What's the consensus on.........

Quote:

---

Originally Posted by vnx205

It would appear that the answer to Tank's question is that there is no consensus.

I wonder if some of the difference of opinion results from many of us having different conditions in mind.

I notice that you said, "as soon as I am in the bush". That sounds like something quite different from what I pictured when I read the question.

I had in mind the sort of surface that Mum's shopping trolley would handle with ease. I was thinking of a perfectly smooth, firm dirt surface, the sort of surface where the CDL takes a long time to disengage after you move the lever. Rather than pull up and reverse, I often continue on and run a couple of wheels out into the loose gravel on the edge of the road.

I wouldn't expect the CDL to provide any benefit at all on such a surface.

---

Allan, reason I posed the question was I was thinking back to when Ranga done his clutch centre in on the trip to Postmans, his symptoms sounded familiar. I was speaking to a couple of blokes (LR nuts) a few years back and some of the problems they had had (with manual boxes and clutches), one of the blokes said he believed it was because of NOT engaging the CDL when on dirt/gravel roads.
I asked Ranga if he was driving with the CDL locked when he lost his clutch and he said it wasn't locked, which made me think of the conversation with these other blokes previously.
Without the CDL locked on a dirt road, even a good one (like little Sugarloaf) you will get wheel slip, not much but it is still there. With the CDL unlocked the CD is sending power to where it is needed such as wheel slip, or to the back axle when cornering.
Now on Little Sugarloaf for instance there would be hundreds (or even more) of corners so the CD is disconnecting the front axle and sending power to the rear and when on the straight away it connects back to both front and rear so the CD is working all the time and that's not counting the number of times either the front or rear axle slips on the dirt.
With the CD locked power is distributed equally to both axles and is not transferring power through the sun gears, on and off continually as when unlocked. Actual 4WD when cornering is much better than 2WD through corners, whether on dirt or tarmac, just ask Porsche or Lambo owners.
The Land Rover Owners Handbook says to engage the CDL when leaving the tarmac and on to dirt/gravel roads, there has to be less wear and tear on the CD sun gears and thrust washers when the CD is locked, Regards Frank.

CDL on gravel roads won't cause or prevent clutch failure.

Hi,

Interesting this crops up from time to time:

http://www.aulro.com/afvb/general-ch...-out-dirt.html

Frank's earlier comments re: D1 owner's manual CDL instructions for use are somewhat different from a 74 RRC.

The instruction plaque under the heater controls in my 74 is very clear in stating that the CDL should only be used when traction is lost at one or more wheels and should be disengaged immediately traction is regained.

It also says that wide throttle openings should not be used in 1st or 2nd low range with the CDL engaged to avoid unnecessary wear and possible damage.

Cheers, DL

Quote:

---

Originally Posted by 350RRC

The instruction plaque under the heater controls in my 74 is very clear in stating that the CDL should only be used when traction is lost at one or more wheels and should be disengaged immediately traction is regained.

It also says that wide throttle openings should not be used in 1st or 2nd low range with the CDL engaged to avoid unnecessary wear and possible damage.

Cheers, DL

---

The instruction plate in my 85 says to avoid wide throttle openings in low range first and second gear. But doesn't refer to the CDL in that same sentence or mention wear/damage.

The use of CDL in any gear on loose surfaces enhances handling (it's the same effect as engaging 4WD with locked hubs in, in a non-centre diff (eg. older type Jap) 4WD vehicle)

What you say may be correct with loose surfaces and since I am familiar with the road Tank is talking about, I can see some reasons to engage the CDL on that particular road.

However, I remain to be convinced that the CDL should be engaged every time you leave the bitumen. I know that a lot of dirt roads have significantly reduced traction. I have heard that the WA roads with pea gravel or whatever it is called, are diabolical.

Maybe I am misunderstanding some people's comments but it sounds as if their argument is that any dirt road needs the CDL engaged.

The reason I wonder about that approach is that I have driven on dirt roads that I swear had as much traction as some bitumen I have driven on, especially once the bitumen gets a bit of oil and/or moisture.

When I was racing motorcycles on short circuit tracks, there were some old, established tracks where the surface was so hard packed and polished that I could hear my rear tyre squealing as I came into the corners. I bet some bitumen has less grip than that. I bet that if I drove on a surface like that with the CDL engaged, that it would take forever to disengage when I moved the lever back.

I hope that when people say that the CDL should be engaged whenever you leave the bitumen, that they are not thinking of that sort of surface. I said much earlier that if the surface is such that the CDL won't disengage, then surely there is no need for the CDL to be locked. If it won't disengage as you continue to drive, surely that is proof that there is no slippage at all. In which case, how is it different from driving on bitumen?

I worry that blanket statements like, "I engage the CDL every time I am on a dirt road", are open to misunderstanding. I wouldn't like to think that some novice reading the comment would assume that it means that the CDL should be locked even if the dirt provides the same sort of grip as a bitumen road.

Quote:

---

Originally Posted by vnx205

Maybe I am misunderstanding some people's comments but it sounds as if their argument is that any dirt road needs the CDL engaged.

---

What I suspect we're seeing is more regional variation in dirt roads than anything else.
Those that drive on loose surface dirt roads more than likely lock it up. Those that drive on high traction dirt roads likely don't.

I get all types. The public dirt roads are gravelled and normally very loose where locking up the CDL gives far better directional stabililty. But occasionally in winter when they're carrying more moisture they can compact to a smooth and firm surface with plenty of traction.
The private dirt roads are usually hard and dry. Little gravel and normally good traction until they get steep.

As you know, if you've got ample traction, there is nothing to be gained by locking it.

Quote:

---

Originally Posted by 350RRC

Hi,

Interesting this crops up from time to time:

http://www.aulro.com/afvb/general-ch...-out-dirt.html

Frank's earlier comments re: D1 owner's manual CDL instructions for use are somewhat different from a 74 RRC.

The instruction plaque under the heater controls in my 74 is very clear in stating that the CDL should only be used when traction is lost at one or more wheels and should be disengaged immediately traction is regained.

It also says that wide throttle openings should not be used in 1st or 2nd low range with the CDL engaged to avoid unnecessary wear and possible damage.

Cheers, DL

---

I was told by a reliable source that they had to change the plaque due to people burning up the centre diff from not engaging it until traction was lost, ie the vehicle now not moving.

As to the amount of traction difference between even a good hard dirt/gravel road and a bitumen road, the easy way to check is accelerate up to 60k's or so and jump on the brakes and see how long/far it takes to stop, then try the same on a Tarmac lined road.
There is not a dirt road that has the same level of grip as a tarred road, and whether you can feel or sense whether your wheels are slipping or not, an unlocked CD is going to work harder on dirt that it does on tar. The reason Allan for the diff winding up is because with the CDL engaged one axle (front or rear) may slip while the other isn't slipping.
It is natural for there to be some windup, which can be alleviated, as you know, by backing up a bit.
And as for Dougals sweeping statement "CDL on gravel roads won't cause or prevent clutch failure."
Please enlighten us how you KNOW this, seeing as I did NOT say this was the case, Regards Frank

The simple answer for me and i guess the logical few is , When on a dirt , gravel road one can not guarantee the traction adhesion to be the same ect 1 metre to the next metre or even whats around the corner so with caution in hand cdl ;)
In my opinion i feel the car handles better and responds better with the cdl locked on dirt roads each to their own