ucfmethod
2/28/2008 11:30:52 AM
I just bought my first Land Rover 3 weeks ago, and I have been enjoying it tremendously. I have a quick question, and I am looking for advice.
[Please do not attack me, this is an honest question and asinine remarks will be ignored]
When should I lock the differential? I am not a off-road gear head, so I have never had a vehicle with a locking diff. I find that low gear gets me through anything I need to climb over or when driving in snow. I assume that when I move the gearbox to locking position (slide it left) it will make all the wheels spin at the same speed ALL the time. Is this wise? I probably will never go rock climbing for fear of rolling this baby, but heavy snow will likely occur frequently. What scenarios do you guys have for when I should lock the diff?
Thanks in advance.
-Von
jdelp
2/28/2008 11:40:05 AM
I don't live far from you, just north in baltimore. Frankly, for the amount of snow that we get and for the type of driving that you'll do, you'll never need your diff lock. If you never go off road, at least engage your t-case to low gear and diff lock every few months so that it doesn't seize up. As far as use, I lock the transfer case in high (just slide to the left) for deep snow or sand driving. Low gear and diff locked only for very deep mud or rock crawling where you're under 5mph. Your truck is AWD all the time so other than excercising the lever you probably won't need it unless we get a big Noreaster or a blizzard.
ucfmethod
2/28/2008 11:54:14 AM
thanks. I will start doing that monthly...
side note, since you have the same Disco as me, what ski/roof racks did you find (if any) that fit those large round bars we have?
thx
Von
jdelp
2/28/2008 12:08:32 PM
99XJ
2/28/2008 12:32:15 PM
I use Thule 450 mounts with 50" crossbars. I can transfer it between my '03 and my wife's '06 outback. Rack goes on and off in less than 5 minutes, so I only put on when skiing so i don't lose anymore mpg's when driving around town. It was a no brainer for me since I've been using Thule for over 20 years.
With this mount system I can load my skis stacked together and the bindings have enough clearance not to hit the roof.
I were to purchase again, I'd get longer crossbars (if they were only going on Discovery, but they wouldn't have worked with the Subie).
Disco Mike
2/28/2008 12:37:24 PM
Von,
What year is your truck?
ucfmethod
2/28/2008 12:59:39 PM
2004 with 35k miles on it.
As an aside, don't lock your case when you're driving over ice.
Disco Mike
2/28/2008 1:14:53 PM
Why, I do all the time, here in Colorado, help alot.
Other wise, locking the CDL is designed to give you alot more traction in snow, mud,sand, and off the road.
Go for it.
Disco2Guy
2/28/2008 1:33:26 PM
quote:
ORIGINAL: ucfmethod
...it will make all the wheels spin at the same speed ALL the time.
Please correct me if I'm wrong, but doesn't the CDL transfer equal power (50/50) to the front and rear axles? You would need something like ARB lockers to get all the wheels moving at the same speed all the time. You also have the option to engage the CDL before starting the engine which will turn off the T/C and ABS. Engage it while running and you will have T/C and ABS as usual.
What happens if T/C off (CDL engaged) and a tire is off the ground, what happens to the power? Does more power go to the tire with traction on the ground for the same axle?
S4poor
2/28/2008 2:01:26 PM
quote:
ORIGINAL: 99XJ
I use Thule 450 mounts with 50" crossbars. I can transfer it between my '03 and my wife's '06 outback. Rack goes on and off in less than 5 minutes, so I only put on when skiing so i don't lose anymore mpg's when driving around town. It was a no brainer for me since I've been using Thule for over 20 years.
With this mount system I can load my skis stacked together and the bindings have enough clearance not to hit the roof.
I were to purchase again, I'd get longer crossbars (if they were only going on Discovery, but they wouldn't have worked with the Subie).
2nd. I have the same exact setup. The best deal going IMHO.
S4poor
2/28/2008 2:05:44 PM
quote:
ORIGINAL: Disco Mike
Why, I do all the time, here in Colorado, help alot.
Other wise, locking the CDL is designed to give you alot more traction in snow, mud,sand, and off the road.
Go for it.
When are you free to meet up Mike?
ucfmethod
2/28/2008 2:11:31 PM
quote:
Please correct me if I'm wrong, but doesn't the CDL transfer equal power (50/50) to the front and rear axles? You would need something like ARB lockers to get all the wheels moving at the same speed all the time. You also have the option to engage the CDL before starting the engine which will turn off the T/C and ABS. Engage it while running and you will have T/C and ABS as usual.
What happens if T/C off (CDL engaged) and a tire is off the ground, what happens to the power? Does more power go to the tire with traction on the ground for the same axle?
I like where this is going. None of these I have ever heard of, and of course the salesmen at the dealership mentioned none of these when selling me the car ;-)
Can anyone elaborate on any of this?
ucfmethod
2/28/2008 2:25:41 PM
quote:
I use Thule 450 mounts with 50" crossbars. I can transfer it between my '03 and my wife's '06 outback. Rack goes on and off in less than 5 minutes, so I only put on when skiing so i don't lose anymore mpg's when driving around town. It was a no brainer for me since I've been using Thule for over 20 years.
And those Thule's fit around the big round OEM bars on the 2004 models? If so, then I will buy them tomorrow ;-)
S4poor
2/28/2008 2:27:00 PM
quote:
ORIGINAL: ucfmethod
quote:
Please correct me if I'm wrong, but doesn't the CDL transfer equal power (50/50) to the front and rear axles? You would need something like ARB lockers to get all the wheels moving at the same speed all the time. You also have the option to engage the CDL before starting the engine which will turn off the T/C and ABS. Engage it while running and you will have T/C and ABS as usual.
What happens if T/C off (CDL engaged) and a tire is off the ground, what happens to the power? Does more power go to the tire with traction on the ground for the same axle?
I like where this is going. None of these I have ever heard of, and of course the salesmen at the dealership mentioned none of these when selling me the car ;-)
Can anyone elaborate on any of this?
Four wheel drive systems
Manual 100% Differential Lock Differential lock, diff locks, lockers are not the same as a locking differential
Typical manual differential lock (Unimog) 
Differential locks (when engaged properly) guarantee equal wheel speed on all 4 wheels. Spinning wheels are prevented.
Heavy duty off-road situations ask for three (center differential & front and rear axle differentials) manually and independently lockable differentials. Dog clutches provide the lock up.
They require a trained and experienced driver to operate them properly. Untrained use may cause more harm than good. Improper use on pavement may cause death or injury. Improper use off-road may cause component failure or severe difficulties to maneuver the truck.
Ideally, differentials should be (manually) locked
before traction is lost and wheels start spinning.They need to be switched off immediately after passing through a tough off-road section.
Here is how to best use a manual locker.
4WD and
differential locks should be used to
prevent getting stuck - they might not work to get you out of stuck situations.
Here is how the inside of a differential looks like *Warning: motor sports and 4WD activities are potentially dangerous. The information listed in this web site does not hold its author or representatives liable for any damage or injuries sustained.
Only few vehicles in the US are offered stock with front and rear differential locks: Dodge Powerwagon, Jeep Wrangler Rubicon, Mercedes G500.
On some models a rear differential lock is optional: Porsche Cayenne, VW Touareg, some Mitsubishi, some Toyota, Hummer H2, Hummer H3.
Other terms used for differential locks are: locker, diff locks, diff lockers, differential lockers
Unfortunately, limited slip differentials (LS), available as options for many 4x4 in the US are offered by sales people as "locking differentials". A confusing term because nothing on these differentials is LOCKING. They are by far inferior to a differential that is truly (manually or automatically) lockable.
If you have to decide whether to get a "locking differential" aka limited slip (LS), if available as an option on your new truck, I would recommend getting it, because it is still better than not having anything at all.
To repeat: "locking differentials" are limited slip differentials that are not to be confused with differential lock!
Differential lock = differential locker = diff lock = diff locker = locker
It seems to me, that manufacturers and dealers prefer to use the term "locking differential" over the correct term "limited slip differential" because it sounds more like the real thing - even though it is not. Is this already consumer fraud?
Now here is a twist to the locking differential story: When Chevy advertises its trucks with an optional rear locking differential - it indeed is a differential that locks up (automatically). In the 80's it was sold as a Gov-Lok for a while named Command-Traxx and is available in some Chevy trucks as G80 option. It is not manually activated as in Dodge, Jeep and Mercedes - it locks up automatically. It is a hybrid of a clutch type limited slip unit combined with a flyweight governor that is able to lock up 100%.
In addition to factory installed diff locks, there are several aftermarket options to add a differential lock to front and rear axles. ARB Air Locker, Detroit Locker, Eaton Locker are probably the best known. Recently we saw some newcomers like the OX Locker which seems like a copy of a long know German Schwarz locker to me.
ucfmethod
2/28/2008 2:37:31 PM
Um.. so what does my trusty Land Rover Disco 2004 SE have?
Disco Mike
2/28/2008 2:44:44 PM
You have a t/case that you can lock up and you have ETC so when your CDL is engaged, the ETC can then power back and forth from the left side to the right side of each diff as needed.
Disco Mike
2/28/2008 2:48:12 PM
quote:
ORIGINAL: Disco2Guy
quote:
ORIGINAL: ucfmethod
...it will make all the wheels spin at the same speed ALL the time.
Please correct me if I'm wrong, but doesn't the CDL transfer equal power (50/50) to the front and rear axles? You would need something like ARB lockers to get all the wheels moving at the same speed all the time. You also have the option to engage the CDL before starting the engine which will turn off the T/C and ABS. Engage it while running and you will have T/C and ABS as usual.
What happens if T/C off (CDL engaged) and a tire is off the ground, what happens to the power? Does more power go to the tire with traction on the ground for the same axle?
Yes 50% to each diff, but because you have open diffs, you will only have power initially to the right rear and the left front tires equally. Now if the ETC kicks in, it may shift that power to the other wheel on either diff.
You woull need lockers in both diffs to in fact have full 4 wheel traction.
Disco Mike
2/28/2008 2:49:27 PM
quote:
ORIGINAL: S4poor
quote:
ORIGINAL: Disco Mike
Why, I do all the time, here in Colorado, help alot.
Other wise, locking the CDL is designed to give you alot more traction in snow, mud,sand, and off the road.
Go for it.
When are you free to meet up Mike?
You want to go play in the snow??
jkid
2/28/2008 3:16:53 PM
quote:
ORIGINAL: S4poor
quote:
ORIGINAL: jmt
As an aside, don't lock your case when you're driving over ice.
That makes zero sense. Care to elaborate?
Maybe he meant differential? That would make more sense.
BADBUZzZzZz
2/28/2008 7:19:50 PM
quote:
ORIGINAL: Disco Mike
You have a t/case that you can lock up and you have ETC so when your CDL is engaged, the ETC can then power back and forth from the left side to the right side of each diff as needed.
Wow so I thought thats what my 03 disco did? So mine will and can transfer all the power to just the rear or front becouse I dont have CDL?
okdiscoguy
2/28/2008 7:22:24 PM
YOur ETC works on all four wheels, but with the CDL, it doesn't have to think between front and rear. It would only have to work at 2 wheels, vs 3 wheels without CDL.
Disco Mike
2/29/2008 7:07:54 AM
I agree totally with the last 2 posts.
For the 03, the good news is that that year had an updated ETC over the earlier models and performs much better off road.
jdelp
2/29/2008 7:34:53 AM
And I would agree w/ the last 3 :) I was skeptical being a previous jeep owner, had upgraded axles, diffs and air-lockers w/ 2 inch lift. I thought that thing was invincible. Just to test the ETC on my '04 I sat it in about 6-8 inches of mud, took it out of low gear and disengaged the CDL. ETC made it's usual pops and buzzes and she climbed right out. Since then I'm a believer.
