High noise levels

[WinterHill]

Hi All

I have a 12 foot by 6.5 foot walk in freezer room. It used to be mounted on the back of a vehicle. It has a brand new single phase motor in the outdoor unit and has been converted from 3 phase. It is cooling nicely but is so noisy that I'm concerned that somebody may complain about the noise! It sounds like the entire box is resonating and 'drumming'.
Should it be this noisy?
The box is sat on 2 wooden runners. Would it be less noisy if sat straight on the ground? Has anybody come across this problem before?
I'm an electrical engineer by trade. I'm thinking of running it briefly with the belt removed to establish if it's the outdoor or indoor unit that is making all the noise.
Any suggestions?
Regards

[Brian_UK]

It might be worth while checking all of the anti-vibration mountings to ensure that they are still working.

Mind you, listening to some transport units I am surprised at the noise they generate.