Taction Aids

[Steve_t647]

Should I fit traction aids? Are they the answer? What was the question?

Many people believe that a 4WD and traction go hand in hand… you can’t have one without the other. However, your vehicle’s standard (or open) differential is designed to allow each wheel to turn independently, thus eliminating binding during turns. Off road, this becomes a major burden as engine power will take the path of least resistance, which occurs at the wheels with little or no traction. When the vehicle turns a corner, torque is transferred to the wheels that experience the least resistance (inside wheels will rotate freely and power is delivered to the outside wheels) to prevent tyres from scuffing and wearing out prematurely.

Because the standard differentials transfer the torque to the wheels that encounter the least resistance, you will loose drive when on loose/slippery ground or if one wheel is suspended in mid air. This becomes a problem as the wheel will spin and will not allow the wheels on firmer ground to drive the vehicle out of the situation.

Okay you now think you need some options well lets see...

LSD No we are not going back to the 60's... There are one of the factory options some manufacturers got it more right than others (Nissan and Pajero LSD are good examples) and toyotas (pre presureised clutch pack) is not so good but the toyota ones can be modified to provide the performance you want by any good 4wd shop. These work thew same as an open diff but transfer some of the power to the wheel with traction. Lockers (Some more expencive some less) but they all work in the same basic way, they lock up the "planetary or Spider" gears (not to be too picky on operation) to drive both wheels at a constant rate.

So what types are there and what is best? Well best is personal to you, just like women, one size does not fit all but anyway off topic.

LSD:
An LSD uses specialised oils that heat up and create additional friction. This additional friction is transfered to the clutch packs and drives some power (defined by the friction and heat of the oil) to the non spinning wheel.

Electric Lockers:
Well as you know most farmers drive Toyota and to this end Toyota introduced electric lockers in their Landcruiser range, these are designed to only engage under 5kmh, in a straight line and are driven by a small motor.
They work well but can be slow to engage (find that leaverage) and dissengage for this reason are not used a lot in competition, general offroading they are used and work very well, most people do not need an instant on locker and these are great units, they can also be manually manipulated if required.

Air Lockers:
The operation of the air-locking differential is simple and straightforward. Utilizing compressed air, the internal selector ring will engage the locking ring. Unlocking the differential involves the pressurized air being redirected through an exhaust port on the solenoid valve. This is the "Pisssht" sound you may hear, they are fast and depending on the shock load you want to put stuff through they can be enabled and dissabled at the flick of a switch they lock at speed and disabled for tighter cornering (very fast) before re-locking if the need is there.
These are commonly used in competition and work very well in all situations.

Vaccuum lockers:
Well these are a bit more picky with engage and dissengage but are factory fited to some Safari's, in general they work well but the parts are harder to buy than moon rocks! some change their operation to positive air pressure they are a very good locker to have but you may want to check its condition. They are sort of half way between Air lockers and Electric in operation.
They are a great option if you have a factory one or can find one cheap but they can only partially engage if there is not enough vaccuum or a kinked air line.

Lunchbox lockers:
These drive both wheels except when the vehicle is turning on a hard surface, all wheels are being driven equally therefore the vehicles traction is significantly improved.
As a full timed locked diff would be hard to turn these simple devices unlock the faster moving wheel (outside wheel on corners).
Yes there is a bit of a learning curve to them they click bang and pop on occasion but they do work. It will increase your turning circle too, the longer the wheelbase, heavier the vehicle and the larger the tyres the better they tend to behave. I have driven with lunchbox in a SWB safari on the motorway and almost had to change my underwear, the owner just said "oooh that made me pucker for a sec" but I have one in my double cab hilux and it behaves a lot better, just like the lingerie you will get used to it.

Things to remember:
Electric lockers need power, the litte computer dodad and the motor all to go to lock and water damage etc can affect this.
Air lockers require air pressure, air lines, seals and a compressor, all this is needed to have good seals these can leak and o-rings may need replaced.
Lunchbox lockers have some unwanted habbits but are learnable, knowing mine I am cautious about letting someone else who has only driven cars just junp in it
LSD's require specialist oils or an additive, the clutch packs can wear but they can perform well enough and are less harsh on running gear.
You can mix and match I run both LSD up front (to save blowing CV's) and a locker in the rear.