Driving across farmland, went downhill on hill control and on to a plank "bridge" over a boggy bit. Put a front wheel wrong and dropped off the planks. One front wheel spinning in the muck and one back one spinning in the air! Towed out by a Range Rover (the shame of it ). One interesting point if you are ever as daft as me - the tow eye screws in anti-clockwise!

Now I have to clean her up.

Oops!!

Ooopsy!

If it's any consolation it could have happened in any 4x4 by the sounds of it and any 4x4 in that situation wouldn't get moving on it's own.

Phil

I thought it would hsve used the brakes to slow the spinning wheels and transfer some drive to the other side of the axle, unless there was not enough grip there to move the vehicle either.

Thanks for the oops Bossfox - I confess I thought the way the system works it might do something like that. On the other hand, it was not the sort of situation you would ever try to get into and it maybe that your thoughts on grip are right. Might have done better if I had proper off road tyres but, like most of us, I use it on the road 99% of the time.

Driving across farmland, went downhill on hill control and on to a plank "bridge" over a boggy bit. Put a front wheel wrong and dropped off the planks. One front wheel spinning in the muck and one back one spinning in the air! Towed out by a Range Rover (the shame of it ). One interesting point if you are ever as daft as me - the tow eye screws in anti-clockwise!

Now I have to clean her up.

Hope you told the Range Rover owner that your name was 'John Smith, and that you live in London.

I thought it would hsve used the brakes to slow the spinning wheels and transfer some drive to the other side of the axle, unless there was not enough grip there to move the vehicle either.

I guess this is where "real" left-right diff locks would become useful! I've always wondered if 4x4 is worse than 4x2 without diff locks ( ie any 1 of 4 wheels spinning means no traction, vs 1 of 2...).

I'm pretty sure it tried to use the brakes as when I reversed there was a series of jerks. I think it was braking the spinning wheel but then finding the other one spinning instead. I don't know enough about the technicalities to comment on diff locks. For me it's just reinforced what i already knew (but briefly forgot) that 4wd is not a magic carpet and that it's the nut behind the wheel that causes most of the problems.

I once heard an american comedian say that before 4wds people went out into the woods at weekends and got 2 wheels stuck in hub deep mud. Now they get all 4 stuck

I guess this is where "real" left-right diff locks would become useful! I've always wondered if 4x4 is worse than 4x2 without diff locks ( ie any 1 of 4 wheels spinning means no traction, vs 1 of 2...).

I don't know your understanding of 4 wheel drive systems, but the only 4x4s that get stuck if one wheel spins are the very old ones. Or a Defender with no traction control if you forget to put it in difflock. All modern systems account for this and even with two wheels spinning (one on each axle) they will get you moving IF there is enough traction on the other side. But if there is not enough traction it'll just sit there spinning.

In this case I very much doubt there was enough traction.

Particularly as it's on road tyres.

I have personally tested my Yeti by parking with the two passenger side wheels in slippery mud and the driver side wheels on the road.

Hit the accelerator and it pulls away very well because the traction control and 4x4 system does what it's supposed to, ie, it brakes the spinning wheels when you apply power to generate more spin so the car knows there is a problem.

Worth knowing that if you run it at tickover rpm or not much higher the system does not work as well.

You have to use the throttle a bit so it's easy for it to see there is a lack of traction.

You could have at least got pictures

You could have at least got pictures

OK - I'll go back and do it again :sun:

OK - I'll go back and do it again :sun:

Result

All modern systems account for this and even with two wheels spinning (one on each axle) they will get you moving IF there is enough traction on the other side.

I wonder about this. See the very final seconds of this video

(1 minute 11 sec onwards), showing a Freelander having trouble moving when two diagonally-opposite wheels are spinning but the other two have plenty of grip. (Just to be clear, I'm not referring to the start of the video.)

I don't know much about 4WD systems in practice, so any explanations will be welcome.

Can't see the video, as I'm at work, but the one problem when teaching Freelander owners about off-road driving was to teach them that when they started to feel the wheels spinning to keep the power ON, which completely goes against what you feel you should do. As soon as any power is taken off the system it reverts to it's normal FWD mode. From experience the Yeti is exactly the same; you have to keep the power ON to get the Haldex, etc to work.

As an aside, whilst looking on here at silly o'clock this morning I saw the header for "mytyres" and had a look at why they had to offer in 17" size, and in their "all seasons" section they now list the General Grabber UHP (http://www.mytyres.co.uk/cgi-bin/rshop.pl?details=Ordern&cart_id=23624000.110.22866&typ=R-170512&ranzahl=4&Breite=225&Quer=55&Felge=17&weiter=0&kategorie=6&Ang_pro_Seite=15&Transport=P&dsco=110&sowigan=GAN) that have a reputation as an excellent mostly tarmac All Terrain, all temperature tyre. Price wasn't bad either, and they get a good review.

I wonder about this. See the very final seconds of this video

(1 minute 11 sec onwards), showing a Freelander having trouble moving when two diagonally-opposite wheels are spinning but the other two have plenty of grip. (Just to be clear, I'm not referring to the start of the video.)

You can't see enough of what is going on.

You can't see enough of what is going on.

Offside rear is in the air, nearside front is spinning noisily, other two wheels are taking all the weight, and the car is going nowhere.

My car didn't do too bad with wheels off the floor on the meet in the Elan valley, I have also had it on wet squidgy grass and noticed that if you keep your foot down a bit the electronics do their thing and somehow keep you moving, I am sure there is a limit though.

How about this, then?

Comments, anyone? Is the car having more trouble finding traction than you would expect?

Nothing wrong with the car on that video , just the driver, he should have taken a wider angle instead of turning too early

Looks like Gary Glitter driving it too!!

Tyres are everything...So many people think that 4 wheel drive will give them traction in all conditions and surfaces!!

If anyone went to the British F1 GP this year you will have seen that getting stuck is pretty much all down to the driver :-) I lost count of the amount of Range Rovers and Discoverys stuck. I drove round one in my Seat Leon !!!

If anyone went to the British F1 GP this year you will have seen that getting stuck is pretty much all down to the driver :-) I lost count of the amount of Range Rovers and Discoverys stuck. I drove round one in my Seat Leon !!!

LOL! I've certainly had traction problems in a Discovery (diff locks don't defeat the laws of physics!) once or twice, driving where in retrospect a tracked vehicle (or M&S tyres at least) would have been more appropriate. I'm sure 4x4 gives many LR / RR owners a sense of overconfidence in a muddy car park (social comment: owners of such vehicles are not usually going to be under-confident folks, and some likely won't have RTFM re 4x4 operation )

Edited 14 October, 201213 yr by Totally Square

Yes, better driving or better tyres might have avoided this, but those are truisms (always the case) and have nothing to do with the particular point I'm making. The point is that there is no loss of grip on two wheels, yet the car can hardly progress. Those two wheels are diagonally opposite each other, and not enough power is being diverted to them from the wheels that have no grip.

This situation - a weakness when diagonally-opposite wheels lose grip - would appear to be the case in both the videos I have posted and also what happened to the OP in this thread.

So I'm asking those who have extensive experience of 4WD in demanding situations: it is true that either Haldex systems, or indeed 4WD systems in general (since one case is a Freelander) have trouble when diagonally-opposite wheels lose grip?

Did you have "Off Road Tech"? The Australian Brochure shows EDS (electronic diff lock) as part of the "Off Road Tech" and not part of the usual ESP (Electronic Stability Program)

http://www.skoda.com.au/yeti/safety.aspx

In both videos it is noticeable that as soon as the wheels start spinning the driver eases off on the throttle, so I go back to my comment at #14; keep the power on!!

Interestingly in the initial Freelander one, at the very beginning where the noise is commented upon, the driver does exactly that. I think the noise was the braking module shifting valves, as from 7 years experience of Freelanders the initial noise that made was alarming, especially as there was no warning about it.

Joel, not all 4x4 Yetis have the Off-road button.