Leaf Spring Suspension
Series Land Rovers should ride and handle with comfort and precision. Ed Evans explains why they often don’t – and shows how to improve and maintain the standard ride
156 Series Land Rovers should ride well. If yours doesn’t here’s how to improve it
Any Series Land Rover with its original leaf spring and telescopic damper suspension system should ride well. If it doesn’t, it’s not because of an old design that’s rough and ready, it’s because something is wrong. The truth is that a Series vehicle should ride and handle well. Admittedly, ride quality may fall short of modern standards, especially in a Series I, but they aren’t so bad as is often assumed. Indeed, a long wheelbase model can give a tolerably smooth ride, and a short wheelbase model can be predictable and tight in its handling. Steering obviously also affects handling – and that means front wheel toe-in, steering joints, steering box, steering relay, drag link, track rod, steering damper (where fitted) and tyres all need to be in good order. But steering is a whole subject on its own so, assuming the steering is well maintained, we’ll concentrate in this feature on the suspension.
Suspension condition can be difficult to assess because the components deteriorate gradually and we naturally adjust our driving style to compensate, unaware of the deterioration until we drive someone else’s refurbished vehicle and immediately notice the difference.
It’s all fairly simple, though. All we have at each wheel corner is a damper, a spring and some bushes. Check and maintain them, replace them with quality items if needed, and the wagon should roll like it’s new. Here’s how to check the parts and keep the ride like new.
DESPITE DAMPERS being referred to as shock absorbers, it’s actually the springs that absorb the shocks, while the dampers control the springs’ movement so the vehicle doesn’t keep bouncing after hitting a bump. So, bouncy vehicle means defective dampers, simple as that.
Dampers also control the rate at which the spring deforms and returns back to shape, and they are matched to suit the spring. Incorrect dampers can spoil the ride and the handling, as can nonstandard springs such as parabolics or replacements of non-standard spring rate when fitted with standard dampers. So when fitting non-standard springs, the dampers should be changed to match, and it’s reasonable to expect the spring supplier to know the correct damper to fit.
Dampers are best assessed when driving. Look for a tendency to swerve under heavy braking, or the front-end diving. Excessive cornering roll is likely to be caused by defects in the dampers rather than the springs. Also look for leakage, and for corrosion holes in upper skirt allowing dirt onto the shaft, though these two checks don’t necessarily confirm damper performance.
Land Rovers are a tad hefty to use the corner bounce test. Try it though – pull the vehicle down hard at each corner in turn and watch it bounce back up and stop. If it keeps on bouncing, the damper is not controlling the spring – replace them only in axle pairs. Regardless of all other tests, if the damper condition is doubtful, then it’s necessary also to test them off the vehicle. Hold the bottom eye of the damper in a vice and extend and compress the top of the damper by hand. The resistance should feel the same through the full movement in both directions. If there are slack spots, or sections of differing resistance, the damper is done.
When testing, keep the damper vertical after removing from the vehicle, and mount it vertically in vice, as on the vehicle.