Haldex AWD Diagnosis/ Repair

[- Pete -]

BG is not difficult to remove. Couple somersaults & it comes out without removing anything else...Edit, except of course the passenger side CV axle & a few other easy pieces.

The biggest problem people encounter is the driveshaft CVJ’s removal from the 2 flanges.

Between the splines on the input shaft & the output side of the CS, as well as the ring gear & pinion, yes, there will be a minuscule amount of slop. Your focus is now the DEM pump, seeing as you’ve bypassed the DEM by applying voltage directly to the pump.
If no life present with voltage applied it’s kah-poot. There’s no telling (now) if rebuilding will breath new life into its windings. It’s a slippery slope. But a rebuild kit is fortunately inexpensive.

There are non-genuine pumps available (of which seem to have good reviews) for much less than OEM. I’ve been tempted several times, never had the guts to try it given all the labor involved to change one out.

[Blacklab467]

Today I got the New pump in and filter and put fresh fluid in the Haldex. I will reinstall the propshaft in the next few days when I get time.
I also cleaned and repacked the propshaft CV's and inspected the support bearing. Didn't have any trouble removing the shaft with the exhaust dropped and supported, flange came off the Haldex without trouble also. It takes a bit of creativity to torque the flange nut though!
I removed the bevel gear for cleaning and inspection, it comes out really easy with 5 bolts. I did find that the input splines have the typical wear that people find when the collar sleeve fails. It is holding the propshaft now but I wonder if when the rear wheels start demanding torque how long it will last. It is now on my list to scour the auto wreckers and source out a better bevel gear for future replacement.
One question: does the Haldex pump come on with the key on or engine running? I tried to hear it in both scenarios but couldn't. I'm going to try and find a flowchart or see if it is getting a 12V signal from the DEM. Does anyone know how to do this? I did not remove the DEM for inspection when I installed the New pump and fluid/filter.
Thanks!

[XC70Rider]

Yes the DEM does apply 12V to the pump for testing when you start the car. I had a friend start the wagon while I had the voltmeter needles inserted to the pump connector pins.

[Blacklab467]

Thanks, I'll make sure that works tomorrow!

[Blacklab467]

Ok, I didn't have voltmeter needles and couldn't get my voltmeter terminals into the pump wiring but I put my finger on the pump and could faintly feel the pump running, It's really hard to tell and it's very quiet but I'm about 80% sure its working.

[- Pete -]

If in doubt, just apply 12v to it manually with a small battery so you can hear if it is operational & also so you know what type of pump sound to be listening for (say, if your engine was running & you were trying to hear the pump).