I a rattle from aux belt led to me spotting the tensioner jumping around; I assumed it was the pulley bearing that was going. Ordered a tensioner, pulleys and crank damper; when I went to fit them, I found it was the bottom bush on the spring that had gone.
I could not be bothered to take the starter off to lock the flywheel, so I decided to leave the original 219k mile damper on. It looks fine, and is easily accessible if needs be in future. All of the pulley/idlers, all original, were smooth running. I did replace the pulley on the other end - power steering - recently, it had failed, so I thought it was best renew all of these.
To compress the tensioner, I cut down a large bolt (24mm AF) to fit 1/2" hole behind the pulley, and pulled the spanner back with a ratchet strap. It's a bit rough, done with an angle grinder, but it worked well.
Edited by imacleod, 16 June 2019 - 06:48 PM.