I have a 2004 V6 Treg 75000k, i have owned it for the past 3 years and it's been just fine apart from the odd little problem here and there.... then the dreaded road noise started about 2000k ago and seems to be getting worse. I have read loads of threads, explaining that it is normally the drive shaft bearings that have gone and that most people change the whole shaft and the problem goes away. So i was ready to expect a $1-2k bill when it went into the dealer this week. The noise is worse than before, starts about 20mph, bad at 60mph, noise gets a little better when i give it slight gas, noise gets worse when i coast down the road.
THE BAD NEWS:: the dealer has told me that the whole front differential needs to be changed and that the noise isn't the drive shafts, and that they see tiny metal shards in the fluid. They are estimating between $5k - $6k. I'm not an expert, and i have tried to research as much as i can, but don't see much info on front diff's apart from people talking about off-roading.
I'd be so greatful if some of you guys that know more out there have any comments, so i can challange the dealer. (is it a long shot to ask VW warranty for help).
Couple of guys on here and I have the same problem. I've been getting a round around, supposedly they "Can't hear the noise", the other gentleman was able to get the transfer case replaced but that didn't cure it.
One suggestion i have been given from a non VW user was, to disconnect the front driveshaft to just test if the noise is still there, essentially making the car 2wd. I know this can be done on other makes but on the VW will it break any seals? Anyone know if this is possible?
This is crazy! I just came here to search for this exact problem.
Must be a temperature vs elastomer related problem.
Mine started humming about 2 weeks ago when the temperature dropped to 60-70F during the day.
Old V6 #022093 Basic, New V8 #002223 Gone.
Current vehicle 2008 Q7 S-Line v8 Loaded.
becareful those symptoms can be caused by a 'bad tyre' or slighty buckled wheel,
VERY rarely will you get any feedback through the steering wheel from a faulty front differential until its is just about totally gone.
I have 2004 V10 which I bought 1 year ago and has the same problem, a low hum groaning from 45 - 65 mph and an intermittent knocking especially when cold at low speed which comes from the drive tunnel. I have swapped the rear propshaft as I originally thought it was the centre bearing (not the famous carrier bearing as this was ok) - if you ever remove the rear prop it feels as though the centre bearing "sticks" around the joint, but I found to my cost that they are designed like that from new. By the way if you live in the UK, don't ever buy from VW they are £570 + vat, if you're prepared to wait a month you can buy direct from GKN (who manufacture for VW) for £350 + VAT.
This did not cure the problem so I sourced a recon transfer box and brand new stepper motor. When I changed the transfer box - not a massive job and no need to remove the drive tunnel from inside the car (carefully lower the gearbox on a hydraulic jack untill you can get to the upper gearbox bolts) several ball bearings dropped out of the CV joint on the end of the front prop so I swapped this aswell.
Result - no change, still same humming etc. I did change the oil on the front diff to see what that looked like and there was metallic slick in the oil. I have swapped the tyres front to back but that made no difference. I have had a mechanic from VW look at it and he suggested everything I have done but also thought it could be a front wheel bearing. I have just ordered a set of rattle detector microphones. Having eliminated everything else it can only be the front diff, a front driveshaft or a bearing. When I do find out I'll post the result on here.