Is the Discovery CDL similar to ARB lockers? The CDL once engaged, does it lock all four wheels? I saw that ARB lockers are separate from the rear and front if installed. Each locker distribute power to both wheels, right? So the CDL, locks all four? Can anyone explain?
Thanks

 

CDL locks front and back diffs
Lockers lock left and right on the front and back diffs.

 

Thanks. I'm still confused, isnt it that all 4 wheels are working at same time all the time? If you lock the front and back, what advantage can it deliver.

 

When cdl is locked and the lockers are locked, all wheels move as one. Without lockers, left and right work like front and back without cdl. When all are unlocked, power is transferred to least resistance diff and wheel.

 

To put it simply, the transfer case in the Discovery has a differential inbetween the front output (front driveshaft) and rear output (back driveshaft) This differential is "open" and therefore operates exactly the same way an open differential on your regular ol' axle. If we are talking about the open diff in the back axle on your 2wd Chevy pickup, you know one wheel gets stuck and the power from the driveline continues to be transferred to the wheel that is slipping...its the same case with this transfer case on the Disco. If you have that one tire slipping in the back, all power is being transferred to that wheel starting at the transfer box so now, not even your front tires are getting power because its ALL being transferred to that one in the back. Hence, the Center-locking differential which elminates that by setting a gear back that locks the front output and rear output shafts together, now distributing power 50/50 between front and back axles. Only then does it matter if the 3rd member differential of your wheel axles is able to achieve a limited-slip or "locked" condition.

So, in essence, a locking differential in your wheel axles does you no good without having the transfer case differential locked because the power is being transferred to the path of least resistance so that the locked diff of the 3rd member never gets any power to begin with.

This is only good for use off-road because the characteristics of a "locked" driveline are terrible for everyday, street use. The front tires must be able to rotate at different speeds from each other and from the back tires so that you can steer and turn your vehicle accordingly. Any differential that is locked in any part of the driveline is pretty much made to only drive on a straight path and forwards, the majority of the time.

 

Now as I understand if the CDL is engaged it will lock the front (which is still an open differential) and the back (also still an open differential) combined. So the power can be distributed diagonally (equally front and back) in a situation when the (front left tire) and the (rear right rear) tire is above ground, so then the rest of the tires touching the ground has equal amount of traction. Also, then if that is engaged it will still drive normally while turning. Also, its not like the concept of ARB which completely locks the front or the back.
Sorry, sometimes I'm mechanically challenged. I dont do off road and have an 03 and 04 which has some minor differences which I want to understand.
Thank you again.

 

close. power is distributed evenly to front and back axles, BUT the differentials of stock 3rd members are still open, hence the benefit of "ARB, Detroit, etc" locking/limited-slip diffs, only after the transfer case diff has been locked. But having that equal power to both axles gives such a good deal of power transfer that individual wheel slip threshold is much higher. Add to that the LR Traction Control System and supposedly you are in pretty damn good shape.
They say only serious off-roading and serious obstacles necessitate the need for locking 3rd member on a Discovery WITH center-locking diff. Are you thinking about modifying your transfer case to a locking unit? I just picked up the parts to do mine today.

 

Put slightly differently, with the transfer case (center) differential locked you should have power to at least one front and one rear wheel. They may both spin and leave you stuck but it's better than having power to just one spinning wheel and the other three wheels not moving at all.

 

With CDL and f/r differential lockers 4 spinning wheels still a possibility?

......

 

Im sure that is possible. That is why most off roaders have a winch to get unstuck. I believe that experience to counts a lot when to use or not to use the lockers. I just saw a video about this stuff. Cheers

https://www.youtube.com/watch?v=Pkfu...0#t=623.641562