Fun In The Snow!

[s burrow]

been allowed to drive the mrs Rav4.1 today in the snow!

wow seriously impressed! plenty of grip and really annoying evryone who was doddering about!

for an old banger, its one of the best cars we have ever owned!

want a white xmas now, just so i'm allowed to drive it more!!

enjoy the snow everyone!

Steve

[rambler]

been allowed to drive the mrs Rav4.1 today in the snow!

wow seriously impressed! plenty of grip and really annoying evryone who was doddering about!

for an old banger, its one of the best cars we have ever owned!

want a white xmas now, just so i'm allowed to drive it more!!

enjoy the snow everyone!

Steve

hi s burrow

its even better with A/T tyres,just dont get too confident ....see a freelander stuck spinning its front wheels today ,they only have part time 4 wd,front wheel drive normally,rear wheel kick in if fronts dont grip....

rav4's are i believe permanent 4x4 ,none of this part time business

[chatman]

Had to go and feed and muck out daughters horse today...for some reason the wifes car would not go up the hill from our cottage... :rolleyes:

Took some pictures whilst up at stables....fun drive on all the compacted ice lanes..... :unsure: :unsure:

[Sagitar]

Had to go and feed and muck out daughters horse today...for some reason the wifes car would not go up the hill from our cottage... :rolleyes:

I wish you would have a word with the 4x4 driver who dug trenches on my little lawn last night because he couldn't turn it round in the road.

[Davrav]

I wish you would have a word with the 4x4 driver who dug trenches on my little lawn last night because he couldn't turn it round in the road.

That's just plain unnecessary and ignorant. I hope it grows back OK.

[anchorman]

Had to go and feed and muck out daughters horse today...for some reason the wifes car would not go up the hill from our cottage...

I wish you would have a word with the 4x4 driver who dug trenches on my little lawn last night because he couldn't turn it round in the road.

He probably thought it was your drive but he won't if you line it with a stinger which is what I would do because

I see it as no different to halving a walk up his front garden which I'm sure he would not like.

@rse. Was it a Land Rover? - Can't see any oil drips so maybe not.

[chatman]

Evening all.... Got some cracking pictures this morning....Lovely scenery, cold crisp day, frozen ice roads......and..................

On way to see parents in Northamptonshire....traveling along lane...which happens to have a nice bend on it....and this was the scene.. :eek: :eek:

Three cars in the ditch.....I helped get the first one out...Woman had just crashed in there, while the guy who was going to get his friends Range Rover out...She just missed him and clipped the Mercedes..then a tree... :o :o

All things we say about LR...this guys was brilliant...without the winch and a few trees all the cars would still be in their now...

This one's my favorite :rolleyes:

It was not even the lady's RR... she was driving it back...... oooops....

It is a very sharp bend...and add snow + Freezing ice = a few crashes.....

And the RAV behaved it's self and did not even slip or put a foot wrong.....Drove on upto Northamptonshire and then back.....only thing was my washer jet nozzles where frozen all the way up there....but it was -4 outside for most of the journey....

[rambler]

hi chatman

superb pics.........

yep.....winches are good................attached to any big heavy 4x4,and if that dont work,lash the 4x4 to a good sized tree !

i went to bures ,on suffolk/ essex border today for a 6 mile walk through the white crisp snowy hills,rav never put a foot wrong all the way there.

But vehicles traveling behind me were,far,far,far too close to me.....i was allowing 200 ft between me and car infront,one behind me was,i guess 30 ft maybe closer,so i dabbed to brake pedal once or twice,they soon backed off :censor:

........after they had slid around for a few sec's

me and my mates were greenlaning last sunday,had to use winch attached to a '05' hilux to 'snap' some large branches on the last one of the day....great fun...had a chainsaw as well though.

hope pic appears!

[vivianM]

been allowed to drive the mrs Rav4.1 today in the snow!

wow seriously impressed! plenty of grip and really annoying evryone who was doddering about!

for an old banger, its one of the best cars we have ever owned!

want a white xmas now, just so i'm allowed to drive it more!!

enjoy the snow everyone!

Steve

Must say my T180 went very well in the local snow Sunday evening when lot's of 2 wheel drive cars had to be passed stuck on our hills but why cannot the 22/23 MPH 4 wheel drive cut off be overridden (say) even up to 30MPH ?

The front wheel drive only is still pretty good in fairly deep snow if you are rolling when you hit it.

Very best wishes to al for a Happy Christmas from the High Peak of Derbyshire

Guy

[s burrow]

after owning a 4.3 and now a 4.1 i must admit with the 4.1 being all wheel drive i feel a lot more confident in weather like this!!

trouble is a little too confident at times!!

Steve

[Norfolk n Chance]

I don't know what all the fuss is about 4x4's.... i've had no problems whatsoever even on steep hills!

[snowjoke]

I actually found an icy hill that I needed to drive up to my gliding club on Saturday... was most satisfying being able to drive straight up it, past most of the other cars that had to park at the bottom and walk up! One lady made it part of the way up, as I saw driving past her on the way down - she was sideways across the hill, front wheels spinning and back wheels in the snowdrift at the side, after clearly having made the wrong decision to try to turn around rather than roll backwards to the bottom. She was stuck like that for a several minutes until I found a spade to clear the ice from round her wheels. Didn't take any pics unfortunately!

[MarsKy]

after owning a 4.3 and now a 4.1 i must admit with the 4.1 being all wheel drive i feel a lot more confident in weather like this!!

trouble is a little too confident at times!!

Steve

Have to agree. My brother has my old 1998 RAV4 STAX. He's been driving about thinking it's part time 4WD and the diff lock makes it 4WD. So he's had the diff lock on all this time during the snow. The thing has been beeping away and he came to me to fix it.

Anyway, got a shot in my old car after giving it away 7 years ago. Loved it, and the 4WD handling is better than my T180. But T180's comforts are too good to swap with him :D

[Plutus]

Been out in mine today and it's brilliant.

No problems in 4 -5 " snow on steep hills.

Full time 4wd is great.

Hit the shops at 9.00 and they were deserted.

Only 4 x 4's allowed on M&S inclining car park.

Everyone parked up sensibly except for 2 plonkers who were both in.....................X3's.

[jedi134]

Hmmmmmm So are the new 4.3 Rav`s only part time 4X4? If so are they using a Haldex type system? Seems that a lot of new 4x4 cars nower days are using this system. My golf 4motion has one... seems to do the trick.

[anchorman]

Hmmmmmm So are the new 4.3 Rav`s only part time 4X4? If so are they using a Haldex type system? Seems that a lot of new 4x4 cars nower days are using this system. My golf 4motion has one... seems to do the trick.

Haldex was one of my customers. I used to drive from Copenhagen airport and over that flippin big suspension bridge and then about an hour up the coast of Sweden but that was for truck disc brakes! Where was I before reminising...........

Ah yes, the Honda CRV has the Haldex system. A cracking idea which has a hydraulic pump on both the front and rear drive shafts and fluid is pumped in a circuit from front to rear and back in a loop. Normally the car is a FWD but if the front shaft spins it causes back pressure on the rear pump and the excess pressure is diverted to a clutch on the rear axle. So the Haldex system only works when a front wheel spins.

The RAV system is quite different. It has a multi plate clutch in the nose of the rear axle and a servo plunger works on a helix which can clamp up the clutch, variably on demand. The RAV ALWAYS sets off in 4WD and as the speed and torque decreases so does the clutch back off until you are coasting or cruising it reduces the drive on the rear axle until it becomes FWD only. However, it is linked to throttle load and if you squeeze the throttle it will squeeze the clutch accordingly - the best way is to imagine it being linked to the accelerator. Press to go faster and you vary the drive to the rear axle. The max drive of the rear axle is 55/45% which allows a little slip and does away with the need for a 3rd diff.

The 4WD switch engages the full 55/45 drive regardless of throttle load and is especially good for decending on poor surfaces as engine braking is applied to all 4 wheels. Cross axle wheel spin is catered for with the traction control. Although there is some slip at all times the 4WD lock drops out at 25mph as a precaution.

The system is astonishingly good in the snow.

[jedi134]

Is the system similar to this one Haldex System

I can`t find and info on the Rav4 system. You say the split is 55 front/45 rear I presume this is because the front wheels are geared higher than the rears. As far as i`m aware Haldex is all controlled electronically. In the golf the max split that i can have is 50/50.

Do you have any PDF`s for the new Rav4 4x4 system Anchorman?

[Plutus]

So Anchorman, I think you also owned a 4.2 before the 4.3.

Which do you think has the "best" 4wd sytem - the 4.2 or 4.3?

The reason I ask is that I will be going off road once or twice per week in the coming year (farm tracks, across fields etc) so I'm wondering if the 4.3 auto diesel will be as good or better off-road as the 4.2.

[anchorman]

diff.pdf rav_active_4wd.pdf

Is the system similar to this one Haldex System

I can`t find and info on the Rav4 system. You say the split is 55 front/45 rear I presume this is because the front wheels are geared higher than the rears. As far as i`m aware Haldex is all controlled electronically. In the golf the max split that i can have is 50/50.

Do you have any PDF`s for the new Rav4 4x4 system Anchorman?

Yes that is a similar haldex coupling to the CR-V and although there is a multi-plate clutch, it is the actuation system that is different. In the Haldex system it requires one of the front wheels to slip to generate the pressure differential but in the RAV it is operated by a mechanical servo. This means that it can be engaged steplessly without any front wheel slip and can therefor be used as an aid to handling and economy.

Don't get confused with gear ratios as they must be the same or the car wouldn't drive - one pair of wheels would be trying to turn at a different speed to another and that would wreck the transmission in no time. You know that a drive axle must incorporate a differential (sorry if I'm teaching grandma how to suck eggs!!!) which allows one wheel to rotate at a different speed than the other. Its because the outside wheel travels further than the inside wheel - this lovely old film explains how;

The same applies to the front and rear axle on a 4WD. The axles turn at different speeds and you can get away with it in mud or snow as the tyres slip but on a hard surface the axles fight each other and bind up. However, if you have a third diff' between the front and rear axle they can turn at different speeds and still transmit drive. However, just like a drive axle, if the front or the rear wheel gets on a low friction surface all of the drive will be diverted to that axle so you have to be able to lock it up and send equal drive to front and rear axles.

On the 4.3 there is no third diff but you can allow the drive coupling to slip and thus prevent the front and rear axles binding up. So what the 55/45 ratio means is that there is always some slip in the coupling to the rear axle and on a good road surface it will prevent something breaking under the strain.

Here are some pdf's that give more detail;

rav_active_4wd.pdf

diff.pdf

There is reference to "tight corner braking" which means that if you set off from a stand with the wheels har over to one lock, the axles will turn at different speeds. In this case the coupling is allowed to slip which prevents that bind up. In all other cases the vehicle starts at the maximum drive of 55/45%

[anchorman]

So Anchorman, I think you also owned a 4.2 before the 4.3.

Which do you think has the "best" 4wd sytem - the 4.2 or 4.3?

The reason I ask is that I will be going off road once or twice per week in the coming year (farm tracks, across fields etc) so I'm wondering if the 4.3 auto diesel will be as good or better off-road as the 4.2.

I haven't had a 4.2 although I've worked on several but that is a good question!

To summarise;

4.2 - permanent 4WD. There is no third diff and transmission wind up is avoided by allowing the transfer box to pick up on the front axle diff. On early versions with square fog lights they had a limited slip rear diff to reduce the risk of one wheel slipping on a low friction surface. On the later versions with round fog lights they use the traction control system to limit cross axle slip on both front and rear axles and there is no limited slip diff.

4.3 - 4WD on demand via a multi plate clutch on the input of the rear axle. This can distribute the drive anywhere from zero RWD to a ration of 55/45% front to rear distribution.

The 4.2 is beautifully simple and reliable means of sharing the drive between axles and of course the benefit of having both axles driven is an aid to traction and stability. The disadvantage is that it causes a certain amount of drag and can affect economy.

The 4.3 has the benefit of being able to disengage the rear axle at will and not only that but bring it in at a variable rate. This allows the full benefit of being a simple FWD for maximum economy and to turn on the rear axle by an amount to best deal with traction or stability. Remember the vehicle sets off in 4WD but as the speed increases and the demand for torque reduces the drive to the rear axle deminishes. Now if you are cruising at 50mph it will almost certainly be in FWD but now the way the coupling behaves is different. If accelerate to say, pass another vehicle, the rear axle will be engaged by a similar amount to how hard you are pressing. Think of the 4WD coupling being attached to your accelerator foot - press hard and you will bring in the rear axle fully. Feather the accelerator and the rear axle may just be applied slightly.

Which is best crossing a field? There probably isn't much to choose but the downhill assist control on the auto may be a great help. Just keep in mind that any RAV is a compromise and you can't really expect a vehicle that will return 40mpg ish at 70mph to cross a field like an old nail of an LR with all lockable diffs, a low box and knobbley tyres.

OK - we have established that the system can assist traction and now most of us have had a play in the snow you can see that it is very good compared to all those front or rear wheel drives slipping about and getting under the feet. However, if you want to consider where the real benefits are you have to think about how it can be integrated into the VSC (vehicle stability control) and it can be taken a step further by integrating the steering, traction control, brake assist and ABS. This is what Toyota refer to as "Integrated Active Control".

So. The RAV has electric power steering. It does away with the pumps and belts and hydraulics and is only used when needed so aids fuel efficiency. A strain gauge in the column measures the amount of effort being applied and can give more assistance when parking and less when on the road - this improves feel. But it also means that it easy to measure steering angle and it also means that if you do get into a skid it will determin which way you need to turn to correct the skid and either assist you to turn it the correct way or resist (but not prevent) you to turn it the wrong way. Under the passenger seat there is an acceleration and yaw rate sensor which is attached to the main ECU. Imagine you are on a road travelling at 50mph and the road bends to the right. It knows how fast you are going and it knows how tight the bend is by the steering angle sensor in the column so the sensors under the seat check to see that they are experiencing the correctly mapped amounts of acceleration and yaw. If it does then the system sleeps with one eye on the weak link (err - thats you). Imagine the road is slippy and when you enter the curve the vehicle begins to drift out to the left. The ECU cannot reconcile the lack of inertia from the under seat sensors with the speed and the steering angle - it knows you are in trouble and now the sleeping giant is awakened. Like it or not, the ECU can think quicker than you can and will take the vehicle virtually out of your hands; It may in any amount:-

-take the power off the engine

-resist you turning the steering the wrong way but assist you to turn it the right way

-apply any one or up to all four of the brakes without you touching the pedal depending on what kind of skid you are in order that re-align the vehicle on the intended course (for instance applying one inner rear brake may assist in pulling the car back into line in the case of a rear wheel skid - and yes the computer mapping tells it whether you are in a front or rear wheel skid). Not only can it do this but it can apply different brakes by different amounts

-if you are braking because you need to reduce the speed at the same time as turning the bend it will look at how you pressed the brake pedal. If you stamped on it then it will consider that an emergency and will generate brake pressure by up to double on your behalf. However, if you pressing on the pedal too hard is having an adverse effect on regaining control it will completely over-ride that and may release the brake

-use the ABS system to modulate (apply and release) any brake that is on the limit of adhesion

-either bring in or take off the drive to the rear axle to assist the situation - in some cases a little and in some cases fully

-in the case of an impact, deploy one or more airbags, take the slack out of the seat belts and on the latest RAVs allow the back of the seat to follow you forward thus reducing whiplash

It can do any one or any combination of these things while you are deciding what day it is and why that orange light is flashing. Only when it establishes that all the parameters suggest the vehicle is under control will it hand it back to you. As Chris said recently, it cannot defy the laws of physics and as long as things didn't go badly wrong then you hopefully won't end up down at A&E getting the Hawthorns out of your gums and the dry stone wall out of your rib cage.

The later 4.2s have VSC but only the 4.3s have active control. To my eyes the 4.2 looks nicer - especially the 3 doors but in my humble opinion, if you are able to choose between a 4.2 and a 4.3 you can expect the latter to go some way further in reducing the risk or effect of an accident. It is reasonable to expect that handling and performance have been improved. Off road? I don't know but probably similar and maybe that downhill or hill start assist may just swing it???

Sorry for rambling.

[Ravke]

Take a look here

Comment is in German,sorry

conclusion they made the rav4.2 is the best one for this test

His system respond's faster then the 4.3

1 ) Rav 4.2

2 ) Rav 4.3

3 ) Rav 4.1

[three5]

So Anchorman, I think you also owned a 4.2 before the 4.3.

Which do you think has the "best" 4wd sytem - the 4.2 or 4.3?

The reason I ask is that I will be going off road once or twice per week in the coming year (farm tracks, across fields etc) so I'm wondering if the 4.3 auto diesel will be as good or better off-road as the 4.2.

I haven't had a 4.2 although I've worked on several but that is a good question!

To summarise;

4.2 - permanent 4WD. There is no third diff and transmission wind up is avoided by allowing the transfer box to pick up on the front axle diff. On early versions with square fog lights they had a limited slip rear diff to reduce the risk of one wheel slipping on a low friction surface. On the later versions with round fog lights they use the traction control system to limit cross axle slip on both front and rear axles and there is no limited slip diff.

4.3 - 4WD on demand via a multi plate clutch on the input of the rear axle. This can distribute the drive anywhere from zero RWD to a ration of 55/45% front to rear distribution.

The 4.2 is beautifully simple and reliable means of sharing the drive between axles and of course the benefit of having both axles driven is an aid to traction and stability. The disadvantage is that it causes a certain amount of drag and can affect economy.

The 4.3 has the benefit of being able to disengage the rear axle at will and not only that but bring it in at a variable rate. This allows the full benefit of being a simple FWD for maximum economy and to turn on the rear axle by an amount to best deal with traction or stability. Remember the vehicle sets off in 4WD but as the speed increases and the demand for torque reduces the drive to the rear axle deminishes. Now if you are cruising at 50mph it will almost certainly be in FWD but now the way the coupling behaves is different. If accelerate to say, pass another vehicle, the rear axle will be engaged by a similar amount to how hard you are pressing. Think of the 4WD coupling being attached to your accelerator foot - press hard and you will bring in the rear axle fully. Feather the accelerator and the rear axle may just be applied slightly.

Which is best crossing a field? There probably isn't much to choose but the downhill assist control on the auto may be a great help. Just keep in mind that any RAV is a compromise and you can't really expect a vehicle that will return 40mpg ish at 70mph to cross a field like an old nail of an LR with all lockable diffs, a low box and knobbley tyres.

OK - we have established that the system can assist traction and now most of us have had a play in the snow you can see that it is very good compared to all those front or rear wheel drives slipping about and getting under the feet. However, if you want to consider where the real benefits are you have to think about how it can be integrated into the VSC (vehicle stability control) and it can be taken a step further by integrating the steering, traction control, brake assist and ABS. This is what Toyota refer to as "Integrated Active Control".

So. The RAV has electric power steering. It does away with the pumps and belts and hydraulics and is only used when needed so aids fuel efficiency. A strain gauge in the column measures the amount of effort being applied and can give more assistance when parking and less when on the road - this improves feel. But it also means that it easy to measure steering angle and it also means that if you do get into a skid it will determin which way you need to turn to correct the skid and either assist you to turn it the correct way or resist (but not prevent) you to turn it the wrong way. Under the passenger seat there is an acceleration and yaw rate sensor which is attached to the main ECU. Imagine you are on a road travelling at 50mph and the road bends to the right. It knows how fast you are going and it knows how tight the bend is by the steering angle sensor in the column so the sensors under the seat check to see that they are experiencing the correctly mapped amounts of acceleration and yaw. If it does then the system sleeps with one eye on the weak link (err - thats you). Imagine the road is slippy and when you enter the curve the vehicle begins to drift out to the left. The ECU cannot reconcile the lack of inertia from the under seat sensors with the speed and the steering angle - it knows you are in trouble and now the sleeping giant is awakened. Like it or not, the ECU can think quicker than you can and will take the vehicle virtually out of your hands; It may in any amount:-

-take the power off the engine

-resist you turning the steering the wrong way but assist you to turn it the right way

-apply any one or up to all four of the brakes without you touching the pedal depending on what kind of skid you are in order that re-align the vehicle on the intended course (for instance applying one inner rear brake may assist in pulling the car back into line in the case of a rear wheel skid - and yes the computer mapping tells it whether you are in a front or rear wheel skid). Not only can it do this but it can apply different brakes by different amounts

-if you are braking because you need to reduce the speed at the same time as turning the bend it will look at how you pressed the brake pedal. If you stamped on it then it will consider that an emergency and will generate brake pressure by up to double on your behalf. However, if you pressing on the pedal too hard is having an adverse effect on regaining control it will completely over-ride that and may release the brake

-use the ABS system to modulate (apply and release) any brake that is on the limit of adhesion

-either bring in or take off the drive to the rear axle to assist the situation - in some cases a little and in some cases fully

-in the case of an impact, deploy one or more airbags, take the slack out of the seat belts and on the latest RAVs allow the back of the seat to follow you forward thus reducing whiplash

It can do any one or any combination of these things while you are deciding what day it is and why that orange light is flashing. Only when it establishes that all the parameters suggest the vehicle is under control will it hand it back to you. As Chris said recently, it cannot defy the laws of physics and as long as things didn't go badly wrong then you hopefully won't end up down at A&E getting the Hawthorns out of your gums and the dry stone wall out of your rib cage.

The later 4.2s have VSC but only the 4.3s have active control. To my eyes the 4.2 looks nicer - especially the 3 doors but in my humble opinion, if you are able to choose between a 4.2 and a 4.3 you can expect the latter to go some way further in reducing the risk or effect of an accident. It is reasonable to expect that handling and performance have been improved. Off road? I don't know but probably similar and maybe that downhill or hill start assist may just swing it???

Sorry for rambling.

Anchorman,

think that you should pin this posting in the technical section at the top of the forum. I now UNDERSTAND far more about how the motor that I have been driving for 21 months actually works. Another masterpiece!

[Plutus]

Thank you both for the replies.

The 4.2 performed flawlessly on Christmas Day in the snow.

Collected 17 elderly folks (6 runs) and took them to lunch and then returned them afterwards.

Up and down snowy hills no problem.

Been superb.

Thanks again Anchorman.

[jedi134]

Anchorman, do you know what make the rear diff/coupling is? is it a Haldex system? or another manufacturer, Also are there any oils to change with the rear wheel drive system. On the golfs haldex there is the normal diff oil to change (75w/90 etc), but there is also the Haldex multi clutch oil and filter to change. Would be interested if Toyota actually do this service if necessary.

The reason i ask is, when I bought the Golf, it was around 2 years old at the time the VW dealership did not know that there was a 4x4 version golf, had never heard of a Haldex system????? and never stocked the oils or filters for it. Shocking!!!!!!!!!!!!!!! This is another reason I steer well clear of main dealers, they don`t know their own products, well VW don`t anyway. And of course if anything should go wrong with it who is to blame.

[anchorman]

The coupling for the 4.3 is designed in house at Toyota (although I wouldn't like to say who makes it as that could well be a third party). It is completely self contained including the lubricant and nowhere near as complex as the Haldex unit which has pumps and filters etc. Presumably at some stage it will wear out and is intended to be a throw away unit bolted to the nose of the rear diff. I have serviced similar things in the past but it depends on the availability of the discs and in any case they tend to have a very long life - 100s of k miles.

It is shown on this diagram as the "Electromagnetic Coupling";

rear_diff_unit.pdf

The oil for the rear diff is regular EP90 which is available anywhere and dead easy to change at the 2 year service interval;

rav_service.pdf

Having said all this your 4.2 doesn't have this system or is it another one you are concerned about?