AWD not working. Need help troubleshooting.

[men2be]

2004 xc70 124k Recently acquired. I had parked in the wet grass. I purposely accelerated hard as a test to see how the awd system worked. Well, it did not. Front tires spun and left the proof in the grass, but the rears did not. Front end began to slide down the incline I was on. I did try searching but did not find any basic steps to take to start the process of troubleshooting.
Thanks in advance for your help on this. Car runs fine, no noises from rear.

[Xheart]

I take extra precaution when working on our cars.

I would raise it on four jack-stand so wheels clear the floor.

Set the shift to Neutral, and rotate the front wheel by hand, watch the propeller shaft rotate with it. For better visibility, place small pieces of painter's tape over the length of prop shaft, i.e. portions front and rear of the center bearing. Repeat with shift in Drive.

Shift in Park would set the two front wheels rotate in opposite direction.

Do not rush and be careful.

[JRL]

Start with the above.
Then run the car in gear on jackstands (slightly over idle is fine, 1500-1800 RPM)
Don't worry about the tape or shaft
If the rear wheels are turning, even the slightest, that means look to your DEM module or pressure sensor.
If the rear wheels do not move you probably have a broken collar gear or angle gear

[RockitShip]

Start with the above.
Then run the car in gear on jackstands (slightly over idle is fine, 1500-1800 RPM)
Don't worry about the tape or shaft
If the rear wheels are turning, even the slightest, that means look to your DEM module or pressure sensor.
If the rear wheels do not move you probably have a broken collar gear or angle gear

I would like to add with the caveat that it is possible the rear drive shaft spins but the rear tires can be immobile, then there is something wrong with the haldex, such as the DEM.
No rear drive shaft spin usually = bad angle gear sleeve.

[JRL]

That's what I said

[RockitShip]

Maybe I'm splitting hairs in trying to narrow down the problem.
It is possible that the drive shaft could be spinning (without rear wheel movement) isolating the problem to the Haldex system not the angle gear. :cool:

[JRL]

Again, that's what I said.
The DEM module (and pressure sensor) are part of the Haldex system, it's pretty rare for the actual Haldex unit to have issues.

[Xheart]

A Haldex accumulating 100k over short trips will show relative wear, common maintenance item.
In addition, OP acquired it recently, we don't know what abuse it had with the set of tires.

[men2be]

Thank you all for the great info! I'll check it out and report back.

[tapanitja]

Hi gents,
I woder if we can make any conclusion of the fact there is no DIM message? caused by DEM pressure/temperature sensor or comms error as I'm familiar with.
Could it be as simple as the Haldex fuse in the rear, blown by worn out pump? If the Haldex oil / filter has not been serviced 124k migth be enough for the pump.
br Tapsa

[JRL]

AWD system does not show failure messages in a display code-
You can see a DEM module or pressure sensor failures only thru VIDA at a Volvo dealer or if you have a VIDA-DICE set up

[men2be]

How lucky I am to have the wealth of knowledge available here and the willingness for those who share this knowledge!
I can't wait to dig into this problem with the support I get here.
Thanks again...


AWD system does not show failure messages in a display code-
You can see a DEM module or pressure sensor failures only thru VIDA at a Volvo dealer or if you have a VIDA-DICE set up

[men2be]

Ok guy's, here is the update. I lifted the car and ran it in drive. No driveshaft spin! I have good mechanical skills and above average tools. Any tips or tricks before I dig in?
Hey, Thank you! Absolutely appreciated.....

[Xheart]

Ok guy's, here is the update. I lifted the car and ran it in drive. No driveshaft spin! I have good mechanical skills and above average tools. Any tips or tricks before I dig in?
Hey, Thank you! Absolutely appreciated.....

if driveshaft = propeller shaft
then no AWD

Take down the propeller-shaft for next step. see Resources for pertinent how-to.
Also read Howard's take on this.
Please do not take shortcuts and/or rush if you are taking it on.
SAFETY FIRST. You can do it with fewer F words.

[men2be]

Too funny Xheart

I will be carefull. Will anything leak out with the removal of the prop shaft?


if driveshaft = propeller shaft
then no AWD

Take down the propeller-shaft for next step. see Resources for pertinent how-to.
Also read Howard's take on this.
Please do not take shortcuts and/or rush if you are taking it on.
SAFETY FIRST. You can do it with fewer F words.

[JRL]

No

[men2be]

Any idea what this repair would cost at a dealer??

[JRL]

Broken collar gear only?
$120 or so for the gear, probably 4-5 hours labor

[RockitShip]

It took myself and a friend about 9 hours, but I took my time and also replaced the front L&R axles.
I used the method of pulling the collar off using a 3-arm puller that I rented at local auto store and cut slots (angle grinder) into the sleeve so the puller would have a good purchase.
There is also a home-made device consisting of a large (cannot remember size) socket, some washers, and a bolt, whereby it rested on the inside spline (trans side) to provide an anchor for the puller.
This method went smoothly and because there were no impact tools used on removing the sleeve, I did not induce damage to the transmission or drivetrain.
The parts are dealer only... I purchased my sleeve and M02 grease from Tasca. I also used phenolic sealer to keep water/crud out of the sleeve portion of the housing which is not isolated from the elements and used a large amount of M02 grease hoping it wasn't going to rust itself together with the spline again.... we'll see!

There's a good write up on Swedespeed, which covers the entire procedure. :cool:

[RockitShip]

Too funny Xheart

I will be carefull. Will anything leak out with the removal of the prop shaft?

Maybe a little 75W90 will come out. More importantly, make sure you somehow keep track or label exactly which bolts came from which bolt hole and that everything goes back in exactly the same order.

[men2be]

Thank you JRL and Rockitship. I wish I knew someone I could trust to do the repair. It seems more often than not, no one does things like you would. Taking care to do all of little things that are maybe not "necessary" but should be done. Example, wire brushing corrosion from bolts, using never seize, using a torque wrench (Required! but how many do?) I talked to an Indy that specializes in Volvo. At this point I do not know his work and would hate for this job to damage the transmission!

[Xheart]

Patience and following the steps would take you through.
The 6mm Hex screws would require a correct length extension. There is 25ft/lb torque on these screws, not much, but with a study hand over a wobble would help with angle.

[JRL]

You still need/should get the stored codes first (if there are any).
You may have a different issue in there

[men2be]

Good point JRL! No need for me to jump to any conclusion.


You still need/should get the stored codes first (if there are any).
You may have a different issue in there

[men2be]

Well, I stopped at an Indy and asked for a quote, assuming angle gear sleeve. He would not quote without him doing diagnosis. Does this seem right? I worry about having it torn down in his shop and getting a quote I can not live with.
He does specialize in Volvo's but is an unfriendly guy to say the least!

[Xheart]

Well, I stopped at an Indy and asked for a quote, assuming angle gear sleeve. He would not quote without him doing diagnosis. Does this seem right? I worry about having it torn down in his shop and getting a quote I can not live with.
He does specialize in Volvo's but is an unfriendly guy to say the least!

My wife used to get intimidated, not anymore.
She felt obliged to fix it there.

He will not torn it down to diagnose.
Most likely he will look around and come back to you with estimates, costs ranging from low to high.
You do not have to fix anything.

Take your car home, like that.
It should be $65 - $85 at the most, but ask first!
Likely to leave something loose if they do not get the job, causing you to panic. Lol.

[Hobie]

How to tell if collar gear only? have Indy remove and look over?