6 Speed Manual Transmission fault

[lozzyho]

Hi all

I recently changed my 2013 A6 for a 2018 2.0 TDI Ultra with a 6 speed manual transmission.

Unfortunately, not long after I bought it I noticed a noise when driving in 1st and 3rd gear. The noise is very much a growling bearing type noise, and might happen in 5th too (not sure because of the road noise in 5th).

The noise is road-speed related and only happens when those gears are actually engaged with the road (i.e. press the clutch down and the noise subsides). Engage 2nd, 4th or 6th and the noise goes away immediately.

I'm thinking it's caused by a layshaft bearing or selector bearing, but without knowing the internal workings of the gearbox it's impossible to tell. Ideally I'd like to know how many layshafts there are, and which selectors engage which gear pairs.

The Audi garage want the car in for 3 days next week to investigate fully, but they've already found metal filings in the oil, which worries me. It also worries me the noise is slowly getting worse.

Does anyone have any ideas what this would be, or any diagrams on the gearbox? I just want to make sure I'm getting told the truth by the garage, and I'm worried that a "fix" might leave me with a gearbox likely to fail in future (it's now almost exactly a year old).

Any help/opinions much appreciated!

[KevTrem]

I suspect that your going to end up with a new gearbox. Its not worth Audi's time stripping yours down, ordering parts and rebuilding it for it to fail again. Luckily for you it still has 2 years warranty left so plenty time to assess if its going to go bad.

[lozzyho]

Thanks Kev, that's what I would have expected and I hope you're right, but they want the car in for 3 days to do some sort of "service action", which they tell me involves taking the gearbox out of the car. So I'm a bit worried that they're going to try to recondition it.

[Whippy53]

If it's borked, and it sounds like it is (first motion shaft?) Then it's a job for a specialist, more likely they'll simply swap it out.

[lozzyho]

The first motion shaft wouldn't explain the noise only being in certain gears, as far as I know.

But I'll be annoyed if my car is away for 3 days only for them to confirm it's knackered! I can tell them that now...

[lozzyho]

For the record, the car has now been fixed by replacing the entire gearbox with a new one.

The problem was traced to insufficient oil poured into the gearbox on the production line, since the level was low but no sign of any leaks. The lack of oil produced accelerated wear obviously, which presumably affected one lay shaft with gears 1, 3 and 5.

I have to say, Perth Audi have been fantastic from start to finish. I'm not used to garages getting it so right!

[KevTrem]

That's a good result on your part, hopefully that's the end of your issues. Well done Perth Audi sounds like they have got their customer service just right.

[lozzyho]

You're absolutely right Kev. Assuming my gearbox doesn't fall off in a few hundred miles they've been spot on!

Interestingly, the service manager did tell me they checked to see if the car was chipped before they did anything. If it was, Audi wouldn't cover it at all, which is harsh imo. Worth remembering though.