Failed attempt to service haldex and findings

[XC90Mk1]

I have just attempted to service the haldex unit on my 2012 xc90 and thought I would post my findings.

Firstly I followed ‘Volvo Sweden’ YouTube video this is excellent and should be a point of reference (incidentally this is a haldex 4).

There is however a significant difference to be noted with the xc90 which is that the prop shaft to haldex circular input/drive unit is much larger and deeper on the xc90. I do not know to what extent however it is visible.

I firstly went to disconnect the clips to the haldex input sensor assembly and note some questions on line with reference how to do this. The answer is to insert a small screwdriver into the square box in the middle of the connector and withdraw. One of my positive ‘click’ sections of the connector broke with minimal force. I believe this to be due to the plastic connectors being inches from the exhaust and going brittle.

I then removed the control module which is straight forward.

It is then possible to remove the right hand 4mm filter cover bolt however after an hour with various 4mm hex keys and Allen’s etc I was unable to get to the other side.

On Volvo swedens video he removed the pump and went through the left side. I can see on the 90 it would not be possible/east to remove and that more to the point the access would still not be permitted without the pump due to the size of input ring.

The Volvo has been serviced fully from me from 70k to 125k including cam belt and ATF fluid etc however this one was beyond me. I would suggest it is possible if you have either:

1 a lift. If the vehicle was above head then possibly.
2 removal of the exhaust, prop shaft and input to haldex was undertaken.

I purchased the fluid in 2018 however had a issue with the haldex that Volvo resolved under warrenty.

Accordingly the fluid is either 55,000 miles and 4 years old or 122k and 10 years old. I was going to replace the fluid and ask my mechanic to do the rest however upon using a syringe to remove a wry the oil remained hello, golden and to good quality, it was not dirty etc etc. this was a big suprise…. I will accordingly leave it 24 months and then have mechanic look at.

I have heard of others undertaking this task. I wonder if they did this on the earlier generation 3 haldex where the filter is on the side and accessible (which I would consider possible.

On Mine the haldex 4 has the filter above the prop shaft and I would argue it is not possible to do for the average home mechanic.

I would be interested to hear anyone else’s experience here. I have spent about 2.5 hours here and am quite disappointed to be fair….

[XC90Mk1]

Just to add the Volvo has been ok to work on to date, but this design is absurd (not the haldex 4 but their installation). All other manufacturers recommend frequent oil and filter changes and on the 90 it’s near impossible. I imagine the earlier 90s were designed for the haldex 3 and when the 4 was introduced simply started bolting these on….

[S60D5-185]

I've got Haldex 3 on mine so was a little unclear as to how the filter location was an issue on your Gen4 but this shows the issue clearly.

On that basis you are now in exactly the situation that I was because the Gen 3 pump is a different shape ( bigger casing ) and will not clear the flange although the filter is easier to access than yours.

I dropped the rear of the prop out of the flange and removed the flange to gain access to the pump. I was then able to clean everything and fit a new filter.
In addition, I bought a new flange oil seal from Volvo before starting the job and installed it prior to refitting the flange. It was genuine and relatively cheap from memory.

The rear prop CV joint can be tight in the flange but there is an access hole at rear which allows a little leverage to ease the CV forward and out.

I did not need to touch the exhaust or drop the prop centre carrier. It was possible on mine to wiggle it out.

Good lucj as it's worth doing.👍

+ YouTube Video

[XC90Mk1]

Originally Posted by S60D5-185

I've got Haldex 3 on mine so was a little unclear as to how the filter location was an issue on your Gen4 but this shows the issue clearly.

On that basis you are now in exactly the situation that I was because the Gen 3 pump is a different shape ( bigger casing ) and will not clear the flange although the filter is easier to access than yours.

I dropped the rear of the prop out of the flange and removed the flange to gain access to the pump. I was then able to clean everything and fit a new filter.
In addition, I bought a new flange oil seal from Volvo before starting the job and installed it prior to refitting the flange. It was genuine and relatively cheap from memory.

The rear prop CV joint can be tight in the flange but there is an access hole at rear which allows a little leverage to ease the CV forward and out.

I did not need to touch the exhaust or drop the prop centre carrier. It was possible on mine to wiggle it out.

Good lucj as it's worth doing.👍

Thanks for this post, really helpful! I think I should give it another go!

How did you remove the prop? Was it hard, looking around its not east to see how it comes out (although people seem to say it’s not that hard)…

Is it simply a case of removing the bolts/Allen heads that connect the prop to haldex flange and pushing out, or is there more to it than that?

Never removed a prop shaft in the past.

Thanks

[S60D5-185]

Exactly that.
The cv joint doesn't sit particularly deeply in the flange.
On some flanges there is a threaded hole at the back and a bolt can be wound in from the rear to push the prop from the flange.
Failing that a large exhaust u clamp can be fitted to the rear CV joint adjacent to the flange and then struck with a hammer.
Lastly, when removing the flange an impact gun is handy but if you have D5 crank locking tool this fits nicely and allows flange bolt to be loosened and tightened.👍