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?
Car will not move, this can't be done without looking the center diff.
R50 R50 Biscay Blue, Had V10 TDi with everything,AUDI Allroad 2.7T Chipped sold, Audi TT Quattro TDi , BMW R1200GSW.
WOW, I have this EXACT PROBLEM, and then some HELP!
I have a 2004 w/59k. V-6 4motion and I have 2 issues. I definitely have the humming noise, and I agree with the above thread regarding higher speeds making it louder.....whilst slowly accelerating at high speeds the noise kind of goes away... until I let up on the gas a bit then the noise comes back right away. It seemed like a bearing noise to me at first, but the noise did not go away as they should while taking sharp turns in either direction, so I didnt think it was the front bearing. The other HORRIBLE issue: once it warms up after ten minutes of driving, at very low speeds when I turn the steering wheel in either direction all the way, theres a nasty popping/banging noise in the front and the whole car jerks and tugs as if its being jolted with every pop that I hear. I can feel it in the steering wheel, it just feels like the front end is going to break away... once I come out of the turn though, it goes away. Happens in both low gears, high gears. Only once it warms up. I had someone say it may be the differential motor, which is 500 bucks or more for the part alone...
Are these 2 separate issues??? Why is it only when it warms up?
Bexter ...you're issue is definately the stepper motor. This is a known problem on earlier tregs. A new motor and ecu upgrade (under drivers seat in uk) cures this. When I took mine in to the dealers and discussed all the stuff I'd read about as possible causes of my cars problems he described your symptoms above, classic jerking and pulling at low speed turns. In the UK a stepper motor change and flash cost me £400. The stepper motor can be clearly seen under the car. 5 bolts to fit, engages a splined shaft which operates a wet clutch inside the transfer case.
On a separate point, I have heard you can run the car without a front prop as someone suggested earlier. There would be no oil leaks but it would it would probably play havoc with the ABS sensors and light the dash up like Blackpool pleasure beach.
Finally placed microphones on all the running gear (front hub carriers, front diff, rear diff, transfer box) - found that the front diff was x10 louder than the rear, in all other respects the noises were fine. I then placed the clamps at three points on the front diff and quickly identified the problem as being the right hand flange of the diff (not the one on the extended leg). Sounded like a machine gun firing through the headphones! Removed the front right driveshaft to find the flange moves laterally about 5 mm and axially as well. In the UK VW quote £2062 = VAT for a new diff, no-one seems particularly interested in reconditioning them. Trying to get hold of a second hand V10 diff in the UK is almost impossible. Readers will know that all touaregs share the same running gear with the exception of the diff where the ratios are obviously different. I have finally odered a second hand low mileage diff from a familiar auction site (from Germany). By the time I have finished I will have swapped almost all the running gear on the car trying to locate the problem - should have bought the microphone set first !
Swapped front diff yesterday. Took me 12 hours all in. Started by locking air suspension in jack mode and placing car on four axle stands, 2 at the back and two just forward of the centre of the car to give room to move. supported the weight of the engine and gearbox by placing a large hydraulic jack under the auto box.
Undid the universal joint knuckle from the steering column and the four main subframe bolts which bolt directly in to the chassis. removed one lower leg bolt on the left side, both upper wishbone knuckles which allows the subframe to sag by about 10 inch. Undid the three main securing bolts and the 18 double six splined bolts. Found there was then just enough room to ease the old diff out. Replacement was a straight reversal although the diff is quite heavy and took some manoevring when you are laid on your back under the car.
Out of curiosity I stripped the old diff to find the only problem was a worn bearing on the input shaft side. The side bearings, crown and pinions and planetary gears were all fine. And yes this finally cured the problem, no more paranoia listening for that horrendous humming and vibration at speed!!
Any idea what caused the bearing failure? Any signs of moisture? You should fix that diff and keep it for a spare...
Glad you got sorted. I have a funny "clicking" noise coming from my front drive and even though the symptom (noise) is different to what you guys experience, I've narrowed it down to either the diff or the front propshaft.
It only happens with me on a 35į+ incline, which even my (often used off-road) Treg seldom sees, so I'll live with it for now and have a look at it early next year.
Relocated to Aus. Starting fresh.
it appears to be the rollers and cage separating possibly due to a lack of lubrication at the input flange end. When I originally drained the old diff I would say it had maybe 0.6 litres of oil instead of the recomended 1.0 litres so I would recomend anyone to check their levels. If I could recomend one thing to anyone it would be to invest in a set of listening microphones. Alba manufacture them, I bought a set off ebay for £80, never seen them since....everybody wants to use them!!
Nothing on floor or on plastic floor cover but this car was 4 year old when I bought it with 42 000 miles on the clock and you assume it was filled correctly on assembly. Trying to fill the diff in situ is an exercise in itself....