A6 Gearbox whine
Discussion
Don't know whether anyone has experienced similar and may know the cause?
I've recently bought an A6 Avant, 1.9 tdi 130 6 speed on 52 plate. Great car, which has a surprising turn of pace, and suits our needs pretty damn well right now, but it has an annoying gearbox whine.
Typically manifests itself on small throttle openings at low revs in the higher gears (4/5/6), although some days are worse than others. Putting the clutch in or coming fully off the throttle whilst crusing (and leaving clutch un-pressed) makes the noise cease, but when you push the throttle the whine comes back again.
She's covered 164,500 miles, and seems very fit in all other respects - company owned, and covering 40k a year for the first 3 years, and has been serviced by an Audi main-dealer on the long-life services every 20k miles, with 2 cam-belt changes so far. Nothing to indicate any neglect or a hard-life, and annoyingly I didn't pick-up the whine when test-driving...
I've covered 2.5k miles in the last month, and enjoy the car, but the whine is starting to grate - anyone know what it is or how to fix? My first thoughts had been driveshaft? Or low on oil in the gearbox itself? My old 911 used to whine like this, but it was 35 years old so only to be expected!
Cheers,
Tim
I've recently bought an A6 Avant, 1.9 tdi 130 6 speed on 52 plate. Great car, which has a surprising turn of pace, and suits our needs pretty damn well right now, but it has an annoying gearbox whine.
Typically manifests itself on small throttle openings at low revs in the higher gears (4/5/6), although some days are worse than others. Putting the clutch in or coming fully off the throttle whilst crusing (and leaving clutch un-pressed) makes the noise cease, but when you push the throttle the whine comes back again.
She's covered 164,500 miles, and seems very fit in all other respects - company owned, and covering 40k a year for the first 3 years, and has been serviced by an Audi main-dealer on the long-life services every 20k miles, with 2 cam-belt changes so far. Nothing to indicate any neglect or a hard-life, and annoyingly I didn't pick-up the whine when test-driving...
I've covered 2.5k miles in the last month, and enjoy the car, but the whine is starting to grate - anyone know what it is or how to fix? My first thoughts had been driveshaft? Or low on oil in the gearbox itself? My old 911 used to whine like this, but it was 35 years old so only to be expected!
Cheers,
Tim
Accept the point that it may be that something is worn out because of the mileage, but I'm trying to get an understanding of what that might be...
Thing that gets me is the fact that it can be in gear and moving at normal speed with no noise with throttle closed, only to bring back whine with throttle opened again.
Sounds like the kind of noise you get from race cars because of straight cut gears, but obviously can't be that as a cause...
Assume its the same box as in the golf/passat/A4 tdi 130 with the 6 speed?
Thing that gets me is the fact that it can be in gear and moving at normal speed with no noise with throttle closed, only to bring back whine with throttle opened again.
Sounds like the kind of noise you get from race cars because of straight cut gears, but obviously can't be that as a cause...
Assume its the same box as in the golf/passat/A4 tdi 130 with the 6 speed?
Whines aren't typical of driveshaft problems; usually that manifests as a clunking when turning at full lock.
Noise will depend on the load on the gearbox. The shafts are pushed different ways depending on whether you are accelerating, decelerating or coasting. This alters which bearings are taking the load and can change the contact patches between the teeth on the cogs which will then make more or less noise. Worst case a bearing is failing or the hard surface on the cogs is breaking up. Driveshaft bearings are also a possible cause, if by wearing they allow the differential to move and change the mesh pattern of the final drive pinion.
Either way there's not much you can do cheaply to a gearbox except change the oil, as taking it out and opening it up takes so long, even if the problem is simple.
If you can drain the old oil into a clean container, and there is metal or other muck in it then someone familiar with the 'box may be able to work out which part is wearing from that.
AdrianR
Noise will depend on the load on the gearbox. The shafts are pushed different ways depending on whether you are accelerating, decelerating or coasting. This alters which bearings are taking the load and can change the contact patches between the teeth on the cogs which will then make more or less noise. Worst case a bearing is failing or the hard surface on the cogs is breaking up. Driveshaft bearings are also a possible cause, if by wearing they allow the differential to move and change the mesh pattern of the final drive pinion.
Either way there's not much you can do cheaply to a gearbox except change the oil, as taking it out and opening it up takes so long, even if the problem is simple.
If you can drain the old oil into a clean container, and there is metal or other muck in it then someone familiar with the 'box may be able to work out which part is wearing from that.
AdrianR
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