Numpties guide to 4x4

Paul Baker

New Member
I am in uk
May 2, 2018
24
6
3
Worksop
ok ..so here goes...

my LC5 has allsorts of 4x4 toys :)

traction control
DAC
4x4 hi/low
lockable diff switch !! etc etc

do i know how to use them ? NOPE :)

was just wondering if anyone can give a basic "whats this and how/when to use" for these new toys ........before i go and bust em ! ;)

regards
 

stumog

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I am in england
Oct 3, 2012
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Hi Paul

It may help if you went out with someone that has experience of them before you go off on your own.

If your in the south west happy to take you through it
 

Paul Baker

New Member
I am in uk
May 2, 2018
24
6
3
Worksop
thanks mate but up nottingham way ..i was just wondering about reading how users use them rather than trying to undserstand what the manual tries to tell me :) not that i chuck her down country lanes often, but would just like to know what to press if i ever did ;)
 

Shayne

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If your stuck use low , and if your still stuck lock the diff , unless like many of us do you go out looking for ways in which to test your vehicles ability in extreme circumstance your unlikely to need either .

Using them when you don't need to is asking for trouble .
 
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Higgy

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I pushed the 4x4 switch by mistake while fumbling for the drivers heated seat switch, It made the dashboard interesting for a while at 50mph.. Till i realised what id done.. Try it sometime!
 

moggy1968

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Jun 12, 2013
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Youtube is your friend these days, 4xoverland has some good how to videos, as does Ronnie Dahl.
Only lock the diff in slippery conditions, i.e. off road. Using the diff lock on tarmac will shag your transmission.
I'll try and give a brief explanation of how the difflock works.
When a vehicle goes round a bend, the inside wheels describe a different arc to the outside wheels.
to get around that, a rear wheel drive has a differential, this allows the wheels to travel at different sspeeds. An unfortunate side effect of this though is that if one wheel starts to spin, all the power is transmitted to the spinning wheel, so you get stuck.
Here's a video

Also, the front and rear wheels describe a different radius of curvature. This is of course not a problem in a 2 wheel drive vehicle. However, in a fulltime four wheel drive (4WD) like yoours that would be an issue because the front and rear axles would be trying to travel at the same speed. In a part time 4wd this is overcome by using a lever, or hydraulics, to mechanically disconnect the front and rear drive, so power only goes to the rear axle unless 4wd is engaged.

In a fulltime 4wd like yours the solution is to fit a differential (a bit like the one in the axle described above) between the front and rear axles. This effectively locks the 2 axles together, which is why you musn't use it on a grippy surface. It is a common schoolboy error to think that to get a fulltime 4wd stuck, you need all four wheels to be spinning, this is not the case. As we can see from the above, without the differential locked you would only need one wheel spinning, either a front or a rear. If you lock the centre diff, then you would need a front and a rear wheel spinning to get stuck (most often seen in a situation called being 'cross axled')
The traditional way around this was to fit locking differentials to the rear, and sometimes the front, axles (when a vehicle has front rear and centre locking differentials fitted it is often referred to as 'triple locked'). This would ensure that in order to be stuck through loss of traction, all four wheels would have to be spinning.
A more modern solution to this is to use the traction control system to send power to the wheel with grip by utilising the ABS. It's a bit like the old school solution which was to lightly apply the footbrake so there was some resistance on the spinning wheel and some power would go to the other wheel. Arguably these electronic systems don't work as well as proper locking diffs, but they vary widely between vehicles and can be very good.

I would disagree with the above comments. Do not wait until you are stuck! read the terrain ahead and select the appropriate vehicle setup for what is coming up. If you wait until you are stuck the vehicle and tyres have to work that much harder to get you unstuck rather than powering through, and that maybe the difference between getting through or not. I often engage my rear difflock when I probably don't need it, because why wouldn't you? I would rather have more traction than less. Just don't do it where there is a lot of grip.

using difflocks on a hard surface leads to a condition called transmision wind up. As we have seen above, having a diff locked means a particula set of wheels will travel at the same speed, when you turn a corner the wheels need to travel at different speeds, but locking the diff means they are trying to travel at the same speed. This isn't a problem on a loose surface, the extra rotation just spins out through the wheels, but if you are in high grip, say on tarmac (even wet tarmac, or even hard packed dirt) the wheels can't spin it out and it will put a big strain on your transmission, eventually leading to failure somewhere in the drivetrain.

Another video!

In terms of high and low range, low range is just a reduction gearbox so you will go considerably slower in a given gear for a given amount of revs. There are a number of advantages to this, such as better control off road,being able to go slowly without riding the clutch, control on steep ascents and decents (which can be extremely dangerous if you don't know what you're doing so research this before it happens) and in terms of the amount of 'torque' available. It doesn't actually increase torque but I can't think of a better way to describe it but lower gears equals more pulling ability.

You might also find this video useful


Crawl control is a new fangled feature
Heres another vid!!!
 
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Paul Baker

New Member
I am in uk
May 2, 2018
24
6
3
Worksop
Youtube is your friend these days, 4xoverland has some good how to videos, as does Ronnie Dahl.
Only lock the diff in slippery conditions, i.e. off road. Using the diff lock on tarmac will shag your transmission.
I'll try and give a brief explanation of how the difflock works.
When a vehicle goes round a bend, the inside wheels describe a different arc to the outside wheels.
to get around that, a rear wheel drive has a differential, this allows the wheels to travel at different sspeeds. An unfortunate side effect of this though is that if one wheel starts to spin, all the power is transmitted to the spinning wheel, so you get stuck.
Here's a video

Also, the front and rear wheels describe a different radius of curvature. This is of course not a problem in a 2 wheel drive vehicle. However, in a fulltime four wheel drive (4WD) like yoours that would be an issue because the front and rear axles would be trying to travel at the same speed. In a part time 4wd this is overcome by using a lever, or hydraulics, to mechanically disconnect the front and rear drive, so power only goes to the rear axle unless 4wd is engaged.

In a fulltime 4wd like yours the solution is to fit a differential (a bit like the one in the axle described above) between the front and rear axles. This effectively locks the 2 axles together, which is why you musn't use it on a grippy surface. It is a common schoolboy error to think that to get a fulltime 4wd stuck, you need all four wheels to be spinning, this is not the case. As we can see from the above, without the differential locked you would only need one wheel spinning, either a front or a rear. If you lock the centre diff, then you would need a front and a rear wheel spinning to get stuck (most often seen in a situation called being 'cross axled')
The traditional way around this was to fit locking differentials to the rear, and sometimes the front, axles (when a vehicle has front rear and centre locking differentials fitted it is often referred to as 'triple locked'). This would ensure that in order to be stuck through loss of traction, all four wheels would have to be spinning.
A more modern solution to this is to use the traction control system to send power to the wheel with grip by utilising the ABS. It's a bit like the old school solution which was to lightly apply the footbrake so there was some resistance on the spinning wheel and some power would go to the other wheel. Arguably these electronic systems don't work as well as proper locking diffs, but they vary widely between vehicles and can be very good.

I would disagree with the above comments. Do not wait until you are stuck! read the terrain ahead and select the appropriate vehicle setup for what is coming up. If you wait until you are stuck the vehicle and tyres have to work that much harder to get you unstuck rather than powering through, and that maybe the difference between getting through or not. I often engage my rear difflock when I probably don't need it, because why wouldn't you? I would rather have more traction than less. Just don't do it where there is a lot of grip.

using difflocks on a hard surface leads to a condition called transmision wind up. As we have seen above, having a diff locked means a particula set of wheels will travel at the same speed, when you turn a corner the wheels need to travel at different speeds, but locking the diff means they are trying to travel at the same speed. This isn't a problem on a loose surface, the extra rotation just spins out through the wheels, but if you are in high grip, say on tarmac (even wet tarmac, or even hard packed dirt) the wheels can't spin it out and it will put a big strain on your transmission, eventually leading to failure somewhere in the drivetrain.

Another video!

In terms of high and low range, low range is just a reduction gearbox so you will go considerably slower in a given gear for a given amount of revs. There are a number of advantages to this, such as better control off road,being able to go slowly without riding the clutch, control on steep ascents and decents (which can be extremely dangerous if you don't know what you're doing so research this before it happens) and in terms of the amount of 'torque' available. It doesn't actually increase torque but I can't think of a better way to describe it but lower gears equals more pulling ability.

You might also find this video useful


Crawl control is a new fangled feature
Heres another vid!!!




Moggy what a percect reply ! just what i needed many many thanks :)
 

TONYCY11

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Oct 25, 2015
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OK Then.. The switch next to the drivers heated seat switch
That's the centre diff lock switch Higgy use that only off road when stuck in mud snow etc it disengages vsc when switch on hence other lights light up when switched on , best not switch on while driving on tarmac or normal speeds or damage can be done to drive line .
 

GeekOKent

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OK Then.. The switch next to the drivers heated seat switch
The VSC ? Should be ok to leave that on, or if you like to drive your own car and leave it off - best to get that engaged sometime between when the car starts siding sideways and before contact with the wall! :)

If it's the CDL switch, I thought you had to be in low range to get that engaged. I have certainty not tried it on high on the motorway, and definitely not when already moving.
 

Chris

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The LC5 has ATRAC doesn't it? You shouldn't really need to press anything. Let it do its thing.

I'd also read the manual for this specific vehicle. You can typically engage CDL at speeds of up to 60 mph. That's normally on a sticker on the door trim IIRC. Very good to reduce aquaplaning. We've had this debate many times about CDL and things like motorway driving in the rain and sleet. The manual says 'yes'.
I didn't think the LC5 had a rear locker. Only the LC3?

Which year / model is this Paul - I presume it's a 120?
 

Higgy

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That's the centre diff lock switch Higgy use that only off road when stuck in mud snow etc it disengages vsc when switch on hence other lights light up when switched on , best not switch on while driving on tarmac or normal speeds or damage can be done to drive line .
Yes i know this Tony,, I pressed it by accident, Didnt half make the dash light up... Any way when you look at the diagram on the switch I thought it was for when you wanted to turn out of control to the right..:thumbup:
 
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GeekOKent

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The LC5 has ATRAC doesn't it? You shouldn't really need to press anything. Let it do its thing.

I'd also read the manual for this specific vehicle. You can typically engage CDL at speeds of up to 60 mph. That's normally on a sticker on the door trim IIRC. Very good to reduce aquaplaning. We've had this debate many times about CDL and things like motorway driving in the rain and sleet. The manual says 'yes'.
I didn't think the LC5 had a rear locker. Only the LC3?

Which year / model is this Paul - I presume it's a 120?
Good to know about the CDL.

For atrac, I have usually had it help most with VCS off and in low. It's done very little on the lc5 on the odd slide on tarmac. Works quite nice off tarmac!
 

Paul Baker

New Member
I am in uk
May 2, 2018
24
6
3
Worksop
ok heres the issue

my cruiser 2007 lc5 auto
so it has HNL short gear stick
the normal auto gear lever
CDL switch just in front of the other two sticks.....

now i know your not supposed to do anything on tarmac but just thought id see if cold engage the different systems and mybe move just a metre two in a straight line suggesting that wont do any damage...

heres the thing....manual says press cdl and the flashing dash light will go out when the central diff is locked......doesnt say anything about if i need the other levers in any sequence.......

so sat in car
engine running
car in d4

press cdl ...dashlight just sits and flashs and does nothing else

think ive tried every combination of levers to get the dashlight to stay light and "engaged" but all it does is sit and flash......

what am i doing wrong ?

thanks
 

AndyCook

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I am in scotland
Apr 16, 2010
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You usually need to drive forwards in a straight line a bit to get difflock components to line up and engage the difflock.
When I had a Landcruiser Colorado I often blipped the throttle and coasted a bit to get the locker to engage and disengage
 

Shayne

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Feb 2, 2013
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If it could align to lock it would do it just as soon as you flicked the switch but it can't so back and forth in a perfectly straight line wont align it either . It ain't gonna do no harm to swerve a bit (in reverse maybe) making the rear wheels turn at different speeds , at a very low speed , so the lock can spring when both wheels are where they need to be . Using the low box will likely help assuming you only wan't to test if it works .
 

TONYCY11

Well-Known Member
I am in cyprus
Oct 25, 2015
604
415
63
ok heres the issue

my cruiser 2007 lc5 auto
so it has HNL short gear stick
the normal auto gear lever
CDL switch just in front of the other two sticks.....

now i know your not supposed to do anything on tarmac but just thought id see if cold engage the different systems and mybe move just a metre two in a straight line suggesting that wont do any damage...

heres the thing....manual says press cdl and the flashing dash light will go out when the central diff is locked......doesnt say anything about if i need the other levers in any sequence.......

so sat in car
engine running
car in d4

press cdl ...dashlight just sits and flashs and does nothing else

think ive tried every combination of levers to get the dashlight to stay light and "engaged" but all it does is sit and flash......

what am i doing wrong ?

thanks
On early 120s the centre diff lock is mechanical and is in engaged with the H-L lever , yours is the later model and engaged by electric motor on the centre diff , I would be checking that the plugs and wiring are OK , and any relays fuses etc , good luck .
kind Regards
Tony
 

garygiles1963

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Dec 28, 2015
656
206
43
London
HI

I just happened to be thinking about VCS yesterday, thought I search to see if anyone could clear up a few questions, boom, here it all is.

Moggy thanks so much for taking the time to write your thoughts on it, helped answer all my questions, many thanks.

G.
 
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