Check that the front balancer is also moving back and forth the same amount as the flywheel....if it is, the thrust face of the rear main bearing has collapsed and worn out....
If the balancer does no move back and forth the same amount as the flywheel, it can be two issues...most likely the flywheel is loose on the crankshaft.
Worse case if the flywheel is not loose, I have seen a broken crankshaft on the last web do exactly what is shown in the video.
I also suspect the pressure plate is a diaphragm type now, as it doesnt look like a Borg and Beck cover...(to these old eyes)....if it has been swapped over to diaphragm type...and the release bearing was not changed from Borg and Beck to diaphragm type....the clutch will not achieve release.
(The diaphragm type release bearings are taller than the Borg and Beck).
I have also seen a release bearing tightened up solid against the release fingers and burn right thru the fingers...but I suspect you have several issues...
Crank end play is way too excessive
Suspect release bearing is wrong height
Clutch Z bar may have bent arms
Clutch diaphragm spring has collapsed
Simplest way to accurately diagnose,
pull the transmission out and the clutch...
remove flywheel and check for broken crank flange...(grab it and wriggle it)...
if it moves at all...pull the engine....
Post pics once you get the trans out....
BTW...if this was a mechanics shop that replaced the clutch, does the work come with any warranty?
