Good evening. I have a John Deere 770a motor grader that has some serious blade drift on the right side. It started out With a little settling on the left side of the machine. After repacking the left cylinder and re adjusting linkages, I have found a bad spool valve for the left side “extend”. After calling a local tech to fix it(being the tool is only sold to John deer dealers), it still settles after replacing just the o rings and retaining rings. So I switched left side “extend”valve with right side “extend” valve, the drifting has switched to the right side. I can not find another spool valve to replace the bad one or find a whole new control valve assembly (all 6). I also can not find a hardware repair kit for the spool valve itself. Wondering if anyone could point me towards a dealer or salvage yard to buy individual spool valves or a whole new control valve. Thank you all in advance. And I look forward to using this thread.(first time). Thank you!
A similar thread HeavyEquipmentForums Has deere checked with there obsolete parts division? Vanderhaggs has some 770s parted out although they don't list the valve a phone call wouldn't hurt https://www.vanderhaags.com/equipme...rer=john-deere&model=770&modelcategoryid=1592 Larsons come to mind they have a lot of salvage equipment https://www.larsonimplements.com/constructionparts.htm Good luck and welcome to the forum
Thank you! I tried Vanderhags and all they had was a Ripper valve and the poppets were different dimensions. I will Try the other companies! Thanks a lot!
One option would be to get the valve body honed out and the rod rechromed and ground to size. Some years back we bought a new control valve for our 670A and it was something like $2000 for one piddly little valve cartridge. I think they are Cessna brand valves.
That’s kind of what I am leaning towards if I can’t find anything. I know the cartridge I was looking at buying was $500 for just 1 and there are 6 of them. The guys at RDO equipment gave me some shops that specialize in Those repairs so at least I have that as an option. Thank you! I appreciate it.