Gear change

[Peterdon]

I have a 1990 300TE-24, the gear change up seems a bit hesitant, as though it thinks about it for a second or two then decides to go for it. It feels as though it's not actually in drive for a moment. I've checked the fluid level and that's ok and nice and clean. Any pointers/ideas?

 

[Dieselman]

Try unplugging the vacuum line to the gearbox shift modulator. This should then give harsh but quick shifts.