Freaky gear changes

Hi, I've just bought this car as some of you know and I'm trying to make sure everything is perfect which is why I'm asking so many questions. When I put it in gear after a 5 mile drive on a hot day, the gears feel like they 'Spin' when I put it in, especially in third gear. 5th and 6th seem occasionally crunchy too. I've got Warranty until October on this car and I've spoken to Renault and they said they will replace the gearbox if it persists. Should I push for this?
 
defo..get it replaced...it wont hurt ur car and u dont have to worry about it..that would be my priority if still under warranty...
 
defo..get it replaced...it wont hurt ur car and u dont have to worry about it..that would be my priority if still under warranty...

Heading down Friday. Will complain like shyte about it and make them sort it for me.
 
id do the same..u might do a few thousand miles on it but it will eventually go anyway so why wait till ur warranty has expired..:bash:
 
From what I've read it crunching means it needs replacing most of the time. Whilst its still under warranty get it done or its going to cost you a lot of money later down the line.
 
if working correctly a gearbox SHOULD NEVER "CRUNCH" when changing gear.... get em to sort it promto!