Re: [A/S] Re: A/S Tow Vehicle Shocks and Ride

["Oliver Filippi" <ofilippi@xxxxxxxxxxxx>]

Softer tires - less air pressure, or lower load range tires can soften the
hard ride slightly.  However, you also reduce the capacity and safety margin
in the process.

Different valving on the shock absorbers could also have some (though I
doubt cause a very significant improvement (softer) in the ride.  Shock
absorbers are a damping device, primarily to dampen the oscillations a
spring would go through after hitting a bump or rut.  Shocks are valved for
jounce and rebound. Jounce resists sudden upward motion while rebound slows
down the wheel as it drops from following the hitting of  a bump.  Thus a
shock with a softer jounce  valving might help a little. You might try
Bilstein shocks, as I believe theirs are adjustable (can be adjusted by the
installer for firm or soft).  Since most OEM shocks are not know for their
stiffness, I doubt that new shocks will provide a softer ride.

Unfortunately, the primary cause lies in the spring design on your vehicle.
Modern springs on pickups tend to be variable rate, which simply means that
they will initially flex more under a light load and get progressively
stiffer as the load increases.   (a conventional spring simply deflects in
direct proportion to the load, whereas a variable rate one deflects
proportionally less as the load increases)

Thus a well designed variable rate spring (especially on the rear axle of a
pickup) can provide a comfortable ride under light load, and still have the
capacity and control when the truck is fully loaded. They also require a
longer spring travel, which tends to cause the back end of the truck to ride
high when unloaded.

A well designed four wheel independent suspension will work even better, as
there is "no solid axle" across the rear (since each rear wheel is sprung
independently)  Unfortunately, four wheel independent suspensions are almost
non existent in trucks.  Ford hired a suspension engineer from Porsche to
fix the rollover problem on the Explorer. (The FOUR DOOR ONLY) model of the
Explorer now comes with a four wheel independent suspension.

Recently (2003 model year) Ford put a four wheel independent suspension on
the Excursion, which has gotten excellent reviews (the suspension that is).
For 2004, Ford is supposed to offer a  four wheel independent OPTION
(obviously taken off the Excursion)on some of their pickups (I don't recall
if it will be on the 1/2 ton, 3/4 ton or both).

Designing rear springs for pickup trucks (especially 3/4 and 1 ton models)
is a tricky business in terms of achieving a comfortable ride over its
entire load range from empty to fully loaded capacity.

Without taking sides, it is fair to say that Chevrolet (and GMC) have been
the most success in achieving a comfortable ride in their 3/4 ton pickups
over a wide load range.

There is a fix you can make, however.  It would include installing softer
rear springs AND a set of air bags (Air-Lifts) [NOT AIR SHOCKS].  This would
still give you the load capacity and a level ride, and a comfortable ride.
You probably won't get much help from your dealer, but a truck spring shop
would know what to do.

Good luck.

Oliver Filippi