(Diff locks and Limited slips)
Pneumatic actuated Locker with strenghtened shafts
As anyone knows who ever digged his rustbucket out: Traction is everything. Traction is achieved out of a lot of components.
Most important is that big nut that sits behind the steering wheel - the driver. I've seen world-class equipped cars being driven into the ground by careless or inexperienced drivers. But this is their poblem so lets assume you are all aces behind the wheel.
Second comes the tires. An tire not suitable for the type of road or terrain will bring you in hazardous situations. But tires are an different subject and will be discussed later and elsewhere.
Third are traction enhancements. Many people affirm if you have an soft enough suspension you will not need any lockers or LSD's. Even Landrover claims this loud and clear. They are wrong- dead wrong!
Remember last time you went into slippery mud? When you got stuck (at least with coil springs) there's a good chance you had all wheels on the ground- and only one wheel on each axle lost traction. The other one, high perched on the dry just stood there silly waiting to be rescued.
This is the way open differentials work. They better have to or you'd end in the first tree you encounter. This is great for travelling on hard ground but less than ideal in low-traction situations.
What's the way around this? The problem is as old as four wheel drive and so are most solutions.
Basically you have 2 options: Manual or automatics. Let's first see the automatics systems.
The manufacturers make difference between 2 systems again: Limited slips and lockers. Limited slips allow a varying degree of slip to one wheel and are theorhetically less effective than lockers.
First see the limited slip differential. LSD's come in a lot of different degrees of effectiveness and constructions.
One system relies on friction plates in the case. As soon as one wheel begins to turn faster than the other, the friction plates transfer some force to the other wheel. Advantages: Can be fitted to front and rear as their action is so soft- you almost don't notice them. Disadvantages: - you almost don't notice them. Also the friction plates need an special oil. And they have to be replaced sooner or later which involves some work and costs.
The second system relies on some sort of gear binding. Gleason-Torsen and Truetracs fall into this category to name just a few. Advantages: Soft action, much greater force transfering ability than friction models, no special oil needed, no need to look after them once they are correctly installed. They can also be installed into the front axle but we do not recommend it. Usually the last as long as the rest of the differential. Disadvantages: Initial price a bit higher than friction models, still no 100% lock.
A third system are the real automatic lockers. Detroit Locker or SoftLocker are some trade names. Once they detect an anormal movement of a wheel they lock the two halfshafts together solidely. No traction is lost then and you have 100% force at each wheel. They are built for serious offroading and offer an tremendous improvement over open diffs. Advantages: No maintenance needed, no special oil, sturdy construction. Disadvantages: Harsh engagement, they will definitely put additional stress on all components, you shouldn't mount them in front axles at all, even in rear axles increased turning radius.
All automatic systems have common problems: You never know exactly when they are in or out. Driving an locked system on icy road is a sure way to rise your blood pressure- believe me. Also you'll get less mpg and more tyre wear. Any of these systems will put some additional stress on the mechanical components, some systems less, some more.
Now for the manual systems. Basically they all work the same way: They lock both halfshafts together. The difference lies mainly in the way they do this and the actuation method.
-The factory offers traction controls on newer vehicles as the Freelander (Hey, didn't they talk about not needing a locker??). This system works by applying brake pressure on the single wheel that looses traction. They choose this system for they already had most of the components on board like the ABS-system to witch it's very similar. In theory this works well but has some disadvantages like added stress on the axles and hubs. I also wonder how this will perform after 3 or 4 years if driven into deep mud from time to time. I already have to pamper my standard brakes so they keep working. How about all this complicated stuff of electronics, connectors and senders? Wait and see.
-Real manual engagement can be made by different means: You pull a lever, push a button, turn a knob. So either by cable, by air pressure (vacuum or pressure) or by oil pressure. Prices differences between these systems are mostly caused by the more complicated setups you need. The degree of efficiency of all these is the same: 100%. However there's a big price difference in a system that needs one or two clumsy levers and one that just needs a button and a light.
What do WE have to do with this?
Easy- we supply most of these systems. We offer the following lockers and LSD's: Clutch type limited slip- heavy unit that uses 9 clutch plates per side Truetrack- A limited slip diff, maintenance free, very soft, can be installed front and rear SoftLockers- An automatic locking system. We recommend this only in rear axles but it CAN be mounted in front axles. After all it's your life... Cable actuated manual lockers - Toggle lever actuated solid lock, for Rover front or rear, for Salisbury 109 and 110 axles. All these can be combined e.g. with limited slips. Air locker - basically the same locker but actuated by air pressure. Includes air compessor and is actuated by pushbuttons. Almost all honest manufacturers advise on putting stronger components into the axle housing too. Of course we can also supply the following parts: 4-pinion carrier for 10 or 24 spline axles 4-pinion carrier for 10 or 24 spline axles built into your Rover diff and keeping your ratio 4-pinion carrier for 10 or 24 spline axles built into your Rover diff and changing the ratio to 4.1, 3.8 or 2.83 Strenghtened long and short halfshafts for front and rear To be honest we must tell that you CAN use your standard shafts. In front Discoveries and 90s have thinner 32-spline CV shafts (3.8mm thinner) than the 23-spline shafts fitted to Range Rovers. There's a kit that replaces these shafts with 32% thicker shafts. However this kit is not cheap. In any case a light foot on the loud pedal is the best faillure prevention. What to choose? It's up to you (that isn't a great help, is it?). Remeber that any engaged LSD or locker will have an influence on the steering behaviour. Also they produce some "interesting" reactions on icy roads! We'd recommend: Mostly street driven- none Occasional offroad- one automatic Truetrac or Torsen in the rear, none or (at the limit) another Truetrac/Gleason in front if you know what you are doing. Heavy offroad and working machines- manual locker in the rear and front together with strenghtened shafts and eventually clutch type LSD in front with manual override. Prices on all these on request. Only high quality parts- no cheep imports.