Yup. The Peugeot garage confirm it's a rear axle fault and a known issue with Peugeot. They're gonna change it under warranty. No questions asked. Just have to wait for parts now and until then keep the stereo cranked up to not hear the miserable squeeking.
The noise from the rear of my 2014 308 has been getting worse over the last few months. Took the car to the dealership back in January and they couldn't find anything. Went back on 29th June and insisted there was a problem. Sure enough - they diagnose rear axle problem. They said they would order parts. Today (2 weeks later) they booked the car in to get the work done. Found out it was the messy non-fix of fillers and grommits. At the same time I complained about rough engine running on first start-up of the day (subsequent starts were OK). Picked up the car this afternoon. They said their "fix" didn't work and the noise was still there. They would contact Peugeot UK to see what to do next. The starting issue was diagnosed as a timing chain problem. Again - no parts in stock and they would have to order it. So - after 3 visits to the dealership the car is the same as when I started. To say I am not impressed is a vast understatement. I have asked for all the paperwork for the visits as my warranty runs out in September. They didn't have it hand but promised to mail it to me.
I've just had mine replaced last week (2015 308 e-hdi 1.6). Main dealership knew immediately what it was as soon as the mechanic heard it. They ordered a new axle and it was delivered 8 days later!
Can't fault the service I've had, all done under warranty and included a courtesy car.
Hope everyone else with this problem gets theirs fixed as efficiently.
Had this on a 2015 1.6 Blue HDI thats now been handed back due to various other problems that appeared in the 3 months of owning.
The fix the dealer was going to do if I kept the car was to apply an adhesive that had been on back order for 6 months already. Got to say it didn't really sound like fixing the issue more just sticking the loose parts together.