John & list,

What you are calling fish tailing sounds like what I call sway.  It is a
result of improper load distribution on the trailer.  There was too much
weight towards the rear, which resulted in too little weight on the tongue
of the trailer.  I learned this lesson years ago when hauling cars on
various flat bed trailers.  I even had a van & loaded trailer turn 180
degrees around on the Ohio Turnpike.  It is interesting to sit in the middle
of the road & watch traffic coming at you.  The highway wear & rain grooves
affected your tow because of the improper distribution, but were not the
cause.

I do not remember exactly how much weight you want on the tongue & I believe
it changes with the trailer size & weight and the hitch class.  Proper
tongue weight is very, very, very important.

Walt Spak
Pittsburgh, PA.
wnsopc3@3rdm.net

----- Original Message -----
From: John Klun <jklun@GJ.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, August 22, 2001 1:23 PM
Subject: Trailer Fishtailing...

> Hello Volks-
>
> A few days ago, someone sent a posting about their fishtailing problem
when
> hauling a trailer.  Here's my two cents worth.  (Alas, not really Vanagon
> content but applies...)
>
> About 2 weeks ago, I had the 'opportunity' of hauling, from Dallas, TX to
> Delta, CO, an 18'X7' trailer (weighs about a ton) loaded with about 2-3
tons
> of equipment behind a Ford F-150 X-Cab with a (get this) 302CID engine-
and
> an automatic to boot!  Yikes!  We found out later that the trailer brakes
> were not working or even installed.  Dumb and Dumber!
>
> There was so much weight behind us and so little power, it took forever to
> get up to speed.  We also suffered from that 'harmonic' fishtailing that
was
> mentioned.  We found it was set off by the difference in wheel widths
(truck
> 6', trailer 8') going over rutted highways.  All the way from Dallas to
> Clines Corners, NM, the highways had grooves in them from heavy trucks
> driving in the same spots.  We also noticed that the fishtailing was
caused
> by too high a speed and trucks passing us at high speed- especially with
> high cross winds.
>
> We didn't seem to have any problems wherever the roads had fairly fresh
> asphalt laid down- such as I-40 in New Mexico.
>
> The scariest moment I had was when we were traveling, balanced steady, in
> the grooves at around 65 (speed limit was 75) when we were passed by an 18
> wheeler doing about 80 and there was a crosswind blowing from the driver's
> side.  We immediately started fishtailing so bad that I thought I was
going
> to lose it.  Nothing that I did could stop it and only made it worse.  I
> kept over correcting without trying to.  Finally I resigned myself to the
> possibility that it was all over and let up on the wheel.  Lo and behold!
> The fishtailing reduced dramatically!  And I was finally able to get it
> under control.  Yes, I did let up on the gas but not enough to jack knife
> and yes, I kept my foot off the brakes for the same reason.  The only
other
> thing that I noticed that helped besides taking my hands off the wheel was
> steering the truck and trailer half on/half off the shoulder.  That
steadied
> the fishtailing some.  Next time- it will be a heavier truck with a more
> powerful engine.
>
> Surprisingly, we didn't have much of a problem on the mountain passes.
> Obviously, with that heavy a load, we were in 1st gear all the way to the
> top at around 10-15 mph.  I kept it in 1st gear on the way down as well
> never letting our speed get more than 30 mph over our base speed.  I
braked
> heavy to get down to the base speed and continued doing that until the
road
> leveled off enough to shift into 2nd/3rd.  The brakes were fine coming
down
> this way.  There was one 8,000' pass where I got very cocky and didn't
leave
> it in 1st long enough coming down (it was steep) before shifting.  We paid
> for that by almost losing it and when we finally stopped in a pull off,
the
> brakes were glowing red in the dark and the right one was smoking like it
> was on fire!  That's when we found out we had no trailer brakes... (don't
> ask).  After that episode, the trip was very uneventful.
>
> John