John Deere 3020 Hydraulic Chatter

[shuff3]

3020 Pressure Control Valve (priority valve)
Original came on machine R31624R
o Hydraulics extremely slow and weak
 10 sec or more to raise 3 point
 Remotes very slow
Spring in valve very weak
Installed R40559
o For 3010 s/n range -049,999
o Hydraulics at spec
o Extreme amount of chatter
 Spring in valve is very strong
Parts manual calls for a AR51732
o Subs are
 R40154
 AR40403
 AR40029
 RE13273

Does anyone have an idea what is causing the chatter?
Am I using the correct Priority Valve (Pressure control valve)

 

[DLTTrekkers]

If pressure drops shatter starts.
Test your hi-pressure .

 

[shuff3]

DLTTrekkers,

Thank you for your input. I will check it again at the priority valve. I see you are from S. Africa. After I retired from Komatsu I spent time in Zambia implementing Komatsu haul trucks, dozers, and shovels at FQM Kalumbila. I have a lot of friends in S.A. I hope you are keeping safe.