Automatic Gearbox
Automatic gear change very slow
Automatic gear changes are very slow with a delay at the expected point where you'd expect a gear change. It can feel like there's a lag between putting your foot on the accelerator and the gearbox shifting gear.
Auto kickdown not working on acceleration
When you put your foot down quickly on the accelerator the 'kickdown' function does not work and the car either stays in the current gear or goes into limp mode.
Automatic Gearbox sticking
When you put your foot on the accelerator, or take your foot off the pedal, the car doesn't change gear as you'd expect. It can seem as though the car is struggling to select the next gear.
Gearbox makes grinding sound
When changing gear the gearbox makes a loud grinding noise. This will be a more common occurrence on cars with manual gearboxes but can also happen with automatics. There can be various reasons for it but it always presents as a loud, unpleasant sound of mechanical scraping/grinding.
It's unusual that you'd need to replace the entire gearbox as more often than not the gearbox can be repaired, so you're more likely to have it rebuilt with replaced parts than to replace it entirely. The labour cost can be high when having a rebuild but it will still be cheaper than a replacement automatic gearbox.
A cheaper alternative to a brand new OEM replacement gearbox is a refurbished unit, these can be picked up from around £400 (for something like a Ford Focus). This is definitely the way to go if you're dealing with an older car that has no warranty. You'll often get a decent warranty from the supplier too so a bit of extra peace of mind.