Hi, my names John and I’m new to the ford scene. It’s only the second ford I've owned.

I've recently bought a P reg mk 6/7 Escort Si 1.8 16v Zetec.

About 2 weeks ago I noticed after going 80mph+ for a while then coming to lights and pulling off again, there was a horrible noise. A sort of grinding/ knocking noise. It stopped after I hit 40 - 50mph and only seemed to happen when I was going slowly. After half an hour or so I wouldn’t hear it again until I went fast again. It happened a few times then stopped for a week or so until tonight.

I was going down the M1 came off the slip road, waited for lights to change and set off again. As I did the noise happened again and it was really difficult to change out of 3rd gear, I had to really yank it out. I went down the slip road back onto the M1 and after about a 2 miles it made a clattering noise and rev'd out as if it wasn't in gear. So I took it out of gear and put it back in 5th and it did the same. Now I don’t have a 5th gear. It goes in as it should but just rev’s and won’t engage, just like it’s in neutral.

Does anyone have an idea what would have caused this?

Also what would be the best gear box to replace this one with, assuming it’s had it completely?
Do I have to fit a 'box from another 1.8 Si 16v Zetec or would I be better off fitting one from a different model? i.e. Mondeo, Sierra, Orion.
If I can fit one from a different model ford will it matter if I fit a 'box from a diesel, are they the same?
What about fitting one from a bigger engine?
Would fitting a ‘box from a bigger engine make it more economical?
What choices do I have?

I would appreciate any help you guys could give me.

Thank you

John