How to Choose a High-Low Adapter

How to Choose a Tow Bar Adapter for Flat Towing Behind an RV

Flat-towed vehicle hooked up to RV

To flat tow your vehicle behind your RV, you will most likely require a tow bar adapter to raise or lower the height of the tow bar to the "Safe Zone". The "Safe Zone" for a motor-home-mounted tow bar ranges from 3" above level to 3" below level. Car-mounted tow bars must be completely level. A tow bar adapter will provide the necessary rise or drop to get into the "Safe Zone".

How to Measure for a Tow Bar Adapter

Safe Zone illustration

Step 1: Measure the hitch height

With the RV parked on level ground, measure from the ground up to the center of the trailer hitch receiver opening as shown.

Measuring trailer hitch height

Step 2: Measure the tab or base plate height

Park the dinghy or toad on level ground and measure as shown from the ground up to the center point of the tabs/base plates where the tow bar attaches.

Measure Jeep base plate Measure Ford Focus base plate

Step 3: Subtract to find the difference

If the trailer hitch on the RV is higher, then the difference in the measurements is the amount of drop you need. And if the tabs/base plates are higher, the difference is the amount of rise you need.

Step 4: Select an adapter with the rise/drop needed to put your rig into the "Safe Zone"

Tow Bar adapters are measured from the center of the shank that fits in the receiver to the center of the receiver opening at the other end of the adapter. Once you determine the right rise or drop needed you can select the right adapter!

High-low adapter rise and drop illustration
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Consider an Anti-Rattle Device

Anti-rattle device for flat towing

To get the best performance out of your towing setup, consider using an anti-rattle device. These devices help prevent movement of a ballmount or other hitch-mounted accessory in a receiver hitch. Not only does an anti-rattle device keep hitch-mounted accessories quiet, it will help your towed vehicle track better behind your RV by preventing looseness in your towing setup. Be sure when shopping for an anti-rattle device that it is made for towing use. Some anti-rattle devices are designed only for use with hitch-mounted accessories like bike racks.

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Read more about anti-rattle devices

Written by: Michael H.

Last updated: 10/23/18

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