
Picking the best leaf spring
for YOUR Land
Rover
Vehicle suspension springs are a compromise. The softer the springs
are the more they move in response to bumps and the more they can
articulate within the possible range of motion. The stiffer they
are the more weight they can carry both on and off road and the
less the body leans on corners.
The compromise is to find the spring rate that provides the most
comfortable ride and best articulation for a vehicle's, intended
axle weight range (from empty weight to full passengers and cargo).
Rover went to a great deal of effort to come up with the best spring
rates for each model of their home market vehicles (right hand drive
versions). There are five different springs that Rover has used
on the front of series II, IIA and III Land Rovers to tune the front
suspension. With a little weighing and effort you can take advantage
of the variety of available springs to fit a set of springs that
are optimum for your vehicle.
The first thing to note is that Except for the 1- ton rear springs
Land Rover springs come in handed pairs. This is a result of Rover
fine tuning their springs for uneven side to side weight distribution
of home market vehicles. Starting with the series I UK model there
was more weight on the driver's side in the form of the driver,
battery and fuel tank.
So to provide the softest ride and a vehicle that sits level they
put stiffer springs under the driver's side rather than beefing
up the pair of springs and making the ride harsher.
This was fine for the home and most colony markets where vehicles
are RHD, but didn't work all that well for 109 station wagons nor
for left hand drive Land Rovers. The 109 station wagon has the fuel
spread out evenly across the rear so the handed weight was reduced
to the driver and battery. Left hand drive Land Rovers have the
weight of the driver on one side balancing the weight of the fuel
tank and battery on the other side. The result is a similar weight
on each front axle.
A left hand drive Land Rover with new handed springs will almost
always sit listing to the right. Sometimes by as much as 6 inches
if heavier duty springs are used on a Land Rover with a front fuel
tank.
Rule #1 for left hand drive Land Rovers
is never buy a handed pair of leaf springs unless you know the individual
axle weights and one side is about 150 pounds or more greater than
the other side.
Rule #2 The less weight a spring is rated for the
lower that spring will ride at empty weight (they all should
be close to the same ride height a max on pavement load),
This means a 109 will sit higher with 1 ton springs than it will
with regular springs.
Rule #3 The softer a spring is the greater the range of
articulation until the articulation boundaries are met (ie
frame stop, check strap or shock max. extension length)
Rule #4 Within reason, the closer a spring gets to it's
max load weight the easier it can flex. This means
a softer ride
The next thing is how to decide what spring rate to choose:
Below is my interpolation of data provided
by Land Rover. Minimums and maximums are conservative approximations.
These numbers should be taken as best guess approximations based
upon weight ranges that Rover used each spring with and not as absolute
limits.
Load your Land Rover to the maximum weight you plan to take off
road plus full fuel tanks then weigh it at a public scale. Choose
a spring for each axle from the table below that has a maximum rate
closest to but greater than your vehicle's axle weights. This should
get you the softest ride and best articulation with springs able
to handle your off road driving needs for the way you load your
vehicle. If you do not carry heavy weights in the rear, you may
well be over sprung in the back and dealing with a harsher ride
over those washboard roads than you need to.
As an example, The Green Rover weighs 2460 pounds on the
front axle and 2980 pounds on the rear axle, fully loaded for trips
with me and my dog in the vehicle. Side to side axle weights are
less than 150 pounds different.
From the chart below, 276034 springs on the front and 279678 springs
at the rear would provide the softest ride, best spring movement
(articulation) and safely handle my Rover's weight off road.
If you want to achieve the smoothest ride and best articulation
from those springs there are a few things
that can be done.
88 & 109 FRONT SPRINGS
Spring number |
Minimum weight |
Maximum weight* |
242863 |
1600 |
1700 pounds |
241283 |
1700 |
1850 |
264563 |
1750 |
1950 |
265627 |
1950 |
2275 |
276034 |
2275 |
2550 |
* Maximum weight is maximum recommended cross country weight.
88 REAR SPRINGS
Spring number |
Minimum weight |
Maximum weight* |
517589 |
1300 |
1950 pounds |
517588 |
1950 |
2650 |
109 REAR SPRINGS
Spring number |
Minimum weight |
Maximum weight* |
279679 |
1450 |
2500 pounds |
279678 |
1500 |
3570 |
535173 |
1800 |
4200 |
Happy spring tuning!
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