So my focus has a whining noise above 15mph, it gets louder the faster you go. To fix this problem I've put on 4 new wheel bearings and a gearbox but the noise is still there. It's a 2009 ford focus zetec s 2.0tdci. I'm not sure what to try next. The noise doesn't change when clutch is pressed or depressed. Only way the noise changes is if you slow down the noise gets slower. Any advice would be greatly appreciated

If it's speed related rather RPM related, try swapping the tyres front and rear.  Some tyres make an awful noise!

Thanks for the reply, this is definitely some sort of bearing noise. I will change the wheels around just to eliminate that. The noise doesn't change with the rpm just with speed, that's why I thought it could have been the gearbox but no change in noise after changing gearbox 🙁

36 minutes ago, TomsFocus said:

If it's speed related rather RPM related, try swapping the tyres front and rear.  Some tyres make an awful noise!

That would be such a bummer that after replacing wheel bearings, and gearbox, it turned out to be tires! 😂

1 minute ago, StephenFord said:

That would be such a bummer that after replacing wheel bearings, and gearbox, it turned out to be tires! 😂

Indeed, but they've replaced the only bearings that move with road speed (gearbox/diff & wheel bearings).  

The only other thing that moves with road speed is driveshafts.  There's a slim chance that it could be the intermediate bearing on the OS shaft, but that's fairly unlikely.  CV joints don't tend to whine.  So that sort of just leaves the tyres...  

I've just swapped the tyres around and still makes the noise, I forgot to say I put a new support bearing on the driveshaft. It sounds like it's coming from the passenger side. Could it be a pilot bearing? I would have expected other symptoms with it if it was? No issues with the clutch or getting it into gear

6 hours ago, StephenFord said:

That would be such a bummer that after replacing wheel bearings, and gearbox, it turned out to be tires! 😂

At this point I would be happy for it to be the tyres 😂 I was convinced it was the gearbox

58 minutes ago, Dlews said:

Could it be a pilot bearing? I would have expected other symptoms with it if it was? No issues with the clutch or getting it into gear

I don't think there is a pilot bearing on these unless we're getting terminology crossed.

I think it's also known as the spigot bearing? It's the bearing that supports the input shaft for the gearbox, behind the fly wheel

9 hours ago, Dlews said:

I think it's also known as the spigot bearing? It's the bearing that supports the input shaft for the gearbox, behind the fly wheel

Yeah, we are thinking of the same thing then.  Not used on small FWD car engines.

Problem solved. I put another new wheel bearing on the front  passenger.. I only just replaced it about a month before the noise started so must have been a faulty bearing. There were no usual bearing symptoms though, no change in noise when turning steering wheel when driving, no play whatsoever when the wheel was off the ground. Can only think it never had enough grease. Anyways, at least the problem is solved and I have a spare gearbox 😂. Massive thanks for the replys, greatly appreciated 👍