drone noise ?

[cpu_man]

Originally Posted by laundryman

Speed related drone=prop shaft. Had mine changed under warranty. Unplug feed to pump on rear diff and see if drone goes goes. beware car acts quite differently without power going to rear!

If I unplug the rear diff plug what will this rule out?

thought only I the rears drive when front lose grip

[Bigjimknickers]

Originally Posted by laundryman

Speed related drone=prop shaft. Had mine changed under warranty. Unplug feed to pump on rear diff and see if drone goes goes. beware car acts quite differently without power going to rear!

Hi, where is the Feed to the pump on the rear diff then?
Thanks!

[Tannaton]

Originally Posted by cpu_man

If I unplug the rear diff plug what will this rule out?

thought only I the rears drive when front lose grip

No - the prop is permanently driven, the control of power to the rear wheels is done with the AOC coupling in front of the diff.

The only way to rule it out is to remove the prop completely and then drive the car. This isn't as bad a job as it sounds

[cpu_man]

Hi guys,

So driving the car at 60mph with light foot on gas pedal the noise is there as we know and if I lift off the pedal the noise goes away.

So today 70mph and I can't really hear any noise and nice quite cab etc.

Driving at 80mph (yes private road etc) the noise is there like at 60mph but just a different tone, a little higher most likely due to speed increase, again at that speed foot off the pedal and noise goes away, slightly touch gas pedal and noise back.

It is speed related it would seem.

I see some posts on here about removing the drive shafts but if I am driving at 60mph with light foot on the gas only drive will be going FWD as the prop is always turning but just not working the back wheels, would this not rule out the prop as noise goes away once foot off pedal?

[cpu_man]

Hi guys, looks like I migit try and remove the prop shaft in the next few weeks and see if my noise goes away to help identify this noise.

Couple of questions:

1. If I remove the prop shaft is the car ok to run for a week or so with out this fitted?
Will it cause any errors or dash lights?

2. Will it cause any damage to the running gear such as diff, gegearbox etc..

[cpu_man]

Originally Posted by cpu_man

Hi guys, looks like I migit try and remove the prop shaft in the next few weeks and see if my noise goes away to help identify this noise.

Couple of questions:

1. If I remove the prop shaft is the car ok to run for a week or so with out this fitted?
Will it cause any errors or dash lights?

2. Will it cause any damage to the running gear such as diff, gegearbox etc..

Any one guys??

[john langrick]

Hi, for the first year I had mine (my03) the spline gear was stripped, so although connected, the prop shaft was not driving anything. No codes or any symptoms . As my previous car was v70 which was front wheel drive only, I knew no difference.

I am not an expert but suggest you would have no problems short term in removing prop shaft but suggest marking so you connect the mating surfaces back in same position.

I am not sure if this will identify your problem, but should indicate if it is related to rear wheels being driven.

I also suggest best do it before the snow comes!

Hope this helps

[cpu_man]

Good morning guys, ok sorry to keep dragging this up.

So I have had new tyres fitted and 4 wheel alignment carried out and the car drives like new.

The rear tyres were stepped and thought this COULD be causing the noise but it's not, its still there.

I have a little bit more information if it helps.

I notice If I am at around 60 i can hear a very faint drone, now if I take my foot off the gas the noise will go away (as we know) but if I very very gently place my foot on the gas the noise will come back but there is like a 1 or 2 sec delay every time?

Does this help in any way?

If the AWD system in use at 60mph with no wheel slip?

[john langrick]

Hi, just how noisy if your drive train.

Mine xc90 is much older than yours, and a lot more miles (170k), but if I listen very carefully I can also hear a very slight drone noise. This happened before and after my awd was fixed (spline gear and transfer box).

I can only hear it if the radio is off and the noise does match your symptoms.

But I know the noise is no more/Les than I hear on friends other makes of 4wd or and. So I just take it as part of the 'engine/ drive train noise

My point being, are you being a bit critical?, perhaps some noise is normal.

Cheers john l'

[trumpetdropper]

Hi Guys

Looks like I might be experiencing a similar problem with my 05 T6 (@90k)
slight droning noise between 50 & 70 whilst under positive throttle.
Started a couple of weeks ago - new tyres fitted & tracked about six months ago so not ready for a change.
Immediate thought was wheel bearing but couldn't feel/hear anything when rotating etc each wheel.
Slight prickle about the gearbox, but all gears work and change smoothly (did a partial fluid change about 9 months ago - preventative measure)
Did wonder about the haldex and plan to do a service on this over the holidays if the weather is reasonable, and will check prop at same time.
I did notice this morning there is now a very slight vibration that can be felt through the floor especially where my left foot rests - might indicate something more centrally located?
I shall watch this thread with interest.

Cheers with seasons greetings to you & yours

Andy