A4 3.0TDI Quattro Auto, Huge Vibration, please help.

[gazcos]

My Audi is a 2006 3.0 TDI Quattro Auto. Its done 110K mile sand is in well looked after condition. A couple developed a vibration as you went from 30 to 50 mph. After a week or so it cleared and I thought no more about it, I figured it must have been stone in a tyre putting it out of balance or something. A couple of days ago on my way to work, about 5 minutes after I'd set off it reappeared but with a vengeance. It felt like I had 4 punctures!! Again it was present between 30 and 50 mph and it didn't seem to matter what gear I was in. I've taken it to my local Indy, APS in Brackley and they are struggling. No fault codes to give them any clues and they cant tell if its engine, missing etc or drive train. they've been under the car and cant find any play anywhere and are now saying maybe its the gearbox itself, there was talk of Dual mass flywheels but being auto I don't think my car has one. I have read that maybe new oil and filter in the box might cure this but surely there must be some way of telling which major component is failing? Please help as if I cant sort this the car is as good as scrap. Thanks

[gazcos]

Found this video on Youtube, same problem but no answer unfortunately:

https://www.youtube.com/watch?v=lT9nE1kmtho

[Rich_W]

Speed related could be wheel balancing (had any weights fall off)
Could be DMF. But box out to check
Could be engine mounts (or gearbox mount)


Unlikely to need oil change in the box. These are sealed for life and generally pretty good.

[Dr G]

Getting all 4 wheels balanced and looked at for damage/dents/cracks is an easy one to eliminate.

Mounts are fluid filled so leaks generally easy to see; does the engine rock much when revved?

There is no flywheel, you have a torque converter. Could this be in some way unbalanced? Yes, but I'm by no stretch a gearbox expert.

If it was an engine issue you would assume it would be RPM related rather than road speed related.

An issue with the prop is a possibility, is there any play in the centre bearing or wear in the joint at either end?

You could also consult the services of a ZF gearbox agent as they'll be far better placed to diagnose a gearbox or torque converter issue than a 'general' garage. Internal gearbox faults are really best left to gearbox people (even Audi don't repair these, they just replace the whole box).

[gazcos]

Hmmm, thanks everyone. Todays theory is fwd propshaft joint to gearbox. They are going to remove it to check.

[caduceus]

What was the outcome of the vibration problem?