for its Liberty tow bar lists the habits that keep it working:

• Inspect before every tow. Check the mounts, brackets, fasteners, bolts, wiring and safety cables.
• Check the baseplate on a schedule. Roadmaster says to check it every 3,000 miles for fractures, cracks or other visible damage, check bolt torque against the installation instructions, and not to tow if the baseplate is damaged.
• Clean, then lubricate. Clean the arms first, then use the lubricant the maker specifies. Lubricant put on over road film can keep the arms from sliding properly.
• Watch the exhaust. When storing the bar on the motorhome, rotate the arms away from the exhaust. Heat can warp the bushings, and then the arms won’t slide.
• Before long storage, clean and lubricate the bar, then cover it.
• Stuck pins on a hill? If the toad’s weight is binding the pins, let it ease forward just enough to take the tension off, set its brake, then release.

Your bar may be a different brand or model, so follow its manual for intervals and products. The point stays the same: the hardware wears, and catching it in the driveway is a lot cheaper than finding out on the interstate.

Don’t back up with the toad attached

Tow bars are built to pull, not push. Blue Ox warns that backing up with a tow bar connected can jackknife the towed vehicle, bend the bar or jam it in a locked position, and push force into the toad’s frame. The dinghy guide adds that most tow bar makers won’t warranty damage caused by backing. Plan fuel stops and campsites so you can pull through, and if you get boxed in, unhook, reposition and hook back up.

FAQ

Do I need a baseplate to flat tow?

Yes. The tow bar needs a strong, engineered connection point on the towed vehicle. That’s the baseplate. Blue Ox warns that trying to flat tow without one risks damage to the towed vehicle and danger to other drivers.

Can I move my baseplate to my next car?

Generally no. Baseplates are built for a specific vehicle. Your tow bar may carry over if its rating and connection type suit the new toad, but plan on a new baseplate for the new vehicle.

Motorhome-mounted or car-mounted tow bar?

The dinghy towing guide calls motorhome-mounted self-aligning bars the most desirable, since they’re less likely to be damaged when not in use and one person can hook up. Car-mounted bars stay on the toad and have to ride approximately level. Choose based on your rig, your rating needs and where you’ll store the bar.

How level does the tow bar need to be?

For motorhome-mounted bars, Roadmaster uses a three-inch limit above or below level, and other makers publish their own figure. Measure on level ground from the receiver center and from a base pin center to the ground. If the difference is bigger, add a properly rated drop or rise receiver. Always follow your own tow bar’s instructions.

Does a bigger tow bar let me tow a heavier car?

No. A tow bar’s rating doesn’t raise the hitch receiver, the baseplate, the cables or the motorhome’s limits. The lowest rating in the chain is your limit. See Flat Tow vs Tow Dolly vs Trailer if your toad is too heavy, or isn’t approved, for four-down towing.

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