Electric Differential Lock

[pjondeck]

I have paid $1690 for the EDL on my new 132DSG T5. The handbook tells me nothing about it. I understood that when I operated the button on the dash the diffs would lock and I would have dedicated 4WD. From what I have been able to find on the web I'm now not sure that this is the case. What does it give me beyond 4MOTION? Can anyone out there please educate me? I'm about to drive in the snow and don't plan to take chains.
thanks
PD

[IN2VWS]

"EDL
The Electronic Differential Lock (EDS) is a Volkswagen technology which was developed to substitute most of the attributes of a conventional differential. Instead of being a mechanical device which regulates the torque distribution between two or more drive wheels, EDS uses the ABS sensors to detect wheelspin and brake each wheel individually , thus creating the illusion of torque distribution. Due to the stress it can create on the brakes by hard use, the system only works up to speeds of approximately 25 mph."

[4wheels]

Hi PD,
The following relates to my 2007 128 4Motion Trakkadu, but I haven't heard that there is any difference with the diff-locking features on a T5GP. My understanding is that the front diff-lock is standard issue on all T5's (at least the high powered ones, and including 2wd), and it works as IN2VWS described, and is there all the time (ie. no switching on/off required). The rear diff-lock is the optional one (in my day it cost about $1300). The rear diff-lock is a full 100% mechanical lock-up, electrically activated by the dash button. It operates up to 40Kmh, if I remember, and, of course, can only be used on loose surfaces. It is very useful on twisty off-road sections where you are likely to have a wheel in the air, but I'm not sure how much it adds on flat but slippery surfaces like snow roads. Traction in a 4Motion is very good anyway. Traditional mechanical front diff-locks (as were available on the T3 Syncro) would just about be a disadvantage in those conditions, as they seriously compromise steering abilities. That is, if you have a front (mechanical) diff-lock on, you're pretty much only going straight.

Good luck in the snow, and I'll be interested to hear how you go. I'm sure you'll surprise many regular 4wd's.

Brian R.

PS. I haven't been to the alpine regions much, but my understanding was that you had to carry chains anyway, even if you're in a 4wd/Awd, and may not need them.

[wai]

EDL operates on the one axle only.

If the wheel speeds (left and right) differ by more than the amount when a vehicle is turning on maximum lock, then the system says that one wheel is slipping and so locks the differential so that both wheels turn at the same speed.

All wheels are driven when the system determines that all wheels need to be driven. It is not necessarily constant 4WD.

On chains and snow, you might still find it a requirement that you fit chains beyond a certain point. 4WD does not necessarily negate the need for chains.

[Sunny43.5]

Hi guys I wonder how much more benefit a 4 wd system would add to a T5 van , I found out just after we bought ours in 2005 how the ASR worked . We were Moto Cross riding at a place called Black Duck Valley here in SE Qld after a night of heavy rain we decided to leave early , after packing up all our camping gear 3 MX bikes on the trailer and 5 passengers we were concerned about getting out of the park . You see the location is black soil country this stuff is like glue if you walk on it after rain your boots grow inches with each step . We saw many conventional cars being towed out by a tractor as there are some gullies that cross the road out of the park and being just front wheel drive I was concerned , we took off and approached the first gully the mud was very evident from the other cars that had gone before us , I warned my passengers it could be trouble as we got to the bottom of the gully I put my foot down the van surged forward and suddenly I felt the front go sideways . Then to my amazement the ASR took over I had my foot still down on the accelerator but the van just crept forward by itself slowly .We had to go about 30 metres uphill in this mud and we got to the top , the park manager was watching us and asked what I had done to the van as he said the front wheels were behaving strange , I said I didn,t care as it had got us up a hill that all others had failed and had to be towed up and remember this was with a trailer and front drive only . A second hill a little further along the track was also completed the same way , 4wds eat your heart out !!!

[Cousin]

pjondeck, check where you're going before you head out without chains
Police patrol looking for chains either carried or fitted in parks that mandate them
Not sure the exact fine, but it's around a couple of hundred dollars
I was up at Mt Hotham last Thursday, very little cover about after the warm weather, but still had to take some
Begs the question though, do you have to fit all four wheels on a 4 Motion?
And also check the thickness of the chains you get
The last set I hired were quite thin, but I just barely got my finger between the chains and shocker
Not really enough room, can get a bit noisy banging around in there
Stock wheels, 235/55/17


M

[pjondeck]

On AWD/4WD

Hi all
Thank you for the insights on the electric diff lock.
I have printed the NSW Government Vehicle Standards Information sheet #57 "Driving in snow and ice conditions".
Clause 25 of the National Parks and Wildlife Regulation 2002 requires that persons travelling by motor vehicle, except four wheel drive vehicles, on any designated snow/ice risk road within Kosciusko National Park, at any time during the designated snow season....must carry snow chains and fit them when directed by an authorised officer.
A little later in the sheet it says "the Regulation acknowledges this by excluding persons driving 4WD vehicles from the requirements to carry and fit snow chains..
It does then say that the RTA RECOMMENDS that persons driving 4WD vehicles take measures to improve the vehicles performance capabilities by either:
Fitting winter tyres to the vehicle: or
Carrying snow chains or equivalent snow traction devices, and fitting them when recommended by the RTA.
I am carrying a copy of the sheet and also the documentation showing that my vehicle has "manual differential lock" as it is stated in the offer to purchase from the VW dealer.
I also intend to carry a set of emergency chains that strap around the wheel but due to the front caliper running too close to the wheel (vice versa) I can only fit them to the rear wheels. Since the rear wheels will be driven under diff lock circumstances I think I have it fairly well covered as the chains are not regulated comulsory anyhow.
Interesting stuff.
Thanks again for your responses fellers. Off to the snow tomorrow.
cheers
Peter

[IN2VWS]

.....and what does the sheet say about AWD (All Wheel Drive) vehicles?
4motion is AWD, not 4WD.

[Transporter]

Thanks again for your responses fellers. Off to the snow tomorrow.
cheers
Peter

The T5 4Motion is at home on slippery surfaces, so you'll be fine. Have fun skiing!



Sent from my Galaxy Tab using Tapatalk.

[Tornado]

Hi pjondeck hope you have a good trip. Sounds like you are coveered for all circumstances.

If you recieve attention from the boys in blue. Try "yes sir" rather than pulling out the piece of paper and taking on his/her authority. A $300 fine and 3 points for disobey a traffic control device hurts the hip pocket.

I know that in Victoria you must carry chains. Vehicle type means nothing. It is to do with the possiblity that weather conditions can worsen on the trip or when you wish to depart.

This thread has clarified the ASR button on the dash and I must say thanks for starting the thread and thanks to Sunny43.5 for the information.

Have a good trip..

[4wheels]

Hi Peter,
You seem to be still not completely clear on the diff lock operation (or maybe I'm reading you wrong). With 4Motion you have drive to the rear axle whenever there is slippage between front and rear, modulated automatically by the Haldex coupling. The diff-lock does not have to be activated. The diff-lock only counteracts slippage between the left and right rear wheels, and may actually be counter-productive on flat windy roads (even though slippery), as it tends to drive you straight ahead (not nearly as much as a front (mechanical) diff-lock). I'd recommend only engaging it as a last resort, or where you know that the road contour is going to cause you to lift a wheel.

And to IN2VWS, I think AWD (at least the 4Motion/Syncro version) is superior to 4WD, as it is 4WD whenever required, but without requiring any driver input. Only downside is no low range, but you hardly need that in the snow, or really 99% of other conditions. Mind you, I'd not like to have to convince a stroppy copper in his Landcruiser, on a cold mountain.

Brian R.

[Transporter]

The 4Motion could be superior to 4X4 but in the deep snow, you are better off with 4X4 where you can lock the center diff. The same for muddy conditions with the deep tracks. Anyway as long as you stay on the road, doesn't matter how much snow is there, with the 4Motion driving sensibly, you'll be OK.

[Cousin]

So I would then assume with 4 Motion you would have to have chains on all four wheels, as opposed to fronts only for front wheel drive
?


M

[IN2VWS]

Hi Peter,

And to IN2VWS, I think AWD (at least the 4Motion/Syncro version) is superior to 4WD, as it is 4WD whenever required, but without requiring any driver input. Only downside is no low range, but you hardly need that in the snow, or really 99% of other conditions. Mind you, I'd not like to have to convince a stroppy copper in his Landcruiser, on a cold mountain.

Brian R.

My point was not 'which is superior'. My point was that all the quotes to the rules of the snow given, referred to 4WD, with no mention of AWD.

[4wheels]

The 4Motion could be superior to 4X4 but in the deep snow, you are better off with 4X4 where you can lock the center diff. The same for muddy conditions with the deep tracks. Anyway as long as you stay on the road, doesn't matter how much snow is there, with the 4Motion driving sensibly, you'll be OK.

My understanding is that the 'centre diff' (ie Haldex, or VC in the older Syncros) locks up completely as soon as there is significant speed difference between front and rear axle speeds. I know in the Syncro that used to take about 1/6 of a turn of the loose wheel. I think it is about the same in the series 2 Haldex (T5) and even less in the series 4 (T5GP). The beauty of these couplings, as opposed to the lockable centre diff on 'old fashioned' 4WD's is that they allow (quite) limited slip, sufficient for cornering, on hard surfaces when there isn't a slipping wheel, but lock up virtually immediately when there is, and so you are always in 'all wheel drive' ready for unexpected changes in surface. That's why they are so popular in rally cars. Having previously owned (and driven hard) both a 2wd and Syncro T3, I can tell you the difference in handling, even on dry bitumen, is significant. And I've never found traction to be a limitation in the T5 4M (ground clearance is a different story), either on my Cape Yorke trip, or following the T3 Syncro enthusiasts through the mud at Bateman's Bay.

A traditional 4X4 may or may not be better in deep snow, but it will be because of the better ground clearance, or more aggressive tyres, not the center diff.

Brian R.