Totally stupid newbie question - CDL

[Lriwater]

Okay, I know I should know this . However, what does the CDL do for you in addition to traction control? I thought the traction control "simulated" diff locks. I tried the search function.
Thanks,
Chuck

 

[rcshauger]

50% of power to front axle and 50% to rear axle.

The TC approximates a limited slip differential in the best case, not a locking diff.

 

[keepitwildtv]

No, an open center diff can send 100% of the power to the front or back, and in poor traction an open center can sent 100% of the power to one wheel. I've experienced this in a FC-101 in the sand of Botswana. One wheel was throwing sand and no other wheels were moving. On those there's a pull lever that locks the center and off it went.

With a locked center diff a minium of one wheel per axle must be turning or it will kill the engine/snap something.

Daniel

 

[KDamericano]

A locked diff is just that-- locked at 50/50 output, which makes it unaffected by wheel slip. Traction control in the case of the Disco is done through the brakes and requires a wheel to begin to slip before it can engage, which simulates a "limited slip" diff.

 

[JustAddMtns]

http://en.wikipedia.org/wiki/Differential_(mechanical_device)
________
W463

 

[Hayes]

Really, a conventional open diff splits torque 50/50. But it only sends torque equal to the maximum that can be supported by either end. So if it only takes a few ft lbs of torque to get one end to spin, then the other wheel only gets a few ft lbs as well. This is where ABS-based traction control comes in--apply friction to a spinning wheel-->it supports more torque-->so the other end of the diff gets more torque as well.

A locked axle puts up to 100% of the available torque to either end--proportioned perfectly.

 

[pdogg]

All I can say is my non-CDL, 4ETC only Disco, works just fine..

Just keep a light amount of gas on, when the going gets tough.. the amount of wheel spin is minimal usually..

I know many people on this board give it a bad rap, but I cannot say anything negative about it... I easily tackled stuff this weekend, that CDL trucks had major problems with. Most trucks with only Center Diff Lock, have open front and rear diffs... The 4ETC is far superior to this setup in my opinion...

Fully locked front, center, and rear is the offroading utopia...

 

[keepitwildtv]

Open Diffs only split power 50/50 under perfect traction. Otherwise it's whatever wheel having thre least traction.

Locked all the way around is best.

 

[KDamericano]

No. An open diff splits torque at 50/50. A locked diff can apportion the torque up to 100% to the side with grip.

http://auto.howstuffworks.com/differential.htm

From wikipedia -

A locking differential is designed to overcome the chief limitation of a standard open differential by essentially "locking" both wheels on an axle together as if on a common shaft. This forces both wheels to turn in unison, regardless of the traction (or lack thereof) available to either wheel individually.

 

[p m]

goddamn... now quotes from Wikipedia are wielded like weapons.

KD - how about that: open diff splits torque 50/50, when you lock it, 100% of torque is delivered to the wheel on the ground, and 0% - to the wheel in the air.
Does it qualify as apportionment?

 

[KDamericano]

goddamn... now quotes from Wikipedia are wielded like weapons.

KD - how about that: open diff splits torque 50/50, when you lock it, 100% of torque is delivered to the wheel on the ground, and 0% - to the wheel in the air.
Does it qualify as apportionment?

much better - i was just going to add that a locked differential is the equivilant of removing the differential all together

 

[rcshauger]

Just to clarify... axle differential is different from "center" differential. The Wikipedia and How Stuff Works articles refer to the axle differential.

CDL puts 50% of power (or whatever you call it) to the front axle and 50% to the back axle.

 

[keepitwildtv]

Thank you Rob. I think someone thinking wheels here, but it's the center diff and not the front or rear.

I was using what would be seen at the wheels to show what happens.

 

[keepitwildtv]

NO!!!!!!!

If you lift only the front wheels and LOCK the center diff you WILL jump off the jackstands!

An open center diff only does 50/50 with perfect traction AND when you're driving in a straight line. Lift one wheel with the fenter diff open and only the lifted wheel will spin. DO NOT DO THIS WITH A RANGE ROVER WITH A VC. It too will jump off the stands because the VC will "lock" when the fluid firms up.

Daniel

 

[p m]

Put jack stands with wheels on the bottom under the axle so the front tires are off the ground. Lock the center diff. Now put it in drive and step on the gas. 100% of the engine torque will be absorbed by the rear axle and the truck will accelerate.

It sure will. Take your tiime to dig the jackstands from under the truck afterwards :rofl:

 

[gmookher]

http://auto.howstuffworks.com/differential3.htm

"The open differential always applies the same amount of torque to each wheel."

this thread just got retarded, I'm sorry.

 

[derrickalda]

this thread just got retarded, I'm sorry.

haha x2

 

[R_Lefebvre]

Why? Because the tech has devolved to the point we need to use howstuffworks as reference material? I kinda agree, and I'm not sure why I'm bothering.

 

[Mongo]

retarted is a understatement...

holy shit, I'm agreeing with Gem

 

[gmookher]

retarted is a understatement...

holy shit, I'm agreeing with Gem

haha april fools huh...