Extend, or Build an Adjustable Length Trailer Tongue?

Is there an easy way to build an adjustable length trailer tongue?  This may seem like an odd question, yet it has come up many times.  While the question seems simple and direct, there are actually a lot of pieces to give a good answer.  If you are ready, we can dive into a few variations as answers to this question.

First, we should define the question.  In the phrase “adjustable length trailer tongue” there is a need for making the trailer tongue longer, but how much longer?  Or How much shorter?  We will talk about making a short extension, then we will talk about how to extend a trailer tongue – well, long.  To be complete, we will discuss the full adjustable length trailer tongue.

Second, what trailer are we talking about?  For an existing trailer?  Or for a trailer you want to build?  The approach is quite different.

Third, how Permanent or Temporary will we extend or shorten the trailer tongue?  That makes a big difference too.

This short article will give just a few thought provoking ideas about how to extend a trailer tongue.  Some ideas are adjustable, some are permanent.  We will not go into a lot of detail with any of the concepts, or this will become a book instead of an article.

I must also point out that there is some risk with these, so it is really important to understand the limitations of each the design concept.  If you use one of the ideas, please make sure you know the trailer is strong enough to handle it – and, more important, where using these concepts is a mistake.

Where Do We Start?

For the sake of brevity, we will look only at a few specific cases.  In the three points above, there are 12 total variations possible ( 3 * 2 * 2 ).  We will look only at these 3 concepts:

1. Simple, permanent, short, tongue extension on an existing trailer.
2. Adjustable length, permanent, change for a new trailer build.
3. Temporary, long, tongue extension for an existing trailer.

Obviously, with all of these, you can take the concepts and mutate them to work different – longer or shorter, built-in to a new trailer or retrofitted on an existing trailer, etc..  A fully adjustable length trailer tongue, or something permanent.  “Thought Starting” is exactly the point of this article.  We wish you the best as you transform these ideas into your own !!

Universal Things We Must Get Right

Here are a few things with respect to strength we must get right.  Keep these in mind if you extend a trailer tongue:

1. The additions, whatever they are, must be stronger than the tongue we are replacing.  Far too many trailer tongues are weak, so we certainly don’t want to create something weaker.  Making an adjustable length trailer tongue requires materials and structure to support likely higher loads.
2. If you cut an existing beam, add sufficient material in the area so the finished new tongue is at least as strong (hopefully stronger) than the original.  It is not enough to cut a tube, then add in another section.  We must also add strengthening pieces to compensate for welding around the tube.  See this other article about weld distortion and weakening.
3. Make sure to strengthen the area where the tongue connects to the trailer frame.  A longer tongue is a longer lever that can create even more stress, so strengthen the area where the tongue connects to the trailer frame.

Extend An Existing Trailer Tongue

We will start with item number 1 from the list above:  Make a simple, permanent, short, tongue extension on an existing trailer.

Obviously, there are too many different types and configurations of trailers for us to really do this topic justice.  And, so much of the “How To Do It” will depend on the type of existing trailer tongue.  We will show an example, then let you configure your own details.

This idea will extend a trailer tongue, but it is not an adjustable length trailer tongue.

Single, Straight, Tongue Tube

If the existing tongue is a single center beam, often the best approach is to simply cut the tongue, then add in another section of tongue to make it the right length.

1. Cut the tongue tube at a place closer to the hitch than to the trailer frame.  (This is an area of naturally lower stress.)
   One of the highest stress areas of most trailers is where the tongue connects to the trailer frame.  Stress in the tongue decreases as we then move along the tongue tube toward the hitch, so we should make the extension there.
   
2. Add in another section of matching material – same size, and same thickness.  Obviously, give care for straightness, chamfers for weld fill, robust welding, etc..  Weld, then grind the welds flat for the next step.
   
3. Add strengthening patch plates over the outside of the new welds.  The taper shape helps distribute the added stress and weld weakening that naturally occurs when splicing a beam.
   
4. Assess the area where the tongue connects to the trailer frame.  When we extend a trailer tongue, we are adding to the lever that can bend or break the tongue, so usually we need to strengthen that area too.  One possibility is in the image.
   

I will leave the rest up to you.  Finish it up, and enjoy the longer tongue.

A-Frame Tongue

Admittedly, the A-Frame tongue and hitch do make it more difficult to extend a trailer tongue.  In most cases, it is best to also convert the tongue from an A-Frame to a Straight Tongue in the process.

There are a number of ways to make the change, but I recommend that you do not cut off the A-Frame.  Use the “A” portions to support the new, longer straight tongue tube.  You can notch the A-Frame for the new straight tongue tube, which is probably the best approach.  Other options exist, but the final result will be a single tube coming from the trailer frame through the A point, then extending out from there.

The difficulty with this approach comes in making sure it is all stronger than the existing tongue.

An Adjustable Length Trailer Tongue

There are probably a dozen ways to implement this concept, but we will look at one example.  This one, to build into a new trailer frame, demonstrates the idea.  Then it should be easy enough for someone skilled in building to extrapolate it for all sorts of situations.

An adjustable length trailer tongue is good for a few different reasons.  First, if you have a long load to carry – like canoes, for instance, that require a lot of space between the trailer and the tow vehicle.

A second reason is storage.  If the adjustable length trailer tongue can slide in for storage, or even be removed for storage, then it takes less space when not in use.

The above implementation is a permanent change of the trailer.  The trailer tongue is adjustable, but the main tube is permanent.  While it does the job quite well, there are a few things to keep in mind if you do it.

1. Do not drill in the top or bottom of the tongue tube.
   The top and bottom surfaces carry the most stress, so put the hitch pin (or pins) in the sides, not in the top or bottom.  See this Engineering Article about Stress for some good graphics.
2. Choose your tongue material wisely.
   Steel tube material in smaller sizes is often available in 1/2″ increments.  To get a nice set of telescoping tubes, use pieces that are 1/2″ different, with 3/16″ wall.  For instance, with our Mobile Gantry Crane Plans, we use 3″ x 3″ x 3/16″ wall outer tubes, then 2.5″ x 2.5″ x 3/16″ wall inner tubes.  Something similar will work well for an adjustable, telescoping tongue.  Just make sure the outer tube is larger than the trailer plans specified tongue tube size.
3. Wires.  Do be carefull with all the wires.  Figure out a good way so they will not split or crack or break or pinch.  Make sure the wires will not pull or snag when the adjustable length trailer tongue is long, or short, or transitioning between positions.

This is a simple adjustable length trailer tongue example.  The tongue tubes for telescoping are 4″ x 3″ x 3/16″ wall.  The inner tube is 3.5″ x 2.5″ x 3/16″ wall.  If it does not extend too far, this should be OK for a 3500 lb. trailer – possibly up to a 5200 lb. trailer.  (But do your calculations before building.)

Disadvantages of This Adjustable Length Trailer Tongue

There are 3 disadvantages of the above adjustable length trailer tongue system.  Yes, everything has both good and less desirable points.  These, however, are pretty minor.

1. First is the movement of the tongue member.  It will make some noise, and may add to a bit of harshness when towing.  The use of bolts to “clamp” the tongue can alleviate this negative.  Not a big deal for most people, but certainly something to know.
2. Second, it makes the front of the trailer heavier, and more costly to build.
3. Third, wires.  See above.

A Temporary, Tongue Extension ( for an existing trailer )

What if we only need the tongue extension temporarily?  I do not want to cut up my wonderful trailer just to extend the tongue once in a while, so is there a quick On and Off way to get a longer tongue – Temporarily?

Well, yes.  This is not as straightforward as it first appears, but it does work.  (Pitiful sketch done for a customer years ago.  But it was good enough!)

Build a T shaped bar to go under the existing tongue.  Connect it to the existing A-Frame tongue using 2 U-Bolts and a standard trailer ball.  The existing trailer connects the hitch at the ball in the middle of the T, and the U-Bolts connect to the trailer frame.  Some spacers may be required.

We DO NOT recommend heavy loads with this type of setup.  The added parts do nothing to strengthen the existing tongue even as they add a longer lever and more stress.  The concept is good to extend a trailer tongue temporarily, but not good as a permanent solution.

While it is technically an adjustable length trailer tongue, it is not infinitely adjustable.  As shown it has 2 positions, which for many situations is enough.

Caveats For The T Adjustable Length Trailer Tongue

See the rough sketch above.

1. Add a little material around the mid tow ball hole.  Both top and bottom on the tube.  This area will see a lot of stress.
2. You might need some spacers between the a frame and the ends of the T-bar where the u-bolts go.  Something to set the height of the hitch.
3. Add a bit of stiffening at the intersection of the T.
4. Go easy on clamping the u-bolts.  Use nylock nuts so they will not come loose, then just snug it up. Don’t crush it.
5. Load the trailer as usual assuming a 10-12% or so tongue weight at the EXISTING tongue position.  This tongue extension will decrease the load at your vehicle hitch, considerably.  However, you don’t want to overload the design of the existing trailer, so make your loads appropriate for the EXISTING tongue position.
6. Finally, you might want to put a piece of metal or hardwood between the top of the U-Bolt and the existing trailer frame to avoid damage.  This will spread out the forces from the U-Bolt.  (See this post for U-Bolts.)

This is a concept sketch only.  It works, but for a lightweight, specific application.  Please be careful choosing material, and build the adjustable length trailer tongue at your own risk.

Finally, for the electrical connection, make an “Extension Cord” with the correct connector on each end.  That will make a temporary electrical extension to go with the temporary way to extend a trailer tongue.

Adjustable Trailer Tongue Wrap-Up

As you can see from above there are a lot of ideas about ways to extend a trailer tongue, or make an adjustable length trailer tongue.  The range from easy to more difficult.  Also, a range from Easily Adjustable to Permanent.

If a longer tongue is needed on an existing trailer, there are ways to do it.  Likewise, if you want something adjustable for your new trailer build, there are ways to do that too.  Don’t be afraid of diving in to make something unique.  Again, these are ideas for you to modify and run with.

For more about ways to extend a trailer tongue, try this article about implementing a folding tongue on a trailer.  Then, the next article about what I learned, and what I would different if I build it again.  If you want a commercially available product (which is also the stimulation for building the folding tongue) read this article about a convenient folding trailer tongue.  These are not an adjustable length trailer tongue, but they do change the length for storage.

Have a Wonderful Day!

Are these articles helpful?
We appreciate your kind contributions.
Thank You.