Sorry but my experience is the damage is usually done.

But you have to make sure.

A ggod mechanic can listen to the end of the box and be sure.

But if it is so and your lucky and find well equiped garage it is possible to remove the offending bearing without removing the box!

But these days it's rare to even find a mechanic that will open up a gearbox.

I did have some success years ago "lessening" differential noise on a gear box using Molyslip gearbox addative.

Whether this will work?

That does sound like bearing vibration from what Peugeot call the second line bearing.

Us older people would say the layshaft.

The bearing sits at the end of the shaft directly under the 5th gear.

But get it checked by a pro mechanic first.

don't go borrowing grief!

Even draining and refilling with 2 litres and addative would be probably around £45+ from a garage .

An Ebay rebuilt unit is around £650 plus fitting.

Get it checked first.

Hi, I have successfully bodged my rattling gearstick on my 2015 Peugeot Partner by doing the following (its not 100% perfect but its 98% better):

Jack up the left side of the van on solid ground & support it on axle stands (- do not crawl under an unsupported van), crawl under the van & you will find the 2 gearchange cables on the passenger side of the gearbox tunnel. The problem is that there is some play in the cables where they are connected to the selectors on the transmission & this causes the 2 cables to vibrate/rub together causing the rattling noise. Note that the original cables have a stingy piece of rubber pipe on the to stop them rattling.

I took a bungee elasticated cord & wrapped it around the 2 gearchange cables & the antiroll bar several times, you want it to be tight enough so that the elastic absorbs the play in the cables, but not so tight that the cables are solid. Then take a cable tie & secure it through the convenient hole in the subframe & place it around the elastic bungee. This is to prevent the bungee from touching the exhaust pipe.

Then check the gearchange works ok & take the van for a drive, it took me 4 attempts to get the tension right, if it still vibrates then tighten/slacken the bungee as necessary. If the above doesn't work, the take some15mm diameter pipe lagging & put about 30cm on each cable & secure with cable ties & refit the bungee & use a cable tie to hold it away from the exhaust.

The silence in the cab is fantastic, I get the occasional mild rattle under hard acceleration, but you can live with it as it reduces under normal throttle.

I hope this works for you!