I have a 2000 Disco II with the CDL. I will be buying the kit that allows me to engage the lock while inside the car as soon as I find a good one. My understanding of how the CDL works is that when engaged, both the front and rear wheels are "locked" and spin no matter what. When the CDL is NOT engaged, the wheels revert to normal Limited Slip Differential.....am I correct in my understanding? In addition, would there be any advantage to buying air lockers or would I just be wasting my money since the Disco II's (99,00,04) come with the CDL which essentially does the same thing..

 

First, Discos don't have limited slip, they have open diffs.
When the CDL is engaged, 50% of your engine torque goes to the l/f the rest to the r/r. If and when you are slipping, the ETC will transfer power back and forth between the 2 tires on each axle.
To have all 4 wheels with equal torque you will also need to install front and rear lockers.

 

As far as I know it's all in the traction control system, other than that we have three open differentials. I haven't really had a chance to see how well it works, but there is no way it's as good as a locked diff, whether it's an air locker, Detroit, Lincoln, etc.. The CDL only locks the diff between the 2 axles, you still have the open diff between the wheels.

 

CDL locked, 50% power to the front axle and 50% power to the rear axle, then the traction control uses the ABS system to keep individual wheels from spinning.

 

Coild someome contrast this with the way a Discovery I 4 wheel drive works???

 

Yes.
It works the same as the DII only without traction control.
So if a wheel is spinning it will keep spinning.
Does that help?
The CDL worksthe same.

 

So when you move the lever to the left to diff-lock its not Truely locked?? All 4 wheels dont spin at the same rate??

 

No, all four wheels do NOT all spin at the same rate, you couldnt turn if they did.
When the center locking differential is locked then equal power goe to the front and rear axles but the differentials on each axle still allow each wheel to turn at different speeds.
If you cross a ditch and your left front wheel is in the air it will spin and the right front wheel which is still on the ground will have little to no power because the power goes to the wheels with the least resistence.
On DII's the traction control stops this from happening by using the ABS to stop the spinning wheel, this then sends the power to the other wheel.
If you have lockers then both wheels will have equal power no matter what as long as the locker is engaged.
You only need lockers for really serious off roading. Good tires anddriver skill will get you through 95% of what you will encounter.

 

When the diff lock is engaged, you will ALWAYS get atleast2 wheels that spin at the same rate(1 front and 1 rear)The Disco has 3 open diffs (until you lock the centre).

If you add a CDL to a D2 with TC, then the TC will control the remaining spinning wheels front to rear AND across each axle. Having a CDL and TC is as close as you will get to having lockers fitted.

A D2 with a CDL and TC is a pretty awesome combination, and it will take some pretty extreme stuff to stop you in your tracks

 

Unless your 3 amigos are on, then you may as well be driving a H2.