3320 3PH dropping??

[B8FISH]

On my 3320 with MX-5 (total of about 45 hours, 35 with the MX-5). I have noticed in the last week that the 3PH will not stay where I set it. As of now it acts like this: if I raise it all the way up, it will slowly start to drop--about an inch in 5-10 seconds. If I raise it to the mid-way point it starts to drop fairly quickly--about an inch a second until it hits the ground.

I have checked the following--rates seem pretty consistent no matter where the rockshaft flow control valve is set (it is a little slower but not much when closed), normal level of hydraulic fluid, doesn't seem to relate to RPM's. I can set it where I want it to be with the little height/depth adjustment "thingy" but that's about it.

Suggestions on what to look at/try next greatly appreciated.
B8fish

 

[B8FISH]

Well...dealer didn't have the answer either. They will be picking up on Thursday--I'll let you know the outcome.
Oh and BTW--I can "lock" the MX-5 in the up position with the drop rate valve completely closed.

 

[B8FISH]

Appears to have been no major mechanical flaw. Dealer removed rear tire and has "adjusted" the 3PH lever--seems like it may have loosened over time--hopefully this will not need to be done every 50 hours.

 

[nmu98]

So the lever was dropping ?????

 

[B8FISH]

Well--the lever would move as the 3PH dropped. I'm not sure if there is some sort of friction device on the lever that holds it in position or not. Wherever you put the lever (number setting) the 3PH would stay there. Not really feasible to mow and hold the lever at the setting you want the whole time. I'm just glad that it wasn't a major mechanical issue.

 

[GreatWhitehunter]

Fish, I recently posted about the same issue. It was the control valve itself not an adjustment or relief. I'd check it out to make sure your dealer isn't selling you a bill of goods. I really can't see the lever dropping and then the rockshaft recovering on it's own. What you described is exactly what mine was doing.

Matt T.

 

[B8FISH]

Matt--thanks, I'll look into that issue. Mine seems a little different in that both the 3PH and lever would move at the same time--and only down when I didn't want it to go down. I've had no problems with the adjustments you described.

 

[swines]

It may be as simple as a piece of dirt holding one of the valves open slightly. I had the same type of problem on a Ford 1720. On that tractor the fix was fairly simple as the top of the valve could be opened and the system flushed. Once I did that, it worked fine for the next 10 years.