Better still, drain the old oil completely and refill with fresh NEW oil of the correct specification.then.dispose of responsibly. Old gearbox oil loses it's properties after years of use leading to stiffness of gear selection; and grinding....if the clutch also needs attention. !

The first thing to try would be to top up the gear box with gear oil. It's a slightly different oil to egine oil but any car parts shop will sell it. Finding the top-up hole can sometimes be tricky so you might need a Haynes manual to find it and maybe an allen key to undo it. It is very common for gear boxes to run out of oil around the age of your car.

I would expect the above to solve the problem but, if it doesn't, you can phone round local scrap yards to see about replacing the gearbox. For some cars, this can be done for under £100.

i have a 1998 2.4 TD fiat marea and the gear change is getting stiff i am finding it difficult to change from 2 to 3 and also coming down the gears it is like the stick dose not want to go into the gears but when i get them in it runs like a treat dose anyone know what it could be

any help would be great