L455 loud hydraulics

[RedOpel]

Hi Everyone, First time posting here! I have an NH L455 with the Kubota diesel. The only issue it has is when maneuvering the skid steer the hydraulics are very loud. Its like a vibration chatter noise and I'm trying to find out what the heck is causing it. The hydraulics seem to be very strong and its never struggled to move or lift with full bucket of crushed gravel. Ive even stalled it out a time or two with the drive motors so I would'nt think its a pressure issue. The weird part is when its under full throttle the noise is gone and sounds completely normal under any kind of load. When its at idle and i move it it makes the vibration/metallic rattle. Any ideas what this could be? Thanks -David

 

[RedOpel]

Anyone have any thoughts on this?

 

[flyerdan]

Anyone have any thoughts on this?

The only thing I can think is that it's just the nature of the beast. They are designed to operate at a certain range where the most torque is available, and turning one requires brute force.
The metallic rattle at idle could be a loose shield plate or some component displaying harmonic resonance, like how a license plate might rattle at a certain rpm. I believe it was the Cessna 175 that had a geared engine/prop combo that was placarded prohibiting operation in certain rpm ranges as the harmonics could cause structural damage.
Check for something loose causing the rattle, and if everything else seems normal, observe how it turns on different surfaces. Clean, dry tarmac should offer the most traction, and require more force to turn on than loose dirt.