| Author | Message | ||
     Damien Vrontisis (Dvrontisis) Member Username: Dvrontisis Post Number: 203 Registered: 04-2003 |
i read a lot about rover owners buying locking differentials. dont disco's come stock with locking diffs? mine locks. also, all disco's are permanent 4 wheel drive correct? | ||
| Leslie N. Bright (Leslie) Dweb Lounge Member Username: Leslie Post Number: 2434 Registered: 02-2002 |
Series 1 Discoveries have a Center Locking Differential (CDL). This is in the transfer case. The stock axle diffs are open, they do not lock. Let's start with a rear-wheel-drive car. Power from the engine passes through the transmission, through the driveshaft, to the rear axle differential, which splits the power to either side of the axle. A "four-wheel-drive" vehicle adds a transfer case behind the transmission, which splits the power so that it can go to a front differential, which can then split that power to either of the front wheels. A Jeep, or a Series Rover, or many (most?) other 4x4s have a transfer case that works like this: the transfer case will leave the drivesaft going forward in idle, allowing the power to go the rear axle. When you engage the 4x4 lever, the transfer case locks, splitting the power, sending it to both axles. In a Disco, a differential inside the transfer case acts like the axle differential, in that you don't disengage the front driveshaft, but instead, the center differential can allow the power to go to either axle. Thus, any wheel on a Disco can receive power at any time, but possibly, only one wheel, depending on how the diffs are reacting to traction. When you lock the CDL, you guarantee that some power is going to the front axle, and some to the back. That way, at least one wheel on each axle is working. By adding a locking differential in the rear diff, for example, the power that is sent to the rear axle is split, and both wheels WILL receive power. In conjunction with a CDL, 3 wheels WILL turn. A G-wagen and some Toyotas, and the Rubicon, can lock the transfer case and both the front and rear axles so that all four wheels do turn. From the factory, a Disco doesn't. DIIs use ETC, ie, a "sophisticated" use of the ABS system to stop wheels from spinning, forcing power across the diff to the other side of the axle, imitating a locking diff. It works, but has dissadvantages. Does that help? -L | ||
| June H. Han (Junehhan) Member Username: Junehhan Post Number: 52 Registered: 04-2003 |
Okay, I have an 03 Disco, so here is my question. Since the center differential is open, along with an open front and rear diff, does that mean that power is only being sent to one single wheel at any given instance in time, while the 4ETC constantly shifts it around? If that's the case, it doesn't sound like a good setup and makes me want to find a way to swap out the center transfer box for the one they use in those European 03 Disco's......... | ||
| Eric Olsen (Eric_olsen) Member Username: Eric_olsen Post Number: 51 Registered: 02-2003 |
The ETC will take you more places than you think. There is a price, IMO it will tear up your spider gears if used regularly. Eric 2000 DII (On third rear diff) | ||
| Dean Brown (Deanbrown3d) Senior Member Username: Deanbrown3d Post Number: 688 Registered: 02-2002 |
June, The etc doesn't constantly work. It only works when there is a big differential (pun not intended) in speed between the 4 wheels. And anyway, a diff doesn't only allow torque on one side at a time, it smoothly applies to both sides. Why do you think it doesn't? | ||
| Al Oliveira (Offroaddisco) Senior Member Username: Offroaddisco Post Number: 1443 Registered: 04-2002 |
June, you're right. It's not a good setup and that's why LR is going back to a CDL as an option in some markets. And you don't need to get a transfer case from a EU Disco. Just look for an LT230SE from a 1999-2000 and some 2001 Disco2's. If it's a 2001 make sure it has the CDL nipple. Everyone I've talked to with a D2 has told me how they don't really need a CDL but everyone one else with a D2 who added a CDL will say it's a must have. I'm with the group that will say if you don't have one and use your vehicle off road even in the mildest trails to make the switch. In fact I would say it's the first upgrade you should make. | ||
| ed petrush (Exp) Member Username: Exp Post Number: 59 Registered: 08-2002 |
http://auto.howstuffworks.com/four-wheel-drive.htm Here is a great write up as to how differentials work... lots of good stuff there in general for the mechanical novices. | ||
| Damien Vrontisis (Dvrontisis) Member Username: Dvrontisis Post Number: 204 Registered: 04-2003 |
but they're all stock perm 4 wheel drive correct? | ||
| Brent (Silly_me) New Member Username: Silly_me Post Number: 39 Registered: 07-2003 |
>>>but they're all stock perm 4 wheel drive correct?<<< Yeah, but without LSD or F/R diff locker the power will go to the wheel slipping rather than the wheel with the most traction. | ||
| Jaime Crusellas (Jaime) Member Username: Jaime Post Number: 67 Registered: 05-2003 |
I have a D1, but I'll throw in my 2 cents worth. I went offroad in the Pine barrens the last 2 Sundays with Dean (DII) and Peter (D1). Both their trucks are lifted 2" with mud terrains. Peter, however also has a rear locker. The trails we took were basically sand, water, and mud. And while I didn't count how many times each got stuck, it certainly didn't seem that Dean got stuck more than Peter. The one place where Peter's truck did show its capabilities though was when he drove over a dead tree about a foot in diameter (several times) that was across the water in order to break it to clear a path for the rest of us. He then proceeded to drag a 10 ft long piece of the tree along the water until he hit dry land....Wish I had it on film! | ||
| Dean Brown (Deanbrown3d) Senior Member Username: Deanbrown3d Post Number: 689 Registered: 02-2002 |
Jaime, Well I think Peter was actively trying to get stuck at some point. What he said anyway  | ||
| Chris Browne (Chris_browne) Senior Member Username: Chris_browne Post Number: 263 Registered: 02-2003 |
Darren: D1s are all wheel drive until you lock the center diff and then they become four wheel drive. D2s in the USA are not officially available with center diff lock and rely on Traction control. Rest of the World can order the center diff lock...2004 D2s in USA will reported have CDL installed. 1999-2000 d2s can have CDL retrofitted....LR never installed the connection... |
