3320 rockshaft quit

[Woody_NH]

I have 66 hours on the 3320 and this is my 1st problem with the machine.

I set out to do some driveway maintenance after a minor washout. I drove down the driveway get the landscape rake, hooked it up, raised the rockshaft, and drove back up the hill where I found that the rockshaft no longer would lift after a drop. No response at all to the control lever. I detached the rake and even with no load, no response at all.

I then shut off the machine and checked the hydraulic fluid level which was mid way between low and full. Then I restarted the machine and the rockshaft suddenly was working again. I finished the project with no other problem.

I called the dealer service manager today; his opinion is that a particle of something prevented a hydraulic valve from closing thus keeping the rockshaft in a bypass mode. The engine stop and restart may have purged the particle.

The service manager then asked if I changed hydraulic fluid/filter at 50 hours. My reply was that I followed the 3320 manual (page 46), engine oil/filter at 50 hours but not transmission fluid/filter. (BYW, there was a discussion of this here several months ago). He said that dealer policy is to change all hydraulic fluids at 50 hours but he will check on official JD policy and call me back.

Anyway, I ordered the transmission suction oil filter ($74) and 7 gal of HY-GARD fluid on the theory that I want to be sure that the system gets a clean restart even though the manual indicates that this is a 400 hour item.

Does anyone have any comments on the either the dealer's theory as to what the problem was or what service is required on 33xx machines at 50 Hours?
Thanks

 

[slaveToHorses]

I would think that changing the hydro fluid at 50 hours would be a good idea.

You didn't mention if your tractor has the power beyond option. If so then another possibility is the return hose is not completely seated. With the engine off, reset the hose connections.

 

[Woody_NH]

There is no power beyond installed. You may be right about the 50 hour change being a good idea, in my case I was following the manual for the 3320. I am still wondering about the dealer's theory as to why the rockshaft operation quit.

 

[Dex]

I have a 3720 and I had the same prolem on a job the other day. My BB would not lift. I went through the same check-offs you did. Checked the oil and then everthing worked fine after a restart. I will call my dealer and have them check it. I did not change the fluid at 50 hours. The tractor now has 160.