Tony,

Yes they all do that - it is due to the sudden shock load of the flywheel dumping it's energy into the drivetrain if you don't allow enough time for the engine revs to drop sufficiently between gears. I think the 'bang' or 'thud' actually comes from the rear diff.

Anyway, you should try to modify you driving style to be a bit more sympathetic to your transmission - allow a bit more time off the throttle as you change gears so that the engine revs are better matched to those needed in the next gear up. I don't think that rushing the change from 1st - 2nd really makes a huge difference to your acceleration, but it will eventually hurt the transmission (which isn't indestructuble in the Impreza).

I found it quite difficult to master fast, smooth changes (esp. 1st-2nd) - it does require you to modify your technique a bit. I'll try to describe what I've found to work for me: as you approach the gear change point, you want to roll-off the throttle smoothly so that the transmission is unloaded (neutral, not trailing throttle) by the time you depress the clutch. Change gears, and time re-engagement of the clutch so that the engine revs have fallen to those needed for the next gear up (i.e.
1000-1500 revs). Once the clutch is fully engaged (don't be tempted to slip it), smoothly reapply the throttle. When you get it right this is relatively quick, and has a very smooth almost elastic sensation to the deceleration/acceleration, and completely avoids putting any shock loads through the transmission. Start slowly, and then increase the speed as you master it.

I hope this helps..

Cheers,

Alex

As as a new owner I have experienced a drivetrain bang on changing gear from 1st to 2nd at speed.Is this a common problem known to others? Rapid gear changes bring out the fault and is not experienced on changing down the box in any gear.The car is new with no other fault in the transmission.

AlexM
Thanks for you reply.This confirms my suspicions.Your comments and helpful advice is much appreciated.