08 Cooper S Conv driveshaft or gearbox?

[MX-5 Lazza]

Mrs Lazza has a 2008 Cooper S Convertible (so supercharged engine) and it has developed a nasty knock. It's happens on coming on/off the power and is there pretty much all the time at low speed.

To me it sounds like a driveshaft but we took it to a local indipendent garage (not a mini specialist but good guys who I trust) and they said that while it did sound like a drive shaft, it could also be a problem in the gearbox. They said that there is a common problem with them, something to do with a pinion (I'm hearing this 3rd hand, my non technical Mrs took the car to them). Does this sound likely? I know the old 5 speed gearbox had quite a few problems but I'm not aware of common problems with the later 6 speed.

[DanGT]

The S box is normally quite good. CV joints would be higher up my list.

[MX-5 Lazza]

DanGT said:

The S box is normally quite good. CV joints would be higher up my list.

CV joint is exactly what it sounds like. My guess is that the garage have heard about the early 5-speed cheese gearbox and are tarring the 6-speed with the same brush but thought I should check with those more in the know.
Like I say, they are a decent garage and I trust them. As an example, they were looking at the car for about an hour and basically came to the conclusion that it was probably the driveshaft but with a warning that it could be the gearbox. They didn't charge anything for their time and suggested taking it to a dealer, or even better, an independent Mini specialist to find out for sure so they weren't fishing for work.

[ging84]

I would check the engine mount, the damper on these is prone to failure and can cause issues like you have described

[MX-5 Lazza]

I thought about engine mount but it definitely sounds like a rotational noise. I heard the car arriving home yesterday and it doesn't sound good

[Feirny]

Have you checked the wheel bearings? They're a hub setup and very prone to going, it's usually those that go and sound awful.

[MX-5 Lazza]

Not properly. I've pulled the wheel about to see if I could feel any slack in the bearing/bushes but couldn't feel anything. I'll try at the weekend with the wheel off the floor.

[CarsOrBikes]

Check the inboard cv hasn't come out (clip released) from the box

[MX-5 Lazza]

I should have trusted my ears. It was a knackered drive shaft. All fixed now.
The hub-nut on that side was not the original so I'm guessing it has had a knock on that corner at some time in its early life and a wheel hub/bearing was replaced and the driveshaft has finally given up following on from that.
The garage also blamed the missing brake disk retainer screw but I can't believe that had any effect as its only job really is to hold the disk on while the wheel is removed, it isn't there to stop the disk moving, the wheel clamped to it does that.