Good Day I got an older 490 John Deer excavator with a forestry package and a fabtek timber harvester head. The issue I got is when bringing the boom in or lifting it up the stick becomes jerky. Other then that the machine works great. Just wondering if anyone had a quick fix for this? Thanks for all your help.
Any letter designation with that 490 model ?
shes the early one no letters just a 490.
That Deere 490 straight is all mechanical control linkage up to the control valve spools and also cams and roller shafts connected to the pressure controller valves mounted at the side of the left and right control valve banks. A control valve spool in each bank is stroked when using the arm in/out and also with boom raise functions. Check all the control linkages/pins for excess play on the arm and boom function controls. The arm function control linkage also has a hydraulic “assist valve “,make sure it is operational.
Thank you I will check.
Yeah, that kind of jerky movement usually points to a hydraulic flow problem. Could be a sticky valve, air in the system, or a worn cylinder, pretty common on older Deeres that have seen forestry work. Hopefully it’s a simple fix and not a major teardown.
Thank you.