Alfa Romeo Repair: Alfa 147 Gearbox, automatic transmission fluid, synthetic 75w

Question
Hi. I have an Alfa 147 and, when I went to drive it yesterday, the gearbox was very stiff and and I couldn't move gearstick around easily in neutral. It was a lot harder to fnd the gears as the stick did not move to its central position after being taken out of gear.

Not sure what the problem is as I am not very knowledgable about cars but want to learn more.

Many thanks for your help.

Answer
Lift the driving wheels off the ground. Drain the transmission and refill with automatic transmission fluid. Start the engine and run through the gears until the problem clears up. Drain the transmission and refill with synthetic 75w-90 GL-4 or higher.