JD LX280 gator blades

[professor]

I bought Oregon brand gator blades from my JD dealer. When I installed them there was vibration and a blade came off and I put the one back on and tightened them again (air wrench) and the same thing happened. I discovered the Oregon brand has a 13/16" center hole and the JD brand has a 53/64" hole. Could this difference cause them to work loose?

 

[beenthere]

I wouldn't put them back on until finding out the problem. But don't think the 1/64" difference would be the problem. I suspect the blade that vibrated and came loose was not seated, from your description.