Removing swing motor

[Gav88]

Hi all, I'm about to remove the swing motor from my late 80's, early 90's AX40U Airman excavator and was wondering if there is an easy way to do this, any tips would be greatly appreciated. Reason for removal is when slewing the machine, it jumps and grinds like there is something stuck in the gears. When slewing slowly the machine will at times get stuck and will need to slew the other way and then slew back quicker to get past the sticking point. I have separated the machine and checked the main gear and pinion but this was all found to be in good condition. I also pulled apart the main bearing and separated the bearing races and again found very little wear here. There was some very minor marks in the race and one or two balls had some very minor marks, but nothing that would suggest an issue. Also, would anyone have any suggestions on where I could get a hydraulic schematics for this machine. Thanks very much, Gavin.

 

[CRAFT]

Hello Gav88 ! …. and Welcome to HEF !!! ….

Are you absolutely sure that it is the Swing Motor ??? …. And NOT the Swing Bearing ??? ….Symptoms you are describing Sure Sound like the Main Bearing !!!

If you have to remove the Swing motor the best advise I can give is … Have at least a good mobile crane or A-frame stand to go over top of the Motor to have a lifting device to lift it high enough to clear the housing behind and be able to swing or roll the stand back, lower it down to the ground to be able to work on it …..

Other than that it's a matter of disconnecting all of the lines and capping them off …..Keep it clean !!!

 

[John C.]

I don't know about this particular brand but usually the swing reducer is in there pretty tight on dowels. Larger machines used jack screws to lift the swing machinery loose of the house and dowels. Maybe yours has them or not. Clean the base of the flange good before you start to lift it out. If you don't have jack bolt holes I would remove the swing motor and weld metal rings on the top of them for eye bolts. Screw them back into the machinery and put some strain up with your lifting device. I usually shake the rigging side to side pretty hard to loosen things up and the machinery clears.

Good Luck

 

[lantraxco]

Airman usually are pretty small machines, a crescent wrench and a two pound dead blow should do it. It may not even have any reduction, just straight motor to pinion. Of course it's probably in an impossible to reach spot to the right rear under the seat?

 

[Gav88]

Thanks Craft, I too thought the same until I pulled the bearing apart to find nothing wrong with it! I checked the main gear and pinion gear and also found no issues there. Given that there was nothing wrong with these items that is why I am now looking at the swing motor, I don't know what else it could be given the other components are ok. Im currently in the process in putting the two halves of the machine (top and bottom) back together and then moving onto the swing motor. I'm having some issues getting all of the holes to line up (undercarriage bolting to the top section) and I think it is due the way the pinion gear is meshing in with the main gear. If I disconnect the hoses on the swing motor will this allow the pinion gear to free spin so it will mesh in correctly or is there a break that will need to be removed? Thanks again for your help, Gavin.

 

[cutting edge]

I'm having some issues getting all of the holes to line up (undercarriage bolting to the top section) and I think it is due the way the pinion gear is meshing in with the main gear.

Is this not a red flag?

 

[John C.]

Take the swing motor out before you set the house back on the carbody and the bearing will line up easily.

 

[Gav88]

Thanks John C., that makes perfect sense

 

[Gav88]

Thanks cutting edge, I understand what a red flag is but what are you waving the flag at in my situation? Appreciate your response