This happened to me on holiday this summer. Turned out to be a recognised fault with certain Fiats - the 5th gear is 'on the side' of the gearbox using oil scooped from the main gear box and it and/or the syncro wears. Parts - 5th gear and syncro cost me £470 from Fiat, fitted myself (average mechanic, no special tools, just confidence) in a day. If I do one again it will be a couple of hours. There was a link on a nother site from a guy who did this with photos (great help if you want to do it).
Fistral Beach (Fiat Ducato Swift Royale 1998)
December 2010
Sounds very much like the selector or selector ring has worn garage job I think.
Bob
September 2010
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