John Deere 490 Fabtek Swing Box Seal Gone Maybe Fill With Grease??

[c greenham]

Good Day

Yesterday I did a grease job on the turn table and swing bearing on the 490.  I removed the plate between the boom as per manual and was going to put 1lb of grease on the gear.  There was what looked to be gear oil in there so I didn't add any grease.  I then pumped 10 shots of grease in the fitting and rotated the cab 180 dergrees as per the manual and resumed greasing.

This morning I used the machine for about an hour and it started to leak what it looks like gear oil from the turntable area.  

I have a question

1) Is there sussposed to be gear oil or grease in the turntable?

Maybe I should not have greased it at all

Thanks for your help.



 

 

 

[Mapleman]

For what it's worth, my CAT 312 excavator started doing the same thing this summer.  I'm suspecting that there's a bad seal on the swing motor that's letting oil get down into the turntable, mixing with the grease and leaking out some sludgy stuff.  I'm also losing oil from the swing motor, which supports that idea.  I'm hoping to get the swing motor pulled out before it gets too cold to see what's going on.

[Wlmedley]

Better check oil level in swing drive gear box.Seal must be leaking.That's the only way gear oil could get in that area.

[Southside]

Been there, done that on mine. It's no where near as fun as it looks. 

[Wlmedley]

I've did a lot of them on Komatsu excavators over the years.It's a pretty big job.Sometimes gear box will be way over full.In that case seal is out of swing motor also.

[teakwood]

Definitely swing gear box seal, as mentioned above assure that is enough oil in the gearbox or it will become expensive 

[c greenham]

What can I see if I take this cover off the bottom of the machine will all the gear oil come out?
 

[Skeans1]

@c greenham 
That should be for your rotary manifold. Have you checked to make sure it's gear lube not hydraulic oil?

[c greenham]

It don't seem to be hydraulic and the swing box isn't low so not sure were it's coming from.  Like to get it out to see if it will come back. 

[barbender]

That probably means it is hydraulic then. When the hydraulic oil mixes with the gear box oil, it ends up smelling like 80/90 too 

[Wlmedley]

I've worked on Cats and Komatsu and think John Deere would be similar.After taking round belly pan off you should be able to see sheet metal pan which holds grease .There should be a small plate with two or three bolts holding it which comes off and will drain pan.Make sure swing gear box is not over full.Sometimes swing motor seal will fail which overfills gear box and blows seal in it.Also if to much grease is put in pan it will be forced out to the outside of swing bearing while swinging.

[Southside]

I have had that cover off and can't recall what it did for me but it wasn't the solution to the swing motor or the gear box.  All that had to come out of the top, and a number of hoses are in the way along with the rotary valve.  It's been a few years since I did that repair, sorry for not being more help.  

[Wlmedley]

Motor and gear box comes out the top but with bottom cover off you should be able to go up beside rotary manifold and get small plate off grease pan.Plate will look similar to the one on top he took off.If oil has mixed with grease all old grease will need to come out this hole after repairs are made and new grease put back in from the top.

[c greenham]

I pulled the drain plug on the swing transmission this evening, no oil.  I put in another 3 litres it ran on through.  I guess the seal is gone.

Going to take the swing box out, any tips on the process.  

[c greenham]

Pulled the plate of the bottom of the machine took out 20 litres of fluid mostly water  
 

 

[barbender]

Ewww

[Wlmedley]

That's the plate I was talking about.Looks just like a Komatsu.You will have to remove swing motor first.Not to hard,probably bolts to swing gear box with two bolts.Will need to block off hydraulic lines to keep from loosing hydraulic oil.Don't know your machine that well but may need to remove some hydraulic piping so gearbox will clear coming out.Gearbox will probably have to be torn completely down to change seal.Seal usually doesn't go out unless something is wrong with gearbox anyway.While gearbox is out you will need to wash all old grease out of pan and put in clean grease.Gearbox should be a tight fit in frame and will be held with several large bolts.Definitely will need a good impact wrench to remove.Hope this helps.Not a fun job.I've done several.

[Wlmedley]

Also water should not have gotten in pan.The  little cover on top should have had a gasket on it.The gearbox is usually sealed where it mounts with silicone.If both areas look like they were sealed up look for frame cracks in gearbox area.If I lived close I would give you a hand.Kind of miss working on equipment but not to much  :laugh:

[teakwood]

That's the plate I was talking about.Looks just like a Komatsu.You will have to remove swing motor first.Not to hard,probably bolts to swing gear box with two bolts.Will need to block off hydraulic lines to keep from loosing hydraulic oil.Don't know your machine that well but may need to remove some hydraulic piping so gearbox will clear coming out.Gearbox will probably have to be torn completely down to change seal.Seal usually doesn't go out unless something is wrong with gearbox anyway.While gearbox is out you will need to wash all old grease out of pan and put in clean grease.Gearbox should be a tight fit in frame and will be held with several large bolts.Definitely will need a good impact wrench to remove.Hope this helps.Not a fun job.I've done several.

Looks exactly like the Volvo also.
mine had a rubber hat around the centre turn joint, where all the hose go down to the track motors, and this rubber had a crack and filled up all the grease with water

[c greenham]

I'm getting allot of advice to just fill the swing box with grease.  It appears if the swing gear is taken out it will probably be other issues.

  If it's filled with grease may last for who knows how long.   What do u think??

It appears that is been used for sometime with nothing so grease can only help, at least that's what thinking.  

Any one every try this before?

[Southside]

I have done that with other applications and it worked fine. It's definitely not a high speed issue. 

[Wlmedley]

Inside gearbox probably has one or two sets of planetarys.Top one spins pretty fast.If bearing goes out on pinion shaft you risk damage to big ring gear which is part of circle bearing. I'm not much of a risk taker. I would guess something is already going bad in gear box which caused seal to fail.Your call.

[c greenham]

I mixed 80w 90 and lithium grease together, just enough to to get it to run but not flow,  Thick molasses.

I pumped in two liters into the swing gear, lets see what happens.

Got to be better then no oil, I will let you all know if it runs through, going to put the inspection camera in this evening to check to see if it went through the seal.

[Wlmedley]

Is this a high hour machine?I don't know much about values of used machines or what it would cost to replace it. I know parts are expensive.Maybe you could find a used gearbox off a machine someone is parting out.If it was a final drive would you put grease in it? Swing gear box is basically the same thing.Only thing is if final drive fails only thing damaged is final drive.Swing box failure could damage circle gear which means turntable bearing replacement.Just trying to help,something to think about.

[c greenham]

Yesterday I pulled out what looked like stainless steel metal out of the turn table with a magnet, it was all in pieces and torn up.  I'm thinking the lower seal came out completely and was squished in the ring gear.

Is this possible? Is this seal lined with stainless steel?

Thanks for all your help.