nasty noise V70AWD

[BenAWD-R]

Hi guys. im expecting the worst on this. i wouldnt be suprised if its on its way out. if i reverse on a lock..doesnt matter which way. i get a one off CLONK from the front. doesnt do it when i go forward again... but will every time you go backwards on a lock.(well i im pretty sure its from the front). it doesnt sound overly healthy. its not got any nasty whines. altho it wouldnt suprise me if the oil hadnt ever been changed i did wonder if it was a loading thing as there is no centre diff as such....but it wouldnt shock me if somethings buggered under there.

checked the prop joints, cv joints. all the usual suspects..just wanted some further opinion.

any ideas?
Thanks in advance

Ben.

[Filterlab]

At what speeds does it whine? It could be something as innocent as a knackered wheel bearing, in some cases the bearing housing can clonk when subjected to direction change.

[BenAWD-R]

low speed under 5mph it only does it under change of direction and under load..i.e 75% steering lock and going backwards, ill check later if it does it going straight backwards. everything else seems fine. definately transmits drive. its just that nasty noise..if its normal ill leave well alone. its been like it since i got it. just need to make sure its not about to poke bits out of the casings.

[BenAWD-R]

ooops missed a bit out. whining was at low ish speeds..got alot better when i changed the gearbox oil but not totally gone when cold..seems alright when it warms up a little couldnt find a mini pump to pump the transfer box and rear diff out..it needs doing the rear diff was like liquid chocolate.

[Charmie86]

check the prop center bearing mine when and was doing that, mine was knackered and need changing

[v70rade]

This may seem like an 'odd-ball' reply! - But have you had a 'full' four wheel laser geometry check done on the car? - The reason I ask is that over the four years I've had mine, if the front track, caster, camber etc are 'slightly' out of limits I get a single loud bang? (or clunk) from the front of the transmission when reversing on full lock. This noise only occurs in the following situations: -

Geometry out of alignment (only by a degree or so on the tracking) or Turning at full lock on very un-even ground.

If it's the same as mine, you can 'feel' the noise through your left foot if rested against the centre tunnel.

I've attributed it to the geometry of the front drive shafts in relation to the position of the hubs at full lock.

Should add, check all of your tyre pressures / tread as well, the slightest diferential will cause a low speed whine.

Always worth treating the awd system to some new oil anyway.

Good luck.