Komatsu PC60-60 Need Help - Swing Drive Motor Leaking Badly

big builder · Apr 25, 2020

Hello Everyone.

An emergency today. We spent a few day a couple of weeks ago servicing everything we could on the old PC as we had a very important couple of weeks for it.

Yesterday we saw a puddle under it where it was sitting right in the middle.

Checked today and the swing drive motor was out of straight 30. I filled it up and drove it a couple hundred feet to the shop and I could see the trail of fluid. Got under it to look and it was pouring out.

Very hard to see where it comes from in there.

Any ideas or can it only be the seal?

Has anyone heard of the seal leaking that bad? I mean it was a steady stream.

Next question as we are in the middle of something time sensitive and important. Has anyone done this? I am pretty good with the tools and we have a gantry crane in the shop. But I have never done this before.

Wondered if there is a manual for this machine out there?

Do people replace these with rebuilt ones or do we replace the seal ourselves?

Really hoping for some help.

THanks

big builder · Apr 25, 2020

Because we are in a tough spot here I had a thought so please dont judge....

Is there anyharm in running the machine with no oil in the swing gear if I am not swinging it? We are only using it to pickup equipment and load onto the barge.

Albeit heavy lifts for the machine I really am not swinging the house. If I do just a few inches here and there.

Any thoughts on this?

Thank you.

big builder · Apr 26, 2020

Any thoughts on whether we can use this machine if we dont swing it? Is the fluid in the swing drive only to lube the gears while it is working?

For the next few days we just need to use it to lift and place things on trailers and so just the arms and the tracks.

Any help is appreciated.

John C. · Apr 26, 2020

You need to provide more information. A serial number would help and maybe a photo of the serial number tag. I don't recall seeing a swing gear box on those small machines before. Most just have a high torque radial motor for the swing.

LACHAU · Apr 26, 2020

John C. said:
You need to provide more information. A serial number would help and maybe a photo of the serial number tag. I don't recall seeing a swing gear box on those small machines before. Most just have a high torque radial motor for the swing.

It has a planetary gear box, Sir.
Attached "pdf" file is how to disassembly.

Bls repair · Apr 26, 2020

Some here have pumped grease in in an emergency.

big builder · Apr 27, 2020

Hello, Thank you very much for the replies. I will post the serial number and tag today. I have not had any luck whatsoever connecting with anyone who can rebuild these. I will keep going at that this week.

I guess my immediate question is. If I am not rotating then I should be ok to use the machine for a few hours here and there loading things correct? My guy tells me I should be.

Another question is why would it fail so dramatically? Is that normal. I mean the fluid is pouring out. It will empty itself in less than 5 minutes.

Thanks again

John C. · Apr 27, 2020

The usual reason is because the oil has never been changed. All the wear materials that get generated end up in the bottom of the case and in that seal. In time that can also build up and end up in the pinion shaft support bearings cause a cascading failure. A drive like that is not hard to rebuild, getting it out of the machine might be the toughest part. Using the machine at this point is basically a game of chance. At this point it might just be the seal that needs replacing. Or the drive might already be broken so damage from any more turning just makes the repair that much more expensive. You will have to weigh the amount of money you are making on the job against the cost of repair or replacement of the drive. I doubt used will be much of an option but you might look before making a decision to use the machine more.

Bls repair · Apr 27, 2020

How long has it been since you checked oil befor this happened. How long it lasts depends on how much has damage has already been done.

LACHAU · Apr 27, 2020

big builder said:
Hello, Thank you very much for the replies. I will post the serial number and tag today. I have not had any luck whatsoever connecting with anyone who can rebuild these. I will keep going at that this week.

I guess my immediate question is. If I am not rotating then I should be ok to use the machine for a few hours here and there loading things correct? My guy tells me I should be.

Another question is why would it fail so dramatically? Is that normal. I mean the fluid is pouring out. It will empty itself in less than 5 minutes.

Thanks again

They's called SWING MACHINERY (actually it's planetary gear box) which is lubricating by ENGINE OIL.
It has a oil seal as picture below. You should check oil seal and also the shaft of it.

John C. · Apr 27, 2020

It's got a bolt on pinion gear retainer. That makes changing the seal easy!

big builder · Apr 27, 2020

I change everything regularly. So it shouldnt be a service issue. I use the machine sparingly.

I feel like we can change the seal once we get a little bit of time.

I did look up the tag this morning and its a pc60-6 serial number 41364.

I am in ontario and wondered if anyone had a recommendation on where to order parts from? We do not have any Komatsu dealers anywhere close by.

big builder · Apr 27, 2020

Thank you very much everyone for your help. It really is amazing. I see the seal online so I am sure I can order that. Should i be ordering any other parts at the same time to be sure once I have the swing
like the shaft and gear as well?

John C. · Apr 27, 2020

Sometimes the worn material wears a groove in the pinion shaft and if that is the case you will need a speedy sleeve installed to cover the worn area. You can get those at any bearing house. You won't know if you need it till you take it apart.

excavator · Apr 27, 2020

Just a few questions/ thoughts.I work on very few Komatsu excavators, mostly Deere/Hitachi. From reading the original post it would appear that you can see the swing drive gear from the bottom of the machine? If oil is pouring out that fast would it be wise to reseal the hydraulic motor also? It would almost seem like the swing drive is being pressured up for it to push the 30 weight out that fast.

big builder · Apr 28, 2020

I cant see exactly where it comes out. It is open right through the center but the swing drive is sort of offset. I believe the hydraulic motor sits on top of the planetary gearcase.

Yes it sure does come out. But I did notice the big puddle the first time when the machine was sitting after we used it for 20 minutes or so. But still we are not really doing any swinging. just lifting and loading onto our trailers.

Bls repair · Apr 28, 2020

Does the oil eventually stop leaking?

big builder · Jun 6, 2020

I am sorry for the long wait to reply. Was out of town for work. Yes its stops leaking...when all the oil is gone.

Of course I need the machine now....so I have it parked under my gantry and need to get this sorted out. I still dont have a factory service manual for this machine. Does anyone have a digital copy or know where to find one?

Thanks

big builder · Jun 10, 2020

I have found a online repair manual. From The Repair Manual.com. Worked really well.

big builder · Jun 22, 2020

hello, Update on my PC 60 issues. I have removed the gearcase and swing motor. I have never done this before so if anyone can explain to me now how to take apart to get at the seal to look I would appreciate it. I also encountered another issue. Take a look at the picture of what was below the gear can? It doesnt look good. Can anyone explain to me what happened there? There is some milky oil coming out of where the swing drive motor is attached. And yes the other picture which was right under the planetary set is completely full of that mess. Right to the top.

Komatsu PC60-60 Need Help - Swing Drive Motor Leaking Badly

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