Having owned several generations of torsen AND Haldex cars, I can tell you that 99% of the time there's no significant difference. And for the geniuses who can't figure out why Haldex is used at all: #1 reason is fuel consumption regulations. So please stop bashing and posting nonsense.
Dunno if it is not gonna overheat if you go driffting and cause the clutch plates to start slipping instead of gripping..but it sure is quick in transfering torque and is in a way full time awd!I think I like it!
Nope - thus is NOT real full-time AWD. (See Subaru.) If it only engages rear wheels after front wheel slippage is detected, (albeit quickly enagages), it may be too late. Losing traction in many cases is a split second scenario that can be life or death. If I want real full-time AWD in bad conditions, we park our 4motion (haldex) VW and take our Subaru.
Simply put, yes that is what it does, James Bradley. But you ask if "that's all?" - and I think there's a bit more to it, so I'll try and explain. :-) The "point" or rather, "what makes it special", is that it's a further evolution on a different type of all wheel drive, than "just" applying three differentials - one on each axle, and one center differential, and then possibly making each of them lockable. The Haldex system is very light and compact, so it is applied to a much larger variety of vehicles, that can then benefit from all whell drive in - for example - snowy conditions, while they normally are just regular family cars, that aren't intended to i.e. go rock crawling or river crossing, but on the other hand would benefit from extra traction in winter. It's also different in terms of the way power is distributed between the axles. When you apply a differential, you distribute power, but you also allow the power to choose the path it wants. And the power will use the path of least resistance. So if one wheel is on ice, and the other three on tarmac, then a three-differential system with no locks will in theory be left standing, with all the power going to the one spinning wheel being on ice. That's where the locking ability comes in, but you can only lock it in a specific ratio, say 50/50 front/rear, and obviously 50/50 on each axle. That means, that if for instance you are driving up hill, and the rear axle looses traction, then the front axle has to pull the total weight of the car, but with only 50% of the power, since the other 50% are sent to the spinning rear wheels. A Haldex system is clutch based, so it can transfer power with no steps. It can run solely on the front axle, which is what it will do almost all the time. If the front looses traction, it's able to send a varying amount of power to the rear axle, typically upwards of 95-100% of the engines power. That makes it much more efficient in smaller vehicles, since you don't rely on a massive overcapacity in the engine to pull the car ahead. This change of power distribution happens very quickly, usually within less than an eight turn of a spinning wheel. Usually, Haldex systems does not incorporate lockable differentials on the axles themselves either. Instead, the cars disc brakes are used to form what's called "EDL" or "Electronic Differential Lock" (which is a marketing term for "differential lock equivelant, achieved electronically" and not to be confused with electrical actuation (command) of an actual differential lock). This uses the brakes individually on spinning wheels, and means that in theory 100% of the engine power can be sent to one wheel. This also implies that a car with three wheels on ice should be able to crawl forward - however, the management software of the system might not always detect these situations accurately, so even though the system has this capability, putting it to use might not be so easy. The reason for this is, that as the brake is applied to a spinning wheel to make it stationary, obviously it's also no longer possible to detect spin (as the wheel is not moving). Thus, to find out when the wheel has power again, it must be unbraked and allowed to either spin or grip at intervals, in order for the management software to find out, if there is traction or not. That means that these systems are often "cradling" the car along, and that they often require quite an aggresive throttle to actually operate, if you compare it to e.g. a Land Rover Discovery with differential locks and anti-stall, that you can basically take through anything without touching the throttle. What's new about this specific construction is the centrifugal pump, which allows a quicker reaction time of the actuator that drives the clutch pack. That means, that the power distribution can now happen much quicker and thus much closer to the actual demand based on e.g. spinning wheels or driver input. That should allow the system to come even closer to recognizing and acting on difficult situations correctly. Basically, as a headline, you can think of these Haldex systems as being a full offroad setup with front, center and rear differential that all are lockable, only achieved through various electronic gadgetry in order to get the "same" potential out of a much smaller platform (i.e. a Volkswagen Golf rather than a Jeep Grand Cherokee) and a much smaller engine (i.e. 150 HP TDI rather than 300 BHP V6/V8). When you're done picturing that, of course you then realize that all this gadgetry of course has it's own limitations, and then understand why "same" potential was in quotes. :-) But it gets a long way, considering the vehicle types and engines it can be applied to. Especially considering that a full Haldex system might weigh something like 70 kg.
Je ne sais pas quelqu'un va me répondre. Je comprend bien l'anglais mais l'écriture est plus difficile. Je possède une Octavia scout de 2015. Je tracte des remorques de bois. Il m'est déjà arrivé d'être bloqué avec les roues avant patinant et l'arrière n'avait pas assez de transfert de puissance pour me faire avancer. Les roues arrières ne poussaient donc pas et ne patinaient pas. Le poids de la remorque était bien sur l'essieu arrière. Y a-t-il moyen de programmer différemment Haldex pour qu'il y ait plus de transfert de puissance ou les roues ne patinent pas? Je pense que dans les cas difficiles Subaru est mieux!
Imam oktaviju iz 2004 god.haldeks radi prefektno,kad je isparavan on se automatski aktivira kada prednji točkovi proklizaju,uradite servis haldeks sistema i nebi trebalo imati problema.
Haldex filters need to be cleaned regularly. Haldex 5 version does not have a filter per se, but it still needs to be cleaned. If the service is not done, it is expensive. It is a good system, but not very practical.
@@harri9885I just returned from a garage where I cleaned it after the last 30000 km. It was dirty, very dirty... Fresh oil, sealing, gaskets and Haldex works smoother and quieter.
Yes if you drive hard on the haldex, even 30.000 km should be ok, not too early. Audi recommends 3 yrs on oil, nothing about cleaning. That is insane. You change the pump, and again the same story.
There’s a small mesh to capture any impurities, it requires the pump to be disassembled so most shops just replace the fluid, but you can ask for the mesh to be cleaned too. If it gets too clogged the pump fails.
shame its spoilt on vw's ( audi /porche ect ) by having a propshaft with a design flaw , time for vw to allow the center cv joints to be sold to the public and not kept in vw dealers , makes a £!00 job into £1400 , and its a flaw on the range from golf to cayenne
full time AWD you lose 7-8 miles per gallon because of weight and power distribution. my Alltrack will get 34 mpg on the highway because the AWD can shut off like this
@@Squid165 I got an AWD because I WANTED AWD. Not only for slipping wheels, also because of the feeling of an alltime AWD, especially for accelerating out of corners. I know i have a lower efficiency with my Subaru AWD, but still i prefer my Subi with 6-7l/100km compared to my older Diesel, a 1,9 TDI 1Z Golf 3 Cabrio, which is able to run with 4-5l/100km. But at all you are right, for the 0815 consumer, Haldex AWD is the way to go.
@@harrison00xXx Okay? And I bought a car with a Haldex/semi AWD because I WANTED IT? I'm not driving in environments where I'd need constant AWD so the advantages of reverting back to FWD to save fuel makes more sense.
I’d rather say it’s very simple. Just a few elements. Pump, clutch, control module, relief valve. Simple and reliable on condition of regular oil change and pump strainer clean every 30kkm.
Engineers had to go with this design as it is the most efficient in terms of space. And yes it’s a bit too complicated in my opinion. But systems like this are used when a fwd cars that are not essentially designed for (awd) is given (awd)
MrVaderino I don't understand what are you doing here, it's a video about haldex, are browsing the internet to find all other AWD systems and tell them the subaru's is the best? I can't image how empty your life is.
uhhhh... someone is getting this serious and personal! lol UNLIKE YOU, I like to see things in PERSPECTIVE and not buy the first crap they try to feed you... -But you're right: YOU CAN'T IMAGINE about my life... for your information, we design/engineer systems like this on the daily basis (thank god, not exactly haldex) so I probably know a couple of things that could "jam" your haldex clutch discs for big while... SIDE NOTE: I do NOT think that haldex is a badly designed system... it's the whole CONCEPT that's wrong!! That said, feel free to continue your BLIND love-affair with haldex....
Not for bubba trucks. This a full time system. Some torque is sent to rear all the time. For cars to give them maximum traction and fewest, if any, side effects on a daily basis when making tight turns. No reason to make driver turn knobs or pull levers to get AWD. Just push pedal and the system locks drive to rear wheels before fronts slip 1/12th of a turn.
Why? This gives the benefits of AWD traction without the efficiency penalty of full time AWD. It also puts far less strain on the rest of the transmission components during tight turning by alleviating transmission windup across the two axles. You clearly don't understand the principles of drive train operation.
