[VAC] Misfortunes on the road

[John Anderson <janderson@lsol.net>]

Nick, tough break on losing the rear compartment cover.  I lost mine (66
Sovereign) a few years ago--it had not ever fit just right, had been
modified with a couple of cheap hardware latches by a previous owner,
and one day it blew or fell off about 5 miles from home.  I realized it
was gone within 15 minutes and drove back to search--and I found it--but
of course a Greyhound or gravel truck or something had flattened it by
that time.

I made a temporary replacement out of plywood covered with sheet
aluminum, but finally called Andy Rogoshinsky at Inland RV, got what
appears to be an exact replacement, (for a mere $225.00!) and have been
happy but nervous ever since.

Time has passed, and I no longer keep it strapped in place with a bungee
cord everywhere it goes, but I have added a regular latch check to my
travel routines, and have adapted a set of sleeve-and pin-type latches
to keep it from jiggling loose again.

Inland RV has been mentioned in various contexts from time to time on
this list.  I have ordered various parts from them over the past 5 years
or so, most recently in June 1998.  I have heard they have had some
problems.  Others on this list might know if they are still in business
or not.  Their prices usually seem high, and sometimes what you get is
not exactly what you expected when you placed your order.  However, the
cover they sent me was the real deal.  If you want, contact me off list
for the address.  Maybe they can get more...mine was said to be on "back
order" (from where??) and it took a while to ship.  You would come out
ahead, though, if you could find a good cover off a salvage trailer,
like one of these gutted trailers that sells for $500.

The bigger picture: funny things happen to objects in motion when
external "excitation" forces interact with them.  Many (if not all) of
them are related to velocity.  On a highway, think about all the
excitation forces at work: you have the interface between wheel and road
surface; skin (and surface projections) and the surrounding air; the
flexing between the trailer frame and tow vehicle; and of course all the
associated disturbances caused by passing/meeting vehicles, uneven road
surfaces, imperfect wheels and tires, braking and acceleration, and
various others.  You describe what appears to be the result of a
persistent steady-state harmonic, which can even be induced by the flow
of air over your tow vehicle creating turbulence that affects your
trailer.  You can look all over (and you should!) for spring, shock,
tire, wheel, and hitch looseness or imbalance or other problems, but the
answer may be as simple as 1) adding an airfoil to the rear of your tow
vehicle, and 2) toning down the velocity you are traveling at.  Number 2
is cheap and eminently sensible, when you consider the time it takes to
back track looking for missing parts.  Note that velocity-induced
harmonic vibration doesn't just decrease when you adjust (read: lower)
your velocity to get outside of the critical range; it actually goes
away!

Loc-Tite is good stuff for loose screws, but your panel/segment joints
are feeling the same thing those screws are, along with your vent and
window operators and everything else.  When they let go 1000 miles from
home, it gets real grim!

I hope this perspective helps--

John