Any of you wonderfully knowledgeable guys help with a problem?

Son has just shouted for help with his car ('96 primera 2.0 manual).

Suddenly the car won't go - it seems to select all gears perfectly, then when you let the clutch up there is just a slight dip in the revs, and all you get is an awful graunching noise (rather like the gear is 'not quite' selected?) it does that in all gears, the only difference is the speed of the graunching sounds is speed-related. Interestingly, the speedo shows you are moving!

Any thoughts and advice would be great.

broken gearbox! one of the shafts probably, rather than a gear

edit: shafts as in gearbox shafts (1st motion shaft/lay shaft? is that what they're called?)

[Edited on 21/10/11 by blakep82]

broken half shaft? That would make the revs dip a bit.

[Edited on 21/10/11 by JoelP]

I have just jacked it up - with it out of gear, turning one wheel, the other doesn't move. With it in gear, the other wheel turns the opposite way. - So, thanks joel, but both half shafts are in one piece.....

It sounds like gearbox or diff if it hasn't broken a shaft . If it was a clutch with the center plate boken you would get similar symptoms but without the speedo working. If you can get the car on a 4 post lift it may be easier to diagnose

Found the problem - broken outer CV RHS (so apologies to Joel - you were damn close!)
Thanks to Mel and Blake for your quick responses, too.

On some FWD gear boxes the sun gear is bonded on to differential and can come loose giving exactly those symptoms. Seen this with the entry level Peugeot/Citreon/Rover box.
Another possible is the outer CV joint splines have fretted and stripped the splines in the drive flange (ie wheel hub) --- used to be quite common on the 1800/2200 BMC/BL FWD cars at high mileages.

[Edited on 21/10/11 by britishtrident]

Ok, so finally bottomed this problem- it WAS the RHS outer CV - Almost exactly what British trident said - but it was the splines on the end of the driveshaft and the mating splines in the centre of the CV 'spider'.

I have now been left with a nasty leaking driveshaft/gearbox seal and the ABS light has come on.....?