The TC reacts once one or more wheels have already lost traction. You lose some forward momentum as the TC starts working which can cause the truck to get stuck cause now its just digging down deeper into the low traction surface while braking the spinning wheels.

The CDL proactively helps to keep the truck moving as long as 2 wheels on the same axle have traction. You dont lose forward momentum which helps maintain rolling traction.

 

^^this^^

 

I see some use the ebrake at times to help gain traction....does this just cause redistribution of power to the front?

 

One thing about the TC system in the Discovery is your brakes need to be in good working order, so weak pedal, worn pads will all impact it. And 3 amigos it does not work at all.

 

the e-brake on the disco works on the rear output from the transfer case. my guess would be that using it with an unlocked t-case would force power output to the front wheels. if it's the front wheels that are spinning, it's not going to help anything.