When to Replace Head Dampers

[T-ster]

How do you tell when you need to replace your head dampers? I have almost 2 gallons through my Align T-Rex 600 nitro and used the beginner, gray dampers that came with the kit. I'm able to rock the blades up and down slightly, so there is a certain amount of play. Is this normal or should they be replaced.

The black ones that also came with the kit state they are for 3D use, so won't be needing those buggers for quite awhile!

Comments?

[fllyer]

The only thing I can think of is replace them when the blades go out of track (were tracking perfectly) and there has been no crashes or hard landings.

At least that's my experience with my 450sa.