Just been giving it some, was doing some speed in fifth and all of a sudden I lost all the gears except fourth even reverse has gone.
1,2+ 3 were whining before and the car rattled with the clutch up.
Have i blown the box??

 

What car?

 

2wd cosworth

 

4th gear is direct drive. So the power is going through the input shaft and to the output shaft.

Your box is blown. Something has literally broken or fallen off internally.

 

Not good then ?

 

sounds like the gear on the back of the input shaft, as that turns the other gears, 4th as said is direct so dosnt use the "drop gear"

would be my guess, but only a guess !

 

Wud that b a full rebuild?
Think I'm gona cry!