Hi , I have a Ducato 2.8 JTD reg 2002 it has done 56k miles. After initial difficulty getting first gear I now get first gear ok but will not select 4th gear. Had the linkage checked and that is ok. Any Ideas??

The pivot point on the top of the gearbox can seize up. disconnect from the gearbox and see are all movements free.

Thanks, we checked that with the linkages. Looks like it may be gearbox.

the 5 speed gearbox has 3 selectors each clamped to 3 steel shafts that slide in the gearbox. 1st and 3rd are selected by one, 2nd and 4th by another and 5th and reverse by the third. It is slightly possible but highly unlikely that the clamping setscrew locking a selector to its selector shaft has come loose allowing that selector to become misplaced, so failing to completely engage those 2 gears. Even though Fiat assembly can be sloppy at times this seems an unlikely occurrence, unless the box has been stripped previously and carelessly reassembled. I had a Ducato 10 gearbox repaired once by a main agency and they replaced a selector shaft the wrong way round, thus defeating the interlock that stops you selecting 2 gears at once, which promptly happened. In such a case repair requires gearbox removal and a major stripdown.