disco_steve
New Member
ALL Disco's and range Rovers are FULL TIME four wheel drive
The older series landrovers are two wheel (rear) selectable to four wheel on the move in high range, and full time (permanent) 4 wheel in low range
The Defenders are the same as Disco's and RR's
But . . . if you want to get technical, a 4x4 is only actually a 2 wheel drive (one wheel on each axle) unless you have locable or limited slip diffs . . . a centre lockable diff ONLY locks the drive (prop) shafts between the front and rear diffs . . .
That's why a normal 2 wheel drive car will get stuck when ONE wheel spins, because they're actually only ONE wheel drive (through the differential)
The older series landrovers are two wheel (rear) selectable to four wheel on the move in high range, and full time (permanent) 4 wheel in low range
The Defenders are the same as Disco's and RR's
But . . . if you want to get technical, a 4x4 is only actually a 2 wheel drive (one wheel on each axle) unless you have locable or limited slip diffs . . . a centre lockable diff ONLY locks the drive (prop) shafts between the front and rear diffs . . .
That's why a normal 2 wheel drive car will get stuck when ONE wheel spins, because they're actually only ONE wheel drive (through the differential)
ratty
I'm not special I'm limited edition
Pikey
Dummy Ejection Facilitator..
disco_steve
New Member
They get EVERYWHERE !!!
ratty
I'm not special I'm limited edition
Aye well try ta keep up Junior.
I would say I was trying but I rekon I know yer answer
Pikey
Dummy Ejection Facilitator..
I would say I was trying but I rekon I know yer answer
Must try harder, Detention fer yu sonny boy. See me after lessons
ratty
I'm not special I'm limited edition
Must try harder, Detention fer yu sonny boy. See me after lessons
phew. I thought you wuz gonna banish me to wales
ratty
I'm not special I'm limited edition
Nah only the real bad boys get sent ter see Mr Yella.
Coor blimey govna
. Theres a lot of bad boyz n girlz in this place then.mondo
hybrid gurl
stig
sirus
raz
redhand
spuddy
simon holland
Theys all been bannished to see Mr Yella at Easter
WHAT BOLLOCKS
a diff supplies drive to both wheels on an axle, otherwise why bother having two drive shafts?
the amount of drive directed to each wheel depends on the amount of resistance offered by each wheel.
if you have one wheel in mud most , if not all, drive will go to that wheel
if you have two wheels on the same surface dunt mater if its low friction surface such as mud/ice or high friction like tarmac the diff will direct the same amount of drive to each wheel.
this bollocks about 4x4 only being two wheel drive was probably thought up by some pillock from a orf road center trying to look clevver.
off course yer got yer LSD's and diff locks that affect how the diff works but a4x4 is 4 wheel drive if you wanna be a smart arse then you could say that yer 4x4 is 4wd except in circumstaces where you lose grip at one wheel, in which case it ill be a 4x3 or one wheel on each axle then you'll have 2wd.
losing grip at both wheels on one axle will not cause you to lose yer 4wd it will however not get much propulsion from the two wheels with no grip.
now lets have less of this nonsense
disco_steve
New Member
What I said is NOT BOLLOCKS as you so kindly put it, what you have said is EXACTLY what I was saying, if ONE wheel is spinning, and you are not moving (2 wheel drive for example) then it is EFFECTIVELY A ONE WHEEL DRIVE (or NOT drive more acurately)
So in a Landy, if to are diagonal across say a ditch, with two diagonal opposite wheels that are in mid air - no diff lock or limited slip stuff, traction trickery etc and ONE wheel on EACH axle is spinning fast, and you ain't moving, then EFFECTIVELY it's a BLOODY TWO WHEEL DRIVE
(AND yer STUCK)
I KNEW what I was TRYING to explain . . . .
QUOTE:
That's why a normal 2 wheel drive car will get stuck when ONE wheel spins, because they're actually only ONE wheel drive (through the differential)
unquote
WRONG!
The whole point about an ordinary diff is that it can only apply exactly equal torque (drive) to each side, and it can allow the wheels on opposite ends of the same axle to rotate at different speeds. If the prop-shaft was turning at a rate that would give (say) 10 mph on the road, if one wheel is stopped, and the other one is spinning, the spinning one is spinning at 20 mph worth.
So if ONE wheel slips, and provides no grip, then NO torque can be used by the other wheel, and so you don't have two wheel drive, or even one wheel drive, you have NO wheel drive!
In a Disco or Defender, permanent 4x4 or not, if the centre diff is working (NOT locked) then if any ONE wheel slips and spins NONE of the other three will provide drive - the three diffs will simply "spin".
But if you lock the centre diff you force both prop shafts to turn at the same speed, with no differential action between front and rear, and any ONE wheel can slip without killing drive ON THE OTHER AXLE.
Moral: Lock the centre diff BEFORE you get stuck, and maybe you won't get stuck after all.
CharlesY
That's why a normal 2 wheel drive car will get stuck when ONE wheel spins, because they're actually only ONE wheel drive (through the differential)
unquote
WRONG!
The whole point about an ordinary diff is that it can only apply exactly equal torque (drive) to each side, and it can allow the wheels on opposite ends of the same axle to rotate at different speeds. If the prop-shaft was turning at a rate that would give (say) 10 mph on the road, if one wheel is stopped, and the other one is spinning, the spinning one is spinning at 20 mph worth.
So if ONE wheel slips, and provides no grip, then NO torque can be used by the other wheel, and so you don't have two wheel drive, or even one wheel drive, you have NO wheel drive!
In a Disco or Defender, permanent 4x4 or not, if the centre diff is working (NOT locked) then if any ONE wheel slips and spins NONE of the other three will provide drive - the three diffs will simply "spin".
But if you lock the centre diff you force both prop shafts to turn at the same speed, with no differential action between front and rear, and any ONE wheel can slip without killing drive ON THE OTHER AXLE.
Moral: Lock the centre diff BEFORE you get stuck, and maybe you won't get stuck after all.
CharlesY
Oddie
AntiSeptic Sandal Wearer
yeah but effectively and actually aren't the same thing! The fact that the mechanics and engine are trying to drive all 4 wheels makes it by definition a four wheel drive, irrespective of what is actually happening! Landys are permanent 4x4 full stop.
where does it say anything about ditches and the like in yer original bit?
so if its a two wheel drive why is it called a 4 wheel drive?
does that mean that yer average car is then demoted to one wheel drive and would a motor bike become no wheel drive as it has one less driven wheel that a one wheel drive car?
and its still bollocks oh you can twist tha facts all yer like and pretend it sensible to call a 4wd , 2 wd, but it will still be a four wheel drive except in a few circumstances where friction between tyre and surface is lost on one wheel on each axle
so if its a two wheel drive why is it called a 4 wheel drive?
does that mean that yer average car is then demoted to one wheel drive and would a motor bike become no wheel drive as it has one less driven wheel that a one wheel drive car?
and its still bollocks oh you can twist tha facts all yer like and pretend it sensible to call a 4wd , 2 wd, but it will still be a four wheel drive except in a few circumstances where friction between tyre and surface is lost on one wheel on each axle
in which circumstance, even if the centre diff is locked, it will be a NO wheel drive car!
Assuming the axle diffs are "free" diffs, and not limited slip or lockers, then it is VITAL to remember that whatever happens, BOTH TYRES will apply exactly the same grip / drive, so if one slips and thus has no grip or drive, the other one may not be spinning, but it isn't driving either.
That is a certain fact.
CharlesY
aye but are we talking about the wheels driving the vehicle or the diff supplying drive to the wheels?
the difference being whether you could have all the wheels propelling the vehicle or you might be off the opinion that because all the wheels are part of the drive train then even if the wheels are spinning or indeed not spinning because the one on the other side is then it is still 4WD.
..is 4WD only true if all 4 wheels are moving the vehicle or is it the case that because all wheels have the ability to move it then the vehicle is 4WD.
the difference being whether you could have all the wheels propelling the vehicle or you might be off the opinion that because all the wheels are part of the drive train then even if the wheels are spinning or indeed not spinning because the one on the other side is then it is still 4WD.
..is 4WD only true if all 4 wheels are moving the vehicle or is it the case that because all wheels have the ability to move it then the vehicle is 4WD.
