Gotta AWD with HALDEX?!?- Here's a tip:
 

A "Do as I say, not as I did..." thread.
I own a volvo xc70 with AWD and recently learned of a little known secret that can affect high mileage cars equipped with haldex AWD systems. HALDEX systems aren't just used on volvos, but evidently a number of other makes such as Ford and such.

Haldex Traction - Wikipedia, the free encyclopedia

I read a secret blog somewhere and learned the Haldex AWD system has it's own oil filter, which my dealer didn't even know about. After about 100,000 miles or so, the filter becomes clogged, and the oil pump cannot activate the viscous clutch for the AWD so basically the AWD doesn't work and the car is left with 2wd only.

I bought the filter this summer, planning on replacing it as preventative maintenance. This winter, I noticed my rear wheels were NOT activating when the front wheels spun, so I got under the car today. removed the old filter. It was COMPLETELY CLOGGED! I am hoping that the pump is not burnt out.

So basically, if you have a higher mileage AWD car with Haldex, check to see if you have an accessory filter in the HALDEX system. Go buy one (cheap) and enjoy your new weekend project:D

The filter on the left was completely clogged- I could not blow through it. The filter on the right is the new one- it is easy to blow through. Now let's see if this works!
http://forums.pelicanparts.com/uploa...1419964035.jpg

Please let us know if this worked out...

Also, where is this filter on that vehicle?

angela

Wow -- good info, thanks!

I believe that Audi recommends fluid and filter change every 40K miles on Quattro TT Haldex, but have also read that 20K miles is the way to go due to the somewhat fragile nature of the system.

volvo is more lenient on their prescribed fluid and filter changes than vw / audi is. General rule of thumb however is I replace the fluid and filter every 30k miles.

Well, an update, it's still not fixed.
Evidently, what happens is that the filter gets clogged, that causes the pump to build resistance/ fail, which backfeeds into the DEM computer and the computer blows.

I should have changed it sooner. No- I should have known it was there and changed it 80,000 miles ago. In the future when I create a time machine, I can go back and read this thread and remind myself to change it before it ever fails.

I hate my life :mad::mad::mad::mad::mad:
Just kidding, but I'd really like to get this working before it snows!

..also Angela, the filter is located in the haldex unit on the car. In the case of the volvo, it is on the front of the rear differential case where the driveshaft connects into the differential housing. Although replacing the filter is simple in theory, like all worthy car projects, it becomes a cursing spree because there is no room to work. If you have a volvo and want more detailed stuff, let me know and I can post pics.

Ron

There could be a number of problems causing the Haldex to not work; you really need to plug in to a DICE reader to see how the modules are communicating and what they are reading. I picked up one of the knock-off units from e-bay.

I just had the DEM for my v70r repaired by Xemodex in Canada. They turned it around pretty quickly (sent it out on Friday and got it back Tuesday) Give them a call and talk to someone in tech support; they have a DEM testing flowchart they can send to to help eliminate any other possible causes.

^^^Thanks,
I really am getting to the point where I need a reader. Is a DICE reader a type of reader or specific brand? Basically- please point me to a link or something where I can throw some credit card info their way! I'm having some MAF issues also. At 150,000K stuff is going to happen. ( I need to go research this myself but my wife is cooking dinner and I'm sitting here typing!)

Yeah- I agree. I am scheduled to have the car read next week at my indie. There are some other issues I need to sort out as well.

As for the haldex, The bevel gear is good, the pump works with 12v, but I have not checked for resistance or flow. There is power to the DEM. I have a spare rear haldex (two actually-imagine that ;) )and replaced the filter, pressure sensor, and throttle assembly. The oil is full.

What I'm going to do before I lower the car is check to see that the DEM itself is sending power to the pump. I have been trying to keep my original DEM to avoid reprogramming everything. On my other two diffs- one DEM is broken and the other is a 2002 (mine is 2005) and the 2002 (2001? maybe) has one less wire on the DEM input.

What's weird is when I jump the pump to a 12volt battery, the rear hooks up but there is no torque to the rear wheels. I can stop them with my foot. I am hoping this is the throttle assembly being incapacitated by the DEM. I don't know if that is a correct assumption or not. If it's not, then I need to either pull the driveshaft and replace the pump, or replace the whole haldex assembly.

It's also good to hear about Xemodex. I saw the name on swedespeed today and was going to call them on soon. I think we might be getting to be good friends.

I was under the impression that Volvo was owned by Ford. No?

It was back in 2005. I think...Somewhere about the time of the "great recession" volvo got sold off to a chinese company.

DICE is the Volvo specific CAN bus reader interface; it works with the Volvo VIDA software to communicate with all of the modules in the car via the OBD-2 port. There are some threads over on sweedspeed with some links (look in the FWD/AWD under the R forum); if you search for "VIDA DICE" there or on e-bay, you should come up with something. Note that the knock offs do not allow you to purchase software updates from Volvo and push them out to your car; you'll still need to pay your indie shop to do that.

There's a lot more to it that just applying pressure; the control valve has to open the proper ports to allow oil pressure into different ports in the clutch pack. This is how it controlls the amount of torque split to the rear.

If the pump is running then is should generally be OK. if you have the pressure sensor or the control valve out and run the pump, it should spew out a pretty good flow of oil; I would guess about 2-3 ounces in 15 seconds. The entire system holds about 600 ml or about 20 ounces. I just used this method to flush my haldex and replace the oil before installing the new filter and putting the re-built DEM back in.

Thanks!
I was looking for readers before the holidays and became immediately confused and overwhelmed. This really helps.

I r smarter today because of this thread. Thanks for the info.

Ford sold Volvo to Geely (chinese) in 2010.

Great. Now i've got something else to fret about on my 04 S60R with 106K miles. Just something to look into I guess. Thanks for the heads up.

A couple of pics of the rear differential http://forums.pelicanparts.com/uploa...1420151891.jpg
heres the filter location. Not the best pic but gives an idea of where it is. I had to cut an allen wrench to access this. It took 45 minutes to undo one allen bolt. I bought a regular bolt and a 8mm closed end wrench with a ratchet drive to reinstall-
http://forums.pelicanparts.com/uploa...1420151908.jpg

just an update- I FINALLY GOT THE G#$ D$#$# AWD system working on my car!!!!!:D
YES... IT took ALL winter... so just in time for spring it works..How long have I been working on this... I dunno.. I need to see the original post date on this thread..and I'm scared to look.

I replaced:
oil filter
pump
oil pressure sensor
bough vida code reader on ebay (mistakenly from china)
realizing I screwed up...
I bought vida code reader (from someone in america)
throttle body mechanism
replaced entire haldex unit.
sent dem computer to zemodex
resent dem computer to zemodex


I just got new computer back- replaced- IT WORKS!!!!! :D:D:D:D:D:D:D:D

Lessons:
1.Buy a subaru
2.Zemodex has a really good shipping policy. They sent it from canada on monday- it got to virginia on Tuesday....That- to me is impressive.

The end.

OK, I had to LOL at that one.

Congrats on getting your AWD working. Sounds like it required extensive brain surgery.

What ultimately do you think the problem was? The DEM? And was that from zemodex?

Thanks!