Hi, does anyone have a definitive answer on what system Fiat now uses on the Panda 4X4?
I've read on this forum the many issues people have had with the solenoid actuation of the rear wheel drive but have a couple of other concerns.
Does the 'new' system now effectively lock the front/rear diff? If so. is there any chance of transmission wind up like the Panda Classic 4X4 use to suffer from?
What was wrong with the Viscous Coupling system that every road test raved about?
I've not read any complaints, anywhere, about the, supposed, delay in rear drive kicking in when the fronts slipped. I know that the viscous fluid used in these coupling achieves it's maximum viscosity unbelievably quickly so why change what many other manufacturers have remarkable success with. Most notably, Volkswagen.
Why does the Multijet Cross only get drum brakes at the rear?
What is the point in that?
And, Finally, just like many, many other members, I would love top know when Fiat are going to stop rehashing the current models with tart ups and get down to some proper development work and bring out a 1.6 vewrsion of this fantastic diesel engine.
Sorry to go on but, Come on Fiat. Get your fingers out.

Which 4x4?

There are 2 types available

Multijet.
Cross? No, Livid! lol.
Sorry about that.

All Panda Crosses sold in the UK use a solenoid to connect the drive from the prop shaft to the rear diff (note this engages 4x4 but does not lock the diff. However, the rear diff can be locked too, via a switch on the dashboard, and pressing this will force it into 4x4 mode. The diff lock is automatically turned off if speed rises over 30km/h [18mph] specially to prevent transmission wind-up)

Panda 4x4 Climbing (ie the petrol car without the extra bodywork bits and with rectangular headlamps) up until the 2009 model year used the viscous coupling. I believe any bought from 2009 onwards now use the same electrically-engaged 4x4 system as the Cross.

Why the change: most likely because it allows the effective use of ESP (this would not have worked with a viscous coupling, as that needs the front wheels to spin to engage: ESP would prevent front wheel spin. With a fully electonically controlled system it can detect the difference between spinning due to over-powering, and slipping due to loss of traction), and also probably more economical driving (with viscous coupling there is always some drag)

Does the Cross have rear drums? I thought it had the same rear discs as the 4x4 Climbing, and at the front uses larger 257mm discs. However, for a time the Multipla was fitted with rear discs and then reverted to the drums used on earlier models (like mine), which I believe was owing to not being able to get the brake balance right with discs all round.

(As an aside, did you know that in Italy you can by a 2WD Panda Cross with methane gas power...? )

Most Easterly Pandas said:

Which 4x4?

There are 2 types available

Click to expand...

and both (if bought new now) use the electronic system

Not much help here, but the Cross i drove back in August 2008 had rear Discs (and the famous 4x4 not available message too!)

Fiat's website says the Cross has drums... but then it also says (of the diesel-engined Cross) "But don't think that it drinks petrol though - the Panda Cross is a frugal off roader..."

I suspect the site is full of silly errors like this. The 2009 printed brochure says it has 240mm rear discs.

Pete

Well thanks for all the input guys. I still can't help but think that it's a retrogressive step though.
Whilst I accept Hillhopper's comments regarding the ESP several other car manufacturers manage to get this right whilst still retaining the benefits of the viscous coupling and lack of 4X4 not available messages!
On another note; The rear diff doesn't actually lock. The system uses the ABS to brake the wheel that is slipping. No matter how flexible a manufacturer's explanations appear they still can't get away from the fact that there is a substantial difference between locking a differential and braking wheels individually as they do in the classic hillclimb cars. I believe that was called using fiddle brakes. Been around donkey's years that one. Not exactly cutting edge is it?
The reason the "Diff lock" cuts out at 30KPH is so you don't burn out the brakes.

huskysled said:

On another note; The rear diff doesn't actually lock. The system uses the ABS to brake the wheel that is slipping.

Click to expand...

Correct: I explained this in another post somewhere but simplified the answer here

huskysled said:

The reason the "Diff lock" cuts out at 30KPH is so you don't burn out the brakes.

Click to expand...

Good point - hadn't thought of that.

Huskysled you are wrong instating that Volkswagen use a viscous coupling for their 4x4 systems. All the transverse engine cars in the Volkswagen group use Haldex 4x4 systems. These have a hydraulic clutch between the prop shaft and the rear differential.

The other vehicles of the Volkswagen group (mostly those with longitudinal engines) use a variant of the torsen differential. This is a mechanical limited slip differential.

I believe that volkswagen /audi may have used viscous couplings at one time in the original quattro, but no longer.

The exact mode of operation of the Panda 4x4 system remains something of an enigma. It is not supplied by Haldex but putting the bits and pieces of evidence together it seems to be similar to the Haldex concept. i.e. the 4x4's are not permanent but switched in by a control unit that monitors the difference in wheel spin between front and rear. How much control of the torque transfer there is between front and rear I don't know. By using the ELD mode the front/rear coupling is locked and the ABS system used to brake individual slipping wheels so torque is transferred to those with grip.

The Cross has disc brakes all round.

Aha! Thanks very much for that.
It does seem strange that Fiat seem to be a tad secretive about their 4WD system. Most other manufacturers are generally proud to advertise their chosen method.
I wonder if we'll get a little more info if, and when, Jeep take the Cross on board as mini Jeep?
I know the US market demand info so we may get the truth that way.
Let's hope so anyway.
I also look forward to loads of new accessories if Jeep take it on. Most of the profit in US car sales is taken from extras so hopefully there will be a huge choice.

Think that 'Jeep/Panda' was a joke/hoax that has now done the rounds. (Bit of clever photoshop work from a speculator) But may be wrong on this...

[deleted and replaced by next entry...]

For more detail on the Fiat/Jeep line up in years to come, see here:
http://www.autocar.co.uk/News/NewsArticle/AllCars/244658/

No talk of Panda, only of larger vehicles and of Chrysler (Jeep's parents) using Fiat Technology in their own engine designs

Pete

The viscous may have got the chop due to cost and maybe complaints that it is not a fixed 4wd system. Maybe the slip allowed between the front and rear allowed too much loss of control when manovureing (sp) on hillsides?

Also does the new 1.2 climbing get the new 69bhp engine?

I dont think Fiat have been particularly secretive about the 4wd system, it works for thousands of people who depend on it every day and that is enough. The ELD has always been an option in Europe even on the earlier viscous equipped cars it is just Fiat UK that have knocked it off the options list. Maybe they are to blame for the lack of technical data.

Alot of other manufacturers use the brakes as a difflock, nearly all I imagine now as the hardware is fitted as standard due to the ABS, EBD and ESP.
LandRover introduced it on the Range Rover in 1992. It is a poor mans difflock as can get through a set of pads in a days playing but is also better than nothing. Fortunately I have the pleasure of offroading vehicles built by Steyr Puch (who built the original Panda) which have genuine difflocks fitted front and rear so no wear on the pads but you can put full torque through 1 wheel, even a front one at full steering lock which might not be too clever.

The ELD will not be active over 30mph as a safety interlock, having the rear wheels braking independently during a high speed corner wouldnt be good. Is there are speed kickout on the 4wd too?

Also, the OP makes reference to a 1.6 diesel. Fiat already make one. It wont be seen in the Panda but the Multijet2 will eventually be used.

Very interesting thread. Having had a history of Land Rover products in the past, I too have taken a very keen interest in the detail of the hardware used in my cars.

And I have to say that the Panda 4x4 (mine's an 06 model with 15,000 miles thus far) is truely amazing in snow and offroad as it stands, which I put entirely down to its low weight and grip:weight ratio.

Viscous couplings, as was said earlier, are now very effective devices and for applications where simplicity is paramount, coupled (sorry!) with not requiring input from the driver, they are really most excellent. I suspect they are relatively expensive and with the ever marching progress with onboard electronics, it was only a matter of time before quick acting, cheap, switchable systems came to the fore. But with them comes unreliability, as we have seen.

Having installed true difflocks in my last Discovery (a pneumatically driven device called an ARB Locker), there really is no alternative when it comes to full lock with full control and if they made one for the Panda read diff, I'd get one tomorrow. Still on the lookout for something similar, so if anyone knows of such a thing.......!

But, having said all that, with simply the viscous coupling on the nose of the prop and open diffs front and back, these little scams find grip that has amazed everyone without exception, that I've driven around recently in the snow. I've towed cars up hills, out of drifts and gone places I would have feared to tread in my snorkel and ARB equiped Discovery (proper 1993 mechanical job, not a modern electronically managed version). and all that on the original Bridgstone Duelers too. Land Rover products have grip (assuming that the owner has NBOT elected to go for 22" Kings Road tyres of course!), but too much weight and this makes them a liability going down slippery decents. I followed a fully ABS'd-and-not-slowing-one-bit Volvo XC90 down a steep hill last week, yet I could have stopped when I wanted. She slid into a mud bank and made a mess of the front of the car. I stopped and then even reversed back up the slope to warn others.

XC90 driver could not understand how the Panda did it!

Sorry for the ramble, but I had to get it out of my system - bloody love these cars!

Now, where can I get that rear diff locker......?!

Regards,

Phil G

I joined the forum not long ago and just came across this old thread from 2010. Still very interesting to read nevertheless.

The viscous coupling unit on Panda 4x4 was from GKN Driveline. Actually, I had some email exchanges with their technical department about the VC on Panda 4x4. I asked them which solution is better: VC or Solenoid.

I don't have the emails anymore but I remember the tech guy from GKN Driveline never answered my question directly, but replied that VC is a "robust" system and it has a long lifespan under normal use. They also told me Fiat went for the solenoid solution mainly because it's more compatible with ESP.

This year, finally, I bought a Panda 4x4 Climbing registered in 2005. I emailed GKN again to ask them what is the best way to test the VC, but they never replied this time.

Can anyone advise the best way to test the VC without destroy it in the process?

What do you mean test it

Most Easterly Pandas said:

What do you mean test it

Click to expand...

To test if the VC is still able to transmit enough power into the rear wheels to push the car foward in the event of the front wheels slipping. My panda is 5 years old already...

Ironwhip said:

Can anyone advise the best way to test the VC without destroy it in the process?

Click to expand...

Wait until freezing weather. pour some water on the floor to make puddles. Wait till freezes, drive front wheels onto ice, then wheelspin off

I'm sure that would be most satisfactory