Centre Diff Lock

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Originally Posted by Loubrey

I currently drive a Puma 90 and we have roads here known as "rail access roads" with a speed limit of 80km/h which everybody including the road trains travel at. I never engage the diff lock for these journeys and I never hear a peep out of the TC, which to me indicates I do not at any point suffer traction loss on any individual wheel.

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You generally won't get a 'peep' out of TC in those scenarios. (Otherwise known as "Talent Control" - When you run out of driving talent, the car takes control... ;))

Wheelspin is caused by excessive torque. If you're cruising at 80km/h, you're generally not giving it bootfulls of torque.

On top of that, together with the "As slow as possible, as fast as necessary" you are also taught the there is a balance between "Traction vs Momentum". At 80km/h you have plenty of momentum, so therefore you don't need much traction...

However, if you dropped it a cog or two and gunned the throttle on a bend... ;)

Yes, you can argue that you don't need to engage diff-lock until you need it but it's one of those things where it's easier to have it engaged for those times when you don't expect that you need it. It doesn't do any harm and it could make your life easier!

It's like HDC on the other cars, although you don't need it climbing a hill, it's good to have it pre-engaged as it is one less thing to have to fiddle with, if you fail the climb and are now coming down the hill backwards!!

...or turning off DSC...

etc...

M

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Originally Posted by Loubrey

As I said in my previous e-mail that's the way I've been taught and after close on a million km's travelling in Land Rovers building roads all over the world I'm still to loose a Land Rover transfer case or gearbox.

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You & me both darlin'...

In this thread, I've not been talking about mechanical sympathy, just purely about technique.

M

Quote:

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Originally Posted by Loubrey

I currently drive a Puma 90 and we have roads here known as "rail access roads" with a speed limit of 80km/h which everybody including the road trains travel at. I never engage the diff lock for these journeys and I never hear a peep out of the TC, which to me indicates I do not at any point suffer traction loss on any individual wheel.

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Conversely, down in the south west while driving on "pea gravel" at high speeds, the 110 handles much nicer and feels much safer with the CDL engaged.

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Originally Posted by isuzurover

Conversely, down in the south west while driving on "pea gravel" at high speeds, the 110 handles much nicer and feels much safer with the CDL engaged.

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Agree 100% with you about the pea gravel. Even with the CDL engaged the stuff is likely to give you the odd bout of sweats! I've only travelled that area on holidays and never in a rush. I take my hat off to you guys travelling any sort of speed on it...

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Originally Posted by Loubrey

Agree 100% with you about the pea gravel. Even with the CDL engaged the stuff is likely to give you the odd bout of sweats! I've only travelled that area on holidays and never in a rush. I take my hat off to you guys travelling any sort of speed on it...

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My first experience of driving on it was just after moving to WA - driving a hired hyundai accent (not allowed to go offroad) - out to watch the WRC on freshly graded roads (heaps of loose pea gravel). A slight blip of the accelerator and the front end would slide all over the place.

I take my hats off to the WRC drivers!!!

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You generally won't get a 'peep' out of TC in those scenarios. (Otherwise known as "Talent Control" - When you run out of driving talent, the car takes control... )

Wheelspin is caused by excessive torque. If you're cruising at 80km/h, you're generally not giving it bootfulls of torque.

On top of that, together with the "As slow as possible, as fast as necessary" you are also taught the there is a balance between "Traction vs Momentum". At 80km/h you have plenty of momentum, so therefore you don't need much traction...

However, if you dropped it a cog or two and gunned the throttle on a bend...

Yes, you can argue that you don't need to engage diff-lock until you need it but it's one of those things where it's easier to have it engaged for those times when you don't expect that you need it. It doesn't do any harm and it could make your life easier!

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Sorry For the late reply but in my Quick Start Guide it clearly states "Do not use CDL if travelling above 60km/h.

I would probably leave cdl open until you cant maintain forward movement effortlessly.

Safe off-road driving technique is to ALWAYS have centre diff locked in high range and stick to 90km/h or as close to as you safely can.

Quick start is just that... how not to damage your car and cause warranty issues when you start out driving Defenders. To wait until you can't maintain forward movement would be way to late on rough terrain or on you roof having slid off on a pea gravel bend.

My first 90 did around 320,000km before it was sold on and at least a third of that would have been at cruising speed in high range with the diff locked.

I don't like changing the transfer box on the move, but some guys on here has got the technique down pat. Again, stopping and selecting CDL only once you've lost momentum and traction is definitely not the way its done...

IMO not having Land Rover Experience in Australia is a serious drawback to the safe and effective operation of Defenders.

Cheers,

Lou

I'm surprised how many people drive around with their centre diff locked. I'd be worried I'd hit a piece of high traction surface and wind it up (more likely with me, forget to unlock it when I get on bitumin). I treat it like the rear Maxidrive, only lock it before I need it, then unlock again after we're through the soft or broken patch. Both lock and unlock on the move, just lift off throttle, flick lever, the spring pushes the locking dog clutch into engagement when the teeth lign up and unlocks when the load is off the teeth. I don't drive around on dirt roads with the maxidrive locked for fear I might spin a wheel.:D

Traction control does not assist in high speed dirt...anti slew would but deefers and d2 etc dont have that. Locking the CD on high speed dirt makes handling more positive...feels much better.

Cheers

Both my d1 a d d2 manuals dont say anything about not traveling with cd engaged above a certain spees...in fact they say you can lock on the move at any speed. I have shifted to lock many times at 90 plus.

Cheers