Yanmar 336 lift arms

[Vanar]

My lift arms are stuck in up position, any ideas

 

[J_J]

Check the descent knob under the seat.

Turn left to open the circuit and set the descent rate of drop , and turn right to lock the 3pt for transport.

You may have to remove the rate drop assembly to clean.

 

[Vanar]

Thanks J.J. I have removed the decent knob and piston, and still the arms are stuck in the up position, the tractor sat for a long time outside with the arms down, they came up ok, but now they seem to be stuck solid.

Check the descent knob under the seat.

Turn left to open the circuit and set the descent rate of drop , and turn right to lock the 3pt for transport.

You may have to remove the rate drop assembly to clean.

 

[Car Doc]

Well they are gravity operated down so I wonder if (or maybe you did already?) just add weight and see if they start moving may be rusted up in one of the pivots etc? Welcome to the group btw! :thumbsup:

 

[Vanar]

Thanks Car Doc, yes i put my Kubota loader bucket on the arms and they did not budge, am going to pull hyd pack of the right side, where the control handle fits, will see if this helps.

 

[J_J]

Try putting the 3pt lever down, remove all parts associated with the descent valve and sort of jerk on the lift arms.

There might be a rust plug in the orifice, so do not stand in front of the hole.

Try more weight if necessary, as the only thing keeping the 3pt cyl extended is hyd fluid, and to descend, the hyd fluid must have somewhere to go, and that is usually through the descend orifice and the down position of the valve.

 

[Leejohn]

Your 3pt piston rod could maybe locked at TDC or at BDC. It could of maybe flipped over on the wrong side of the rock shaft. Try give a good jerk up then down and if's it at TDC it just might go over. Now I'm not sure and how the rod is hooked at the base.

 

[Car Doc]

Do you have the auto draft control? Have a look at these pics and see if your controls look the same. There may be a couple ways they could be positioned that might cause the 3pt to not drop.

The little lever in pic 2 by the pipe plug is the speed setting. I can only imagine if it was set completely off it might cause it but I have never intentionally messed mine up to the point of inoperabillity going down anyway fwtw.

Otherwise I agree with the rest there could be something in the valving or possibly a mechanical issue with the rock shaft piston etc internally.

 

[Vanar]

Thanks Car Doc, just finished pulling power pack off trans case, that sucker is heavy, piston seems to be stuck, will get some pictures and hopefully will tear it apart on the weekend.

 

[Car Doc]

Welcome! Looking forward to the tear down and repair report there are a bunch of 336's on here and its sisters mine included.