Greetings all!
I am hoping someone here can assist with troubleshooting a problem that popped up today. While driving the 2004 XC70 AWD auto-trans along at highway speed, there was a noise like a clunk and the vehicle lost drive power. At first, it moved slightly under its own power, but now nothing. No engine or transmission codes, the transmission fluid appears to be at the proper level, and the gear indicator on the dash shows proper gear selection (P, D, N, R, as well as 1, 2, 3 with the manual selection), but the car won't move even after cooling off for several hours. There are some slight (normal?) sounds from under the vehicle upon shifting gears, but it does make a bit of a grinding noise when shifted into reverse. The kicker for me is that when I got it completely up on jack stands and tried again putting it in gear, the rear wheels move (drive and reverse and increase velocity when manually placed in a higher gear), but the front wheels don't even try.

Does anyone here have suggestions on what might have happened or what I should check?
Thanks!

 

Have the front axles been replaced yet? Particularly the right one?

If the center bearing on the right crappy aftermarket axle walks down the shaft - the right axle pulls out of the trans - and the car won't move (the transmission sends power to the wheel with the least traction, that's what a normal differential does) and will grind when shifting because the transmission is shifting and spinning but the right axle has popped out -

Remove the carrier for the right axle center bearing and make sure the axle is pressed into the transmission all the way - then push/hammer/press the bearing back into place and stake it down.

On a 2004 the haldex system should pick up that the front is spinning faster than the rear and engage the rear wheels - so I suspect the haldex system is not working either - which would be common on a car that age.

 

Thank you for the quick response hoonk! I will check the front axles tomorrow to ensure they are both seated and report back if the problem is solved. I did try yanking on the axles a bit when I got the car lifted and they seemed secure, but that was just a quick check.

Also odd, the back wheels do respond as expected by turning in the opposite direction when one is spun, but the front wheels act as if they are connected to nothing. Perhaps that is another indication that one of the axles has popped loose.

 

If the driveshaft is stationary that's the spider gears in the differential doing what they do - if the front does not do that with the car in park - either the spider gears have exploded in the front diff (very unlikely if it does not sound like a rock crusher) or one of the front axles is not plugged in all the way.

 

An easy way to tell if a front axle is unplugged - the car will roll in park with the parking brake off -

 

alright, hoonk, you were correct! It was the right axle and it had slipped out a bit as the bearing slid down the shaft. Now I'm off to find the best way to keep that from happening again soon. Thanks a ton!

 

Press/tap with a hammer carefully (using a punch or chisel on the inner race only) the bearing back into position and stake the axle shaft - use a hammer and a punch to dimple the axle so the bearing can't/won't slide down the axle again.

 

Stupid follow-up question... Where should I stake the axle? In the hub? I can't picture how to divot the axle to keep the bearing from moving again.

 

The axle is too small in diameter (sure by ~002 inches) where the bearing is - allowing the bearing to move/slide. Make the axle bigger right where the bearing is trying to come off - A punch will raise/move a little bit of metal, do that a few times around the axle and the bearing can't move anymore. You don't even need to remove the axle.

 

got it - that makes sense. Thanks again and I'll get to work on that now!

 

Seems to have done the trick. The axle may look closer to a golf ball in places now, but the bearing no longer wants to move more than about 1/8 of an inch. Should keep it engaged now.

Should anyone else have a similar issue, hoonk is a heck of a problem solver!

 

A year later and this just saved me from actually towing mine to a shop!
Mine popped out but evidently still had enough friction for the front wheels to behave correctly when they were off the ground but they would not engage when they were on the pavement. The PO took exceptional care of this car - $1,000 set of newish Michelins on a car with 230K miles on it is always a good sign- so I doubt they would put a cheap axle on it.
My question is: Could the bearing be worn from age and should I just plan on replacing the axle soon?

 

The factory rf axle costs about $600, the oem GKN brand can be had for about 300.

Other aftermarket axles can be bought for $100.

$1200 versus $200 (plus labor) for 2 axles on a 230,000 mile car. Which would you choose?

I've never seen the bearing move down the shaft on a factory (or GKN) axle.

 

Looks like someone already fixed this once using your trick!
So it was off to the parts store for a new one.
Simple install with the exception of the inevitable strut bolt that didn't want to break loose.
I bought the car for my teenage daughters to drive but of course they didn't want to wait for me to finish and took off in my 2012.
After an extensive test drive I have to say I still like the P2. It just feels so solid.