Lightning gearchange

[davidwheeler]

Over the past few months, the VIIIth gear change has got more and more rapid.    First to second takes about 1/10 second, second to third is as fast as possible and third to top requires the merest hesitation.     I have drained the gearbox, flushed it with petrol and refilled with 80/90 grade oil but this has made no difference.   Driving is a bit difficult!  Any ideas, clutch maybe (though this is as sweet as ever).

[Mikenoangelo]

Something is slowing the gearbox input shaft, much as a clutch stop would if fitted. Suspect the thrust race on which the clutch actuating fork acts, or possibly the input bearing at the front of the gearbox or even the layshaft bearings. Is there  any new noise to be heard at tickover when out of gear or when pressing the clutch pedal?
Mike

[davidwheeler]

The clutch actuating fork works, via ballraces which are OK, on a disc which is attatched toa sleeve which fits round the input shaft.  I squirted some lube into it but this has made no difference.   The gearchange has always been different on the two cars no matter what gearbox was where (I have three to chose from) so part of it must be intrinsic to the engine.   I rebuilt the gearbox a few years ago but the problem has developed since.     No new noises and certainly there should be no increased friction from bearings (all new) or seals (modern lip seals).     It is a mystery!   I shall try to compare the deceleration times of the two engines.