4WD MODIFICATIONS - GENERAL MODS
Many 4WDs come with steering dampers that reduce unwanted reactions from the front wheels through the steering wheel. We checked out two Tough Dog units that differ from most others.
Steering dampers are fitted to many 4WD front ends and are absolutely necessary on vehicles fitted with ‘live-beam’ front axles, including Land Rover Defenders and early-model Discoverys; Jeeps; G-Series Patrols and all 70- and 80-Series LandCruisers.
Steering dampers cushion reactions of the front tyres to road conditions. Sharp bumps, corrugations and potholes can generate ‘shimmy’, particularly in the case of oversized wheels and tyres, and that’s precisely what a steering damper is intended to alleviate.
Adjustable steering damper
Because we’ve been testing Tough Dog’s adjustable suspension shock absorbers we thought it would be timely to check out the company’s adjustable steering damper as well.
Like the adjustable suspension shockers the damper has a dial adjuster at the foot that varies damping force through nine stages.
It fitted easily to our 75 Series and, with the setting on ‘1’, we noticed an immediate improvement in feedback reaction, compared with the tired unit we took off. For the loaded 75 Series – 1.4 tonnes weight on the front axle – the optimum setting was ‘4’.
At that setting the steering reaction damping was very effective, with not too much steering wheel rim effort required to manoeuvre the beast. We tried dialling up more damping and found the rim loading too much.
The advantage of the adjustable damper over a fixed-setting one is the ability to dial in as much damping and rim effort as you like.
‘Return-to-centre’ steering damper
Tough Dog makes several ‘return-to-centre’ steering dampers, to suit different vehicles. We checked out an appropriate model on our 75 Series.
All these Tough Dog models feature a shock absorber body and shaft, with an external coil spring clamped to the body via an adjustable collar. The spring extends and compresses as steering arm action cases the steering damper piston to move inside the body and that spring pressure is transferred to the steering arm, always trying to centralise it.
Optimally, the collar is clamped into position with the steering in the straight-ahead position, but may be given a very slight turn-right bias in the case of vehicles that are overly road-camber-sensitive.
Camber-sensitivity can be caused by poor wheel alignment or inappropriate tyre fitment and it’s important to note that a return-to-centre steering damper isn’t designed to cure these problems. Also, the spring pressure adds to steering effort and that may be undesirable in vehicles that spend most of their time metro driving.
In the case of our 75 Series a combination of 50mm suspension lift and 265/75R16 tyres on 8×16 wheels with 120mm positive offset has increased its road-camber-sensitivity, even with accurate wheel alignment. That situation is worsened when we fit test tyres that have little self-aligning torque, such as aggressive M/T rubber.
For our vehicle the Tough Dog return-to-centre steering damper has made cruising on sealed and gravel roads much more pleasant, by reducing the amount of steering correction needed. We haven’t found the steering effort uncomfortable around town and in off-road conditions, so we intend to give it a long-term workout.