NOTE: This unit is NOT A HALDEX, it is a Borg Warner. I used the term Haldex because that is basically what we all still call it. LOL Also I have a DSG teardown video coming soon! Be sure to like this video if you like teardown goodies!!! Thanks so much
@@sharg0 yes they bought the company haldex traction systems.. very common practice.. you have numerous smaller companies with a parent company.. but the factories still have haldex traction systems above the door, still the same designers workers etc, just a new parent company.
@@scottmclean337 yes, you could, but you'd add much more stress into the transfer case, and that may blow eventually (they also fail sometimes). the smartest is to get a haldex controller, so you can choose when you want it to be permanent awd, and disengage it when you dont need it
We are Haldexrepairs in the UK, this Gen 5 haldex coupling is perfectly fine and has not failed mechanically. It is most likely to just have pump failure. The clutch is still totally good. But the most common part for coupling failure is actually the outer O ring seal on the piston you removed at 4:26 gets chewed up and leaks. That is pretty much the only thing that fails on them. Good luck! And we call it a Haldex even though its a Borgwarner Power Drive Systems G5 coupling due to licencing issues since Haldex AWD was sold to BorgW. Enjoy :)
can you get bearing kits for the differential section? i have had 2 come thro now with knackered output bearings on the drivers side. no-one has let me have a car long enough to ID the bearings. (in the UK too)
I had a outwaren pump too. I changed it to a new one and the system was totally fine. Now I have a new problem with my rear final drive. If im going between 60 to 100 kph, i get a really loud wummering noise from the back of my car. The noise is not on contact with any tirestuff or so. I think I have to replace all my bearings in the Haldex/Differential unit. Seems like that this is also a common issiu with the Haldex. I have 190000km on the clock an its a 2014 Golf 7 Variant 2.0TDI.
@@patrykkrol9433 I don't recall any play that shouldn't be there, was diagnosed with a stethoscope and running the car up to speed on a ramp, was a failed bearing for sure but no customer has yet been willing to let me have their car for a few weeks to strip and identify the bearings
Charles....Check the pressure release valve at the top of the casing where the prop shaft flange meets the clutch pack housing....to the right of the HA1 casing mark at 2:11 to 2:37 in the video. See if it is clogged with debris...let us know...if you find anything there. Debris causing it to stick open = clutch slip and overworking the pump motor... then some type of failure. Also, after replacing a pump...the relearn procedure is omitted...leading to replacement of entire rear units...that would have otherwise returned to normal function.
Pump motor failed. Clean and reassemble with new motor and ride out. Those clutch friction discs aren’t too bad. Same type of multi plate wet clutch as motorcycles use. You can dress the steel plates by polishing them with some 400 grit paper glued to a surfacing plate. I have saved many dirt bike clutches this way that were much worse.
Could we infer that the pump's failure was caused by the black debris? As if the pump's internal weren't sealed properly? Because if that's the case, the failure seems inevitable and changing the pump should be part of routine maintenance.
Interestingly when I explained what is in an automatic transmission to my Uncle once the first thing he said was that it was just motorcycles that have them. This just shows you how easy it is to be ignorant or uneducated on these things. I am not even an expert on these things but I do at least know the way that they do work. Of course once when I started my 2006 Jetta and it took around 30 seconds for the idle to go down (normal for a modern vehicle) he thought hitting the accelerator would make it go down faster but he is so old fashioned he thought it had a carburetor ROFL!! He must not realize that for quite a long time no US vehicles have ever had one of those!! Whatever you do don't let him within 50 miles of your vehicle because he doesn't understand fluid specs and would probably ruin something.
It was quite interesting to see the progression from the Mk 4's Haldex to this Haldex-type Not-A-Haldex-because-Borg-Warner-makes-it system. I was curious if the glitter was ferrous or non-ferrous as that might narrow down its origin. Also, I wonder if the pump/screen was clogged with metal debris prior to going into the shop. In any case, it seems like the pump got sad, which made the motor brushes get real spicy, hence the lovely black powder that dumped out of its housing.
My untuned 2016 MK7 Golf R w DSG had a similar failure at 30,000 miles where my car became FWD only (complete with FWD burnouts when launching the car). Unlike your failure, my dealer said they found a bunch of clutch material in the motor filter as the friction material had disintegrated away from the rings prematurely. I was told that the clutch packs weren't fully compatible with the Haldex, erm, "clutch" fluid. The entire rear diff assembly was replaced under warranty. The outgoing unit was "Rev D" found in 2015 and early 2016 DSG models, and the replacement was Rev G or H.
I've been considering getting a smaller car but I still want awd. My current car has quattro (torsen) and never really requires any service to that system so it's helpful to see how one of these haldex based systems work and what to expect. Thanks!
The lack of serviceable vehicle components and repair parts is shameful. These components were assembled and should be readily disassembled for a rebuild. The right to repair laws that are being considered, which industry is vigorously opposing, may change the repair industry, but it will be slow in coming. Example, Porsche will not rebuild a failed PDK, $20K for a replacement and they will not make parts available if you wanted to rebuild one, so your point on keeping up with the maintenance or shortening the intervals when used in severe conditions is spot on. Only problem is getting owners to actually do it. As usual, great video.
I'm kind of surprised this isn't serviceable, it's just a lighter version of a wet clutch pack that can be found in most tractors for a whole number of applications. I've had no trouble getting an overhaul kit for the under/over transmission in a 1967 Cockshutt 1750 so it seems kind of ridiculous to me that it's easier to get parts for a 55 year old tractor than it is to even try to get parts to overhaul the AWD on cars that are barely even 15 years old and only seems to need a clutch and pump.
I had a loss of rear traction on my 2015 S3 and noticed the voltage to the motor was less than half of what it is supposed to be under full load. Replaced the motor with new fluid and it’s now working correctly, pushing 11.xx volts to the rear motor. Definitely a best first step if you’re dealing with this issue as the motors can be had for
Had the same issue on my 2015 S3, noticed I had a fwd car, took it to the dealer and they replaced the pump under warranty. Happened at around 50k km (sorry, in Canada, not using miles). Car is now at 115k km, gonna service it soon.
Love these tear down vids. Just a quick request: Are you able to do a feature on the VW/Audi Twin charged 1.4 Engine? It'd be a really cool insight into what was a pretty unique concept for a mainstream drivetrain. Cheers
I definitely deep dive. I'm a (the)fleet mechanic for a tree and Landscape company, theres a lot of vehicles, and equipment. I'm currently rebuilding the fuel injection pump for our 1996 kubota excavator. Lots of yik...but I love it. My golf (that I just berid myself of) was bought when I was still in NC, and, I had a sneaking suspicion the previous owner had an accident involving the ds front.. that became brutally apparent once I moved up to Massachusetts. 3 full suspension rebuilds, swaybar bushings, and it would kick it all out of wack within a year or so. Not to mention the engine mounts got destroyed twice up here.. thats all parts tho..
It’s a hydrostatic pump with pistons on a ramp like in a lawn tractor transmission. For the pump to make pressure it needs super tight piston to bore clearance. Any wear lowers pump pressure letting the clutches slip. That’s why there is was so much brush carbon in the case. Pump is worn out.
Ford also used the Haldex system on the mk1 Kuga ( escape in the US) they were known to fail. Always caused by not having the oil changed. The small gauze filter blocks and kills the pump. Ford initially said it wasn’t a service item. However the systems were also used on Volvo cars and Landrover Freelanders. In these applications it was recommended to change the oil and clean the gauze at least every 30k miles. This helped prevent failure. My mk1 Kuga, which I still have suffered a failure at around 40k miles. I replaced the pump with an eBay item. It cost around £230. I have had the oil and filter changed every year since and have had no more problems. Service kits are available on eBay which includes a new filter and a litre of oil for around £60.
A couple of Ex VAG mechanics have independently of each other said to me that most of the time on the 5 its the pump that fails and the metal is from inside the pump. One of them said unless you never service it and kick the arse out of it the diffs last for ever. Both said the pumps are complete shite. A quick polish of the clutch plates on this one and a new pump and seals and she’ll be good to go.
IM thinking those metal shavings got between the clutches and caused them to drag tripping the computer to sense movement when it should not have any. Not serviceable totally sucks. But a day and the life of newer VWs.
Yeah this doesn't even look that bad? Seems like if the motor were replaced it might work ok again though ideally you'd want to replace the clutchpack...which probably isn't easy to get separately given the "replace the unit" repair protocol. 5th gens do seem a good bit more problematic than the 4th gen units, and interestingly the 4th gen units have a real filter, while the 5th does not. Not sure which engineer(s) decided they don't need a filter in the system, but that wasn't a good move.
My rear diff blew up at 70mph with a violent jolt (one of the tapered roller bearings obliterated itself and cracked the diff open as it did so), very soon after my Haldex oil was changed. Working theory is the specialist garage may have drained the diff accidentally (there's even a TSB about this very thing, so it must not be uncommon), given the tone sounded different after the service. I even took it back to them before it blew saying it sounded wrong, but they sent me on my way.
I have a 2008 S3 8P. This is the 2nd Haldex failing on my car. The last failure made rear wheels to lockup completely while going at 160km/h on Autobahn. I was on the left lane, had to pull to right in under 100 meters. Otherwise all the cars at the back crash from behind. Was lucky, I was able to save the car from a crash. But it gives no warning on dash, no whining sound of gears, no jerkiness. Everything seems fine, then rear wheels mechanically lock up. If it happened while I was turning at high speed, it would spin or crash at the hands of the most experienced racing driver. Nothing can disengage rear wheels. We had the same lockup in another 2018 model S3 too. I think the design required to be changed. In case of a failure, it shouldn't mechanically lock the wheels. But it happened 2 times on a 8P car, once in a 8V car. I think it may have killed many people, but it would be very hard to explain what happened after a catastrophic car crash, that your rear wheels locked up. And if the driver is living, will tell you this. But it may be hard to prove it in the court. I think Borgwarner needs to take these units back. Change the design with a safe unit. May cost billions though.
Seems like as long as someone sells replacement clutch packs, it shouldn't be a difficult rebuild. None of the gears or rest of it seemed to have any real wear or damage. Of course if no one sells those discs then your sol. I figure there is probably a minimum thickness the stack needs to be as well so if they are worn to the point that the stack isn't tall enough even cleaning and sanding the steels won't get it running again.
really interesting video, ive taken apart a few motorcycle clutches and transmissions before and this is almost exactly the same setup as some of those clutches, nice to fill in the blanks when it comes to car drivetrains
Good vid! It does seem in this case the pump motor is the cause of the failure. I've seen this type of clutch packs in a fishing boat gearbox, where it locked in gear. It was caused by the clutch plates on the input shaft wearing notches in the spline, causing the plates to lock in place so they couldn't disengage not the ideal situation in a boat!
Recently ran into this exact issue in our repair shop (albeit our clutch unit had obvious clutch pack pieces in the oil). Unfortunately, I had to get into a heated argument with my colleague (VAG tech of 12 years) who was absolutely convinced that the AWD clutch pack was the exact same as a mechatronic limited slip diff. Needless to say, our relationship has become slightly soured...
Only question: Why did you keep looking to your right? I've never noticed you do that before in your vids. Something burning on the stove? Haha... Cool vid, as always, Charles!
I feel like Gen2 and Gen4 Haldex have much lesser problems because they have a separate fluid filter traps all friction discs' debris before it get into the motor.
I had my rear diff go out on my 19 Sportwagen with 37k. Strong smell of gear oil but no leaks. Rear wheels locked up. They replaced the whole rear. They said the Haldex was fine. About $6k. Under warranty
As a diy, It might be worth a shot to strip it down flush it out and throw a motor on it, curious how long it would last if you just threw a motor on it and a flush
Question: If this unit came from from a shop that did some prelim trouble shooting, wouldn't they have drained the fluids themselves? This implies that some of the loose stuff would have been drained out and lost for this tear down. Second: What was the carbon looking stuff poured out of the motor housing? Seems the options are ground up brush material or the motor windings overheated enough to bake the insulation off the windings. Seems like the only way to grind up the brushes would be to have something come loose that allowed the brushes to continue to make contact with the commutator, allowing the motor to keep spinning, until there was no longer enough material to allow sufficient contact.
Charles, what caused this failure? Lack of maintenance, incorrect fluid or a leak? Or did that little electric pump fail? I just want to know to so I can avoid this problem.
I have a potential topic for you: VW always had such a good reputation for quality. Something happened around ten years ago, I'm assuming cost cuts to increase margins, and every single time I hear from a VW owner, they have a major malfunction. Engine swap at like 40k km, broken ac, gear box etc. Is this a legit issue and more importantly; why? Mercedes went through something similar around 2004 I think, but they managed to reverse it.
@@HumbleMechanic Regardless, I have extended warranty which I am happy about. But I saw a video of one guy who took apart the diff and the tapered roller bearing is pitted to hell. Some guy in the comments said the bearing on the right side is the weak link. I think it's smaller. It then makes me wonder how these newer cars with the drift mode will last... Lot more side load...
Can these units be bought rebuilt? This is just like a transmission and differential on any other car. I can't see why these units would not be rebuildable
Hey Charles, Enjoyed the autopsy! Two questions. How much hp/tq can one of those units handle? Is there a high performance aftermarket for that unit? Thanks.
PRODIGY HumbleMechanic Loved it From the start to finish Thank you very much HumbleMechanic Take care and have a great day HumbleMechanic From Nick Ayivor from London England UK 🇬🇧
I'd just like to interject-- you keep saying Haldex, but technically the correct terminology is GNU/Haldex. I've taken to actually referring to it as GNU plus Haldex.
This is the gen 5 Haldex (Borgwarner). I think you dont see a lot of problems on gen4 haldex like on a Golf R MK6 ! Do you think Gen 4 Haldex are better unit ?
If its just clutch failure from more power then the need is probably just parts and a thicker or tighter tolerance. Or better parts to factory tolerance. Couple hundred dollars worth maybe.
@@garyhowe88 NICE! I haven't really looked into it. glad to know there are companies getting it done. Its probably a somewhat common part in the automotive world.
Pos me on this VW unit. It appears that it would be possible to add a mechanical shaft directly to the rear and do away with the clutch mecha? If not, why not? TIA my brother!
There is no reason for any of those parts not to be available to rebuild the unit. How many motorcycles would be binned, if you couldn't change the clutch...
''it's trash anyway'' Why don't you just clean the metal discs and replace the motor? Or it's probably what you gonna do but not gonna tell anybody and keep this unit for when your car fails. Clever!
So how does it control the level of clutch slip? 😮 Does it just pump oil into the clutch housing to press the disks together and controlls it via how much oil pressure there is?
Great video, as expected. Questions... {a} Can/should one throw a LSD in the gearbox you dissected (during a total upgrade)? {b} The pump in the clean side failed. Wouldn't/mightn't that have accounted for the metal in the clutch pack?
Im in the market for a Golf R, but most of what I find doesn’t have any records of the Haldex service, is that something that I should stay away from? Most of the ones I find have 80-95k miles in them and no Haldex service. Or will I be better off with a GTI instead of a golf R. I don’t plan on tracking the car or tuning it in any way.
I drive Tiguan 2013. 2.0 TDI (CFFB engine) 4Motion DSG. Until now (before me) it was serviced in unofficial service shop but I'm planning visit to official service soon. In last service check of the car my current mechanic said to me that he feels to much play in drive shaft coming to rear Haldex (it is about 10 degrees of rotation). He don't repair Haldex part of the car but he think that so much free play is not good. Is this normal or is it a problem and what could be the problem?
I have a suspect, that in Haldex gen V, they put different gear ratios between rear differential and front one. This help car to feel more "RWD" , but the Haldex coupler is constantly in 'motion' and clutch pack drag all the time. This for sure will cause exesive disk wear. THAT'S WAY I need info rear diff ratio and front diff ratio \(''/)/
So is it safe to assume that the clutch discs further down the unit were deprived of fresh fluid ? Causing too much friction which then caused the discs to slightly warp/damage ? What is your opinion on why exactly the unit failed ?. Thanks :)
Ohhhhhh man, I remember when mine went........ Pump wasn't serviced by the previous owner, filter basket was clogged badly...... Such terrible terrible noises...... I bought a Ford. I can't say that its much better, but ground clearance and a traditional rear diff and transfer case lets me sleep easier at night.....
So with you owning a Golf R with this setup, I’m curious what are your plans to try and mitigate this issue on your own cars? Just doing regular service on it?
All that expense, and it was just a motor. Seems like a clean up and a new motor and it would be good to go as a nice spare. This is why I do my own repairs! Were the clutches truly dead, probably makes more sense to just make a "spool" out of it (lock input/output) and make it full time AWD and skip the stupidly expensive repair. BTW, in vagcom, you can increase the clutch pressure (by default its set on medium IIRC on the S3) and make it noticeably more rear engage-y.
Possible. its always a balance of making a repair, and doing the most right by the customer. A rebuild might have gotten it done, but it may not have leaving the customer paying a bunch of money for a car that is in the same place it was before.
@@HumbleMechanic Yeah, I guess my "trade-offs" are as an owner, not as a shop. As a shop your reputation is worth more than an expensive repair, so it makes sense to err on the side of "known good" as any rework will do more harm than the good done from a less costly, but not 100% sure repair. I get it. Its just my personal calculus.
@@HumbleMechanic If facing a 4WD unit replacement, and it's not an obvious problem, perhaps it's worth springing for a new Borg Warner haldex pump (c.$200) before going the whole hog?
Wouldn't it be better if VW/Audi just change the service interval? And if your car is tuned, does the supplier (APR for example), recommend more frequent service? Good tutorial.
