Thread: CDL Advice

See the “CDL in D2’s” thread in “The Good Oil” section. All the mysteries of the CDL are revealed there.

1. So it looks like ive been driving with the CDL in the locked position since I bought it, but it hasnt been physically locked - What do people think of this. is this weird or a worry?

IMHo you have turned from unlocked to locked without realising it .

AFAIR , to lock is clockwise or the way you turned.

However it is really not possible for the lock to not engage if the bolt/selector is in the locked position.

The lock is just a big dog clutch which drops in as the dogs become aligned and is spring loaded so that it drops in as soon as the dogs align.

You would have surely noticed if it was locked in a concrete car park while turning as the tyres would have screeched their dismay.

I think that you have not damaged it as if you had it locked for long you would have broken a diff, CV joint, UJ, or rubber donut.
Regards PhilipA

The way to, and reasons to, lock the centre diff hasnt changed in twenty years,, and wont change for the next twenty,,
The threads in The Good Oil are as correct today as they were when first posted.


the D1 and D2 CDL is famous for


Use it or Lose it,,
(like most things..)

and yes they do tend to "stick" if not used regularly...

Don't drive on sealed roads with it locked.

Originally Posted by PhilipA

IMHo you have turned from unlocked to locked without realising it .

AFAIR , to lock is clockwise or the way you turned.

However it is really not possible for the lock to not engage if the bolt/selector is in the locked position.

The lock is just a big dog clutch which drops in as the dogs become aligned and is spring loaded so that it drops in as soon as the dogs align.

You would have surely noticed if it was locked in a concrete car park while turning as the tyres would have screeched their dismay.

I think that you have not damaged it as if you had it locked for long you would have broken a diff, CV joint, UJ, or rubber donut.
Regards PhilipA

Thanks mate. I definitely would have realized if it had been locked. I didnt even get out of the driveway (about 3 meters) and I said to wife I can feel the difference already. it mus be locked now.
Im not gunna stress about the mystery I guess. I probably did turn it without realising. Im just happy that I can do it and can activate tractor mode.

Originally Posted by Matg43

tractor mode.

Regarding 'Tractor mode' or ratio selector or 'hi/low' there should be a lever in the cab. You have to come to almost a complete stop to make changes. Three settings:
- high for normal road
- neutral, your vehicle wont move, used for example when using hydraulic winches
- low or 'tractor mode'.

If you are getting under the vehicle then you are activating the centre diff lock and not 'tractor mode' - just two movements, engaged or not engaged. This is a separate area in the transfercase to the 'tractor mode' thing. Centre diff lock can be activated when the ratio selector is normal road, neutral or 'tractor mode', but always on lose surfaces and on the move if you can help it.

Sometimes the dog clutches in both ratio selection and CDL have difficulty engaging, but usually a bit of back and forth with the gears moves things to alignment. Sometimes they may not disengage due to tension built up in the system, if it won't disengage going forward, then roll backward a bit.

Another thing that might be causing engagement issues is worn selector forks, responsible for pushing the dog clutch back and forth. I have a D1 with 600,000 and the forks still work fine despite some wear evident, so unlikely to be your problem.

When moving the ratio selector in the cab, or under the vehicle moving the CDL you should feel the detent bearing find home, three homes for the ratio selector and two for the CDL. If the grub screw/spring system is loose or fallen out then the detent will be vague or non existent when moving the CDL or ratio lever. You may think you have moved something, but not really far enough to get engagement, but again a remote chance of this happening. If your moving the ratio selector in the cab, you should feel three distinct positions, but sometimes the gear won't move at all or very little from the high ratio, again roll the vehicle back and forth using the gears while giving the ratio selector lever 'a go' - it's a very distinct feeling of three positions when working.

The only time you would be getting under the car to get 'tractor mode' would be if your linkage from the cab is broken. Just worried you are engaging diff lock on hard surface, getting lockup resistance and thinking it is 'tractor mode' when it isn't. Maybe I'm just misreading the thread. And a second hand linkage for the diff lock shouldn't cost a thousand dollars. I've bought whole vehicles for a couple of hundred - and before you ask, no I don't have a spare.
-

Talking crawl factors, low range in a Landy is generally lower than most other mainstream 4x4's.
It's definitely lower than a GQ or GU Patrol for example.
Off the top of my head I can only think of the Wrangler Rubicon having a lower low range in stock form?

If 'tractor mode' is more referring to front tyre scrub when in 4wd, well yep, engage the CDL if you have it, but remember that the TC in that old Disco is still very very good, and at the time was state of the art.
It took a long time for the Japanese rivals to catch up on the TC front.

Oh, and you can buy a vacuum operate CDL activation kit out of the UK for around $250 landed, or even less.
I bought a pull cable operated version for $110 but will probably get the vacuum operated one as it's neater.

Originally Posted by rick130

the TC in that old Disco is still very very good

Yep, read somewhere it is one of the best standard production units you can get with an off the shelf 4x4. Can't speak so highly for some other parts of their vehicles...

And again, lock the CDL in soft surface - just repaired one done in by previous owner - such a common breakage that the 6 gears in the CDL carrier are readily available for a couple of hundred new.

Get an Ashcroft torque biasing diff to solve these issues with the CDL breakages. Drops straight in basically.