I dont know if this has been posted before, however, if it has, I crave your forgiveness. The mechanic at my local garage was a fitter for Fiat. He has told me that removing the gearbox dipstick, measuring 20mm from where the stick comes out of its holder sleeve, and then marking with a junior hacksaw, will increase the gearbox oil capacity by some 60 ml once topped up to this level. No detriment to seals, says he. Apparently, this mod was issued to all FIAT agencies some time ago, and will reduce the occurrences of 5th gear failure, by ensuring a better oil splash effect. Not sure about other Fiat gearboxes with the same problem, he couldn't remember if it covered them all, however, he did say that they all pretty much conform to the 2.5 box.