Mike,
All
springs will settle over time, however I believe your question should be
"How much will springs settle shortly after being installed?"
The
answer is very little providing the springs are the right
springs for the vehicle.
Springs
support weight and this is why it is so very important to be honest
about the changes made to the vehicle. For every change there can be a
change in the amount of weight the springs will be required to carry.
Another
function of rear leaf springs is to control axle windup which
occurs both on acceleration and braking. So engine size, torque and
horsepower may come into play. Standard design stepping may be
alright or if the power is such special stepping my be required.
Correctly
manufactured springs, both leaf and coil, are shot peened which removes
stresses in the metal which occurs during the heat-treating process. The
life of the spring is not only increased because of shot peening, the
spring will not continue to take "a set" once it is installed.
While
getting the overall stance correct will be one of the final steps in
building the vehicle, planning for it must happen early in the building
process. Getting that look can be tricky but most of the time it can be
achieved.
Because
springs support weight, the final look of the vehicle can not be
achieved until the vehicle is 99.98 percent done. Remember all those
parts which are waiting to be installed have weight. And the location of
those parts determine how that weight will be carried by the suspension.
Having you and your 4 buddies stand on the front bumper does not
distribute the weight in the same fashion as an installed engine and
tranny does.
Other areas
to watch for trouble include; Clearances - the look might be right but
things are hitting underneath. Steering -, the look may be nice but you
can't turn the wheel. Ride quality - the look may be nice but it rides
like a buckboard.
The
vehicle being built is custom. Things are being done to it and for it
that were not originally designed for it. More than once you will
install, remove, tweak, re-install, re-remove, re-tweak and repeat the
process over and over to get it "Just Right." And the springs
are no different, they may have to be installed more than once to get
the stance "Just Right."
The final
test of the springs is drive the car like you stole it. Work those
springs. Bounce them. Flex them. Stomp on the gas. Stand on the brakes.
Make them do their job, after all you built the vehicle to have fun, so
go have some.
So how
much settling is "very little?" Correctly matched springs will
settle no more than 1/4 to 1/2-inch once the car is finished and driven.
Any more than that means something is not right.
And, no
leaf springs will not settle any more than coil springs, nor will coil
springs settle any more than leaf springs.
Where do
things go wrong with springs that settle too much too soon? Bottom line
is over 99% of all spring problems are either installation related, a
result of the customer not being honest about the changes made to
the vehicle or making more changes once the springs have been built.
Springs
that continue to settle quickly after they have been installed are
over-stressed springs. Over-stressing is only caused by too much weight
on the springs.
Moving
on, all springs have a finite life, that is one day they will break.
How long this life is depends on their use, the loads they have been
asked to carry, the roads driven on, how the vehicle and the suspension
are maintained.
Any leaf
that is broke at the axle shows that the u-bolts have become loose. And
once one leaf breaks other leafs will also began breaking.
Can a
broken leaf cause an accident? Yes it can. Depending on which leaf it is
and where it breaks and does the broken leaf stay in the spring pack or
not. So don't mess around, replace broken springs ASAP.
Because
of the dangers of a broken spring, are mono leaf springs a good thing?
Mono Leaf Springs
will help you decide.
And
Mike, you thought you asked a simple question, didn't you?
- Mike
|
