7800 and 7810 3 Point won't lower

jd40203020 · Mar 22, 2017

I have a 7800 and a 7810 that I cannot get the 3 point hitch to lower. Both were in the raised position when I got them and until now I never needed to use them. On both tractors when the engine is started none of the dash lights are on. As soon as I operate the hitch controls the 3 point light starts flashing on the dash and will not stop until the key is turned off. Only thing I have tried is to push on the 3 point with a loader, which didn't do anything. Is this a electrical or hydraulic issue? Where do I start?

Tech 7 · Mar 22, 2017

They usually get seized. If you want to rule out a hydraulic issue, crack one of the fittings on the lift cylinders then apply the load. If it still won't go down you are into freeing it up. Any of the linkage that should move and won't will add up and cause seizure.
Does the rockshaft housing have grease fittings in it?. That was one fix. The other was changing out the seals on the cylinders. Moisture would get in behind the tin and rust causing the seal to clamp the cylinder rod enough to stop movement.

tim s · Mar 22, 2017

I have seen the rockshaft seize up on the big top shaft, to where I had to drive the shaft out, not an easy job and I had .060 turned off of it then re-install adding grease fittings, the early ones did not have fittings.

jd40203020 · Mar 25, 2017

Thank you! I will check it out soon and see if I can get one to move.

7800 and 7810 3 Point won't lower

jd40203020

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Tech 7

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tim s

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jd40203020

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