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From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Which hitch lock?
Date: Mon, 26 Mar 2001 02:18:48 -0500

Kenneth Shelton wrote:

> Does anyone have thoughts on which hitch and coupler locks to buy?  These
> dead bolt locks look handy, keyed alike, do they work OK?
> Any other suggestions?

I had one of those or one similar to it. I misplaced the key so I
just clamped a vice-grip around one end and easily snapped the
tumbler right off.  I was impressed! (NOT!)

The one I like the best is the one made by Master that looks
somewhat like a shallow horse shoe and slides over the whole hitch,
encloses the release mechanism and blocks the ball hole.  I have no
idea if they make one large enough for the large trailer hitches or
not.  If your hitch is welded on, I also like the ball and flange
gadget along with a good padlock.  The ball fits in the hitch and
the flange prevents access to the hitch parts.  The weakness is that
one can snap vice grips or a crescent wrench over the latch lever,
bend it back and forth til it breaks, then the gadget and the hitch
guts fall loose.

My restaurant and apartment are in a fairly high property crime
area.  The solution to protect my utility and concession trailers
has been to drill a hole through the hitch on the back side of the
ball socket (toward the trailer) so that I can fit a large padlock
through the hole.  The lock blocks the ball hole.  Since the lock
hangs loosely, it is very difficult to get a good enough grip on the
lock to break it.  This lock and a chain around the frame and
through one or more wheels has done the trick so far.

From: John De Armond
Newsgroups: rec.outdoors.rv-travel,alt.rv
Subject: Re: anti-theft hitch coupler locks
Date: Sun, 25 Jul 2004 02:15:44 -0400
Message-ID: <>

On Sat, 24 Jul 2004 22:17:11 GMT, GaryO < @ . > wrote:

>I've recently observed several travel trailers which had been left
>parked along the highway without their tow vehicles.  This got me to
>thinking about getting a coupler lock in the event I should ever be
>forced to do this.  i.e. the truck becomes disabled and is towed off
>for service.  I realize that no lock will stop a determined thief, but
>it can prevent the opportunistic one.
>Does anyone have a recommendation for an anti-theft hitch coupler
>lock?  The ones I've seen so far are these:
>Fulton offers two models under the gorilla guard name:

This is a horrible design.  Those sharp-edged locking grooves are stress
risers that would respond to a couple of bends from a large crescent wrench or
channel locks by snapping right off.

>Master lock also offers one:

This one is better but is still limited by the strength of the hitch.

I have a friend who is a fireman by day and a repo man at night.  I've ridden
along with him on occasion.  He has a nice collection of tools and techniques
for repoing a trailer.  Not caring whether the hitch is destroyed opens up
many new techniques.

Many locks are still made of metal that responds to the CO2 fire extinguisher
trick - chill the metal with the extinguisher until it is below its
nil-ductility transition point, then whack it with a hammer and watch it break
like glass.  This problem was made known by the TV news shows in relation to
The Club many years ago so there's no excuse for this but it's still

If the hitch is protected by that last Masterlock or one like it, the solution
is to snip the coupler on either side of the retaining fastener using whatever
tool is appropriate and whack the lock to make a leaf fold out of the hitch.
The lock is removed.  The hitch is destroyed in the process but that doesn't
matter.  He has a special "ball" to address this.  It has a small ball, about
a 1-7/8 dia I'd estimate, with a hardened point machined on top.  The bottom
of the ball has a hole drilled up through the shank for an inch or so.  he has
a clamp that looks somewhat like a husky C-clamp but has points instead of

He backs up under the hitch using air bags to raise and lower his truck.  He
lifts up the tongue by the point which embeds itself in the hitch metal.  Then
he applies the clamp.  The non-threaded side has a post that fits up into that
hole drilled in the ball shank.  The other side has a hardened point that
screws down on top of the hitch opposite the point on top of the ball.  This
either pierces the hitch metal or nearly so, forming a very rugged pivot.
Then he drives away.  If the points slip, the ball takes up the slack.

The hitch is, of course, destroyed by this technique but the repo man doesn't
care.  He's not traveling far.  A new hitch can be attached later.

Like slim jims and other such tools, the repo man doesn't think up this stuff
on his own - he learns from thieves.

One of his most recent acquisitions is a portable plasma cutter powered by an
inverter installed in his truck.  With the plasma cutter, any metal melts away
like butter.  He can simply cut the lock off.  The unit makes very little
noise, very few sparks when he cups a heavy kevlar glove under the cut and is
very fast.

I just don't think there is any significant risk from casual theft.  I just
can't imagine someone seeing a trailer on the side of the road and suddenly
deciding to steal it.  It may happen but I believe it is MUCH more likely that
experienced thieves will do the stealing.  Experienced means they will be
equipped with at least some tools and know how to defeat most all common

What that means to me as an owner is that I have to present defence-in-depth
using multiple devices.  For my concession trailers I do the following.

I have a coupling lock on the hitch.  It's a Master brand but not that one you
referenced.  It has a cast steel body that totally envelopes the hitch and a
hardened pin that sticks into the ball space.  I have tested it and know it
won't fall to the CO2 trick.

My second level of protection is to block up the axles and let all the air out
of the tires.

My third level is to loop a large hardened chain through the holes in the
spoke wheels and lock it with the biggest Master lock the make.  The idea of
big isn't so much strength as it is to make it impossible to fit the chain
into anything but the largest bolt cutters.

At the restaurant I have custom made hardened eyebolts set in the pavement
that I attach a separate chain and lock to and thread through both the frame
and the axles.  I have all these locks keyed alike so I don't have 10 lbs of
keys to carry around.

If I have to leave a trailer on location for any period or if I was ever
stranded on the side of the road I take the wheels off of one side and take
them with me.

No combination of these techniques would stop a thief half as equipped as my
repo man buddy.  But each step is an added deterrent to encourage him to go
looking for easier targets.  And each step introduces more time into the
equation - time to hopefully let someone notice the activities and call the

A couple of years ago I had a trailer stolen from my parking lot.  It was one
that I had custom-built to haul around a large BBQ pit.  It consisted of
little more than a frame with a pair of forks and an axle.  It picked up the
pit Dumpster-style.  Worthless to anyone but me, or so I thought.  I had a
coupler lock and a lock through the coupler handle in place.  And I'd let the
air out of one tire.  The thief beat the locks off - I found pieces of lock
and coupler on the ground - and apparently aired up the tire.  Anyway, I woke
up one morning and found the trailer gone.  That's what got me to studying the
problem, consulting with my friend and devising the defense-in-depth

Oh, and whenever possible I keep the trailers hemmed in with other vehicles.
Not practical out on the road, of course, but that works great in my parking

One other thing. If you have the type of coupler that is bolted onto the
tongue, by all means have it welded on.  A bolted coupler can be unbolted and
a replacement one sans the lock bolted back in place in minutes.  Especially
since cordless impact wrenches have gotten so good.


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