Tascam 464 slamming rewind

[datewithtape]

Hello

I have a 464 in good condition

However it's started doing this funny thing where it will take a few seconds to stop when rewind or ffwd has finished.

Does anyone know how the machine knows when the reels are finished?

I have a spares 464 and tried swapping the sensor pcb, didn't change anything....

I've attached a video >>

Cheers

 

[datewithtape]

Tried cleaning reel tables and photo sensors, still does it.
I wonder if its a hardened idler wheel...