2.5T AWD - got a bearing sound/ whining noise underneath Topic is solved

[Blacklab467]

I listened to your sound clip about 50 times. It's definitely coming from the Bevel Gear, almost sounds like one of the bearings inside, or a right CV axle support bearing.......or the collar sleeve. Those are the only things that can make any noise in there. It still doesn't make any sense that the noise goes away when you pull the #17 fuse though.
I would remove the propshaft and drive the car and see if the sound goes away. Then I would remove the BG, reinstall the right CV axle and drive the car again and assess the sound. Those parts are going to have to come off anyway to fix whatever problem you're having. You can drive the car indefinitely without the propshaft and bevel gear while you source parts or get yourself a welded CS/ BG setup as I did.

[greffel]

This is the sound from the Haldex when rotating the right front wheel.

[greffel]

With the Haldex fuse in it's place it sounds like in the clip. With the fuse removed no bad or strange sound.
Just did a nice donut on grass and on gravel and the AWD is working just fine.
The sound is strongest from the gear stick and further forward, no bad sound in the back seat.
The bad/grinding sound starts around 60km/h and gets a little bot stronger around 80km/h

Could it be a the front Prop Shaft CV Joint that's dry/stuck?

This is what it sounds like in the cabin:

[greffel]

Removed the exhaust today to be able to remove the prop shaft and now I got two questions.

1. With all wheels are in the air I can easy stop the prop shaft from turning when my buddy is turning the front right wheel.
As soon as the left wheel is on the ground I can not stop the prop shaft, is this normal?

2. Could this be the source of the sound, if the prop shaft is supposed to be in the center it's quite saggy this support bearing ?
Just shaking with hand force it moves a lot....

[jonesg]

for my money thats shot.

[greffel]

Today I removed the exhaust and dropped the support bearing. Rotating it with the hand it feels super smooth and the rubber is quite ok.
The only thing that's "wrong" is that it's not centered. CV joint felt all nice and no play in the outgoing axle of the angle gear.

The plan was to remove the prop shaft but I did not have o good Allen key. (to big 1/2 inch or just to worn)
I think the next move will be to record sound using a mobile phone in all the suspected places.

[greffel]

Hey
Still haven't got the prop shaft loose, I have 2 bolts in the from flange that just wont unscrew. Will invest in a impact hammer soon

But with the car jacked up in all four corners the sond can bee heard both with and without AWD enabled. Still loudest with the AWD enabled.
It sounds the least from the Haldex unit and increases as I move closer to the engine. Still hard to say if it's the support bearing or bevel gear or if the prop shaft is just hitting the exhaust.

AWD enabled - Prop shaft bearing sound


AWD disabled - Prop shaft bearing sound

[greffel]

Propshaft is out and now the "fun" begins.
The bad bearing sound is completely gone, can't be heard with the car in the air or driving hard on the road (all with the Haldex fuse in its place.
Feeling the output flange in the bevel gear there is no radial och axial play, like som bad cases on Youtube.

1. Bevelgear bearings are starting to fail
2. Supportbearing on propshaft
3. Haldex/back diff

What would be a good way to pinpoint the source?
Picture of the saggy support bearing......could this be it ??

[jonesg]

knackered.
I can't imagine how much whipping that allows into the drivetrain.
Id expect, eventually, it will take the bevel output with it too.

[greffel]

So this is the problem with the bearingsound ?

Just to test it could I install 10mm shims to conter the saggy bushing ? Just to make the bearing sitt in its orginal position ?