Date: Wed, 22 Aug 2001 11:23:57 -0600
Reply-To: John Klun <jklun@GJ.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Klun <jklun@GJ.NET>
Subject: Trailer Fishtailing...
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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
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