JD 3005 3 pt hitch "bounces" every few minutes

[northernexposure]

My Deere 3005 3 pt hitch bounces every few minutes when I have it raised with the box blade on it. Its a Woods 5' box blade. The tractor only has 120 hours on it. Can it be that the box blade is too heavy, or is there an adjustment that needs to be done? It seems fine with lighter implements.

 

[pmsmechanic]

My 4410 did the same thing. On the left side rockshaft arm there is a short linkage from the rockshaft arm going down to a shaft which goes into the three point hitch housing. On the linkage there is a short threaded rod that has two nuts on it that are on each side of a swivel. Loosen one nut and either lengthen or shorten that rod. If the three point hitch quits surging then you know you've adjusted the right way. If the surging gets worse then go the opposite way. That should cure your problem. Make sure you keep track of the amount of turn on the nuts so that you can go back to where they were if this doesn't work on your tractor. I would try half a turn at a time untill the surging goes away.

 

[Tx Jim]

Incorrect adjustment of feedback rod could cause the rockshaft housing to break. Hunting (hiccuping) is normally caused from a leaking hyd component such as control or relief valve or leaking rockshaft piston seal. .

 

[RoyJackson]

If you have a service manual, you'll find the plug for the pressure relief valve under the operator's seat. That would be the first place I'd look since it's easy to get to. There's also a check valve in the system that might be cycling when it shouldn't be.
BTW, if you added shims to up the hydraulic pressure (a lot of 790/3005 owners have done so), remove those shims and see if that fixes the problem.


Added: I re-read the original post...the tractor has 120 hours on it, so it's probably still in warranty....if so, let the dealer handle any repairs.