I have an STi10 and when I take my foot off the throttle under load I get a clunk from under the car. Is this normal or Propshaft or Diff ? Do I need to take any action yet? Thanks Peter

 

Jack the car up and see if the prop shaft has any play in it on the join as the bearings maybe on there way out.

I also wouldn't leave it to long or put it on boost as the last person i knew had this problem came on boost and when it snapped off from the bearing joint part and then the prop went through the gearbox.

 

Wow ! thanks

 

Also check your driveshaft nuts. Easy to do, just pop off the centre caps in your wheels and look to see if the staking on the big (32m) nut is in the groove on the shaft.