theoretically speaking

[blackpoolsparks]

Q- Why can't I use 4x4 mode all the time or on the roads?

A- There's drive to both axles and the front and rear axles have different turning circles. On hard/dry surfaces like tarmac there's no give on the road surface so you'll end up with windup on the transmission which can destroy it.
Permanent 4WD vehicles like Range Rovers have a differential in the transfer case to allow it to slip as you turn in circles. The Surf is not intended as a permanent 4WD vehicle

So theoretically you could drive in 4wheel drive on a hard road, as long you dont turn sharply, like on the motorway????

what do you think???

[Predictable Bob]

I think that anybody that tries it will end up well wound up with the distinct possibility of a large bill if they aren't very lucky !

[Sancho]

Theoretically, yes, if you stayed perfectly straight. But it won't be happy changing back to 2wd at high speed, so you'd never be able turn.

[BioHazard]

And the long term stress on the front drive shafts

[Apache]

If there's ANY difference in the rolling circumference front to back, then you'll break something.

Cant for the life of me think why it would be hard to turn with 4wd on. That would only be an issue if you had locked diffs of a non-slippy surface because of the different lateral wheel speed when you turn. Shouldn't make any difference front to back as that relationship remains the same.

An old mates rally car had LSD axles for loose / gravel stages. That was a bugger to turn on tarmac, and would never track straight on tarmac either.

[Smego2]

I leave mine in 4WD most of the time, no issues at all.

[Ava_Banana]

I leave mine in 4WD most of the time, no issues at all.

..the benefits of a 3rd gen.

...although doesn't it adversely affect the fuel consumption?

[Apache]

It *MUST* affect fuel consumption as there is more drivetrain to drive, so more frictional losses.

How much, I dont know, but it seems a bit pointless to do it unless it's necessary (loose / slippery), and in that situation, you could do it with a 2nd gen too!

[Predictable Bob]

But isn't there a situation where it isn't slippery enough to use a 2nd gen in 4wd but roadholding would be improved by using 4wd in a 3rd gen ?

[Sancho]

But isn't there a situation where it isn't slippery enough to use a 2nd gen in 4wd but roadholding would be improved by using 4wd in a 3rd gen ?

Probably. Driving through snow or when black ice is a risk - I can't think of much else though. It's not like it's possible to drive a surf fast enough to need the extra traction.

[Apache]

Ah, but having 4 wheel drive on the road means you can ignore the road conditions and drive like a tw*t doesn't it?

<remembers a brand spankin Rangey going straight into the back of a parked Dray outside a malvern pub in the snow in early last year...>

There is a difference between 'traction' and 'grip'. Grip is the same whether in 4WD or not and is largey dependent on the suitability of tyres to conditions. I cant imagine a situation ON THE ROAD when you'd definitely NEED 4WD, but the road grip is too high to use it!

[Sancho]

There is a difference between 'traction' and 'grip'.

Thats' what I mean, you're going to run out of grip in a surf (especially if you've no ARBs ) long before you're going to need the traction to get back out of the corner.

[Apache]

I know its a troll, but grip wont be affected by ARBs. Perversely, you're more likely to lift a wheel in hard cornering with ARBs fitted.

I have my front one fitted on the road these days because I got fed up having to hang on to the seat on roundabouts. Only takes five minutes to remove if necessary.

[BUSHWHACKER]

Q- Why can't I use 4x4 mode all the time or on the roads?

A- There's drive to both axles and the front and rear axles have different turning circles. On hard/dry surfaces like tarmac there's no give on the road surface so you'll end up with windup on the transmission which can destroy it.
Permanent 4WD vehicles like Range Rovers have a differential in the transfer case to allow it to slip as you turn in circles. The Surf is not intended as a permanent 4WD vehicle

So theoretically you could drive in 4wheel drive on a hard road, as long you dont turn sharply, like on the motorway????

what do you think???

It's the transfer case that breaks not the transmission/gearbox, because it is chain driven and both front and rear driveshafts are constantly turning.

[blackpoolsparks]

Heres why i asked.
Last year I drove up to Drumclog in a pretty bad snow storm. Only one of the lanes on the motorway way driveable as the other two were snow bound. I used the middle lane to pass, but no way was anyone using the outside lane.

That was in a standard Surf with street tyres and I did NOT use my 4 wheel drive as I wasnt sure.

I am going back to Drumclog in the next few weeks and may encounter similar conditions. My truck is now lifted way high and I run on MTs, so loads less traction.

So would you consider drifting snow loose enough to allow for slippage when in 4 W.D.
Mind Im only talking 30 - 40 mph