Little Komatsu, Rumble In Swing

purnong · Jun 19, 2015

Howdy Guys
I have a 1.6 ton Komatsu mini and I've noticed there is a slight rumble feel when swinging
No real noise yet but you can definitely feel it when operating, Does anyone have an idea on what it might be and where to start looking
I'd like to find it and fix it before it turns into anything major
Thanks for any help

Garrie Denny · Jun 20, 2015

Have the turntable rings been greased lately ?

purnong · Jun 21, 2015

Garrie Denny said:
Have the turntable rings been greased lately ?

Hi Garrie
I have put grease in the three grease nipples on the side of the machine, I'm presuming they go to the turntable ring
I took the bottom cover off under the machine and it all looked pretty greasy, I wonder if it would be worth just putting a blob of grease on the ring in a few places
I suppose it couldn't hurt

Nige · Jun 21, 2015

What you need to do is to apply grease to the three grease nipples, then swing the machine say 15 degrees, grease again, etc. Repeat until you get back to where you started. How frequently do you grease it as a maintenance item..?

ih100 · Jun 21, 2015

They won't all be connected to the slew ring, one will do the head end of the boom offset cylinder(s).

John C. · Jun 21, 2015

Somewhere under all that sheet metal will be a cover that gives you access to the turntable ring gear. If the teeth are dry you will need two or three tubes of grease dumped in there at varying places as you turn the house.

purnong · Jun 22, 2015

Hey thanks guys
I went and did what Nige said and put five pumps in at various stages of the rotation and it does seem a bit smoother but the rumble is still there
Nige I only greased it about two hours ago and wasn't aware of the need to rotate
One thing though, I read on here somewhere about something you can over grease (Swing motor I think) would one of those side nipples go to that or can I just keep pumping to my hearts content
How do the two halves of the machine join, Is there a centre post or is it like two flat plates with a bearing in between, I might do some googling
Sorry for all the nooby questions, I haven't had this little machine long and apart from the pins and bushes having a fair bit of wear the rest of it seems really good and it's mainly for personal use so I'd like to get it as good as I can

purnong · Jun 22, 2015

purnong said:
Hey thanks guys

How do the two halves of the machine join, Is there a centre post or is it like two flat plates with a bearing in between, I might do some googling

Ok, Googling done and I think I found the answer, So the pics below would be fairly typical I suppose
I wouldn't like to think the rumbling is coming from that bearing

It looks expensive

John C. · Jun 22, 2015

The ring gear on your unit is on the inside of the ring and not the outside like in the big photo. Do you have up and down play in the bearing?

purnong · Jun 23, 2015

John C. said:
The ring gear on your unit is on the inside of the ring and not the outside like in the big photo. Do you have up and down play in the bearing?

Ok, thanks John
I haven't felt any up and down play at all while operating and I have pushed on the machine from the sides looking for play but there's nothing I can find
Appreciate the responses everyone, So should I just keep pumping the grease in and see what happens or can you overdo it?

caterpillarmech · Jun 23, 2015

I would have some body run it for you. Put the bucket on the ground and put downward pressure. If your bearing is out you will see the car body pull away from the track frame slightly. I had one with a rumble but mine had the bolts fall out of the bearing. I about fell over when I saw it. My machine would separate by an inch right in the center as all the mounting bolts had backed out.

purnong · Jun 23, 2015

caterpillarmech said:
I would have some body run it for you. Put the bucket on the ground and put downward pressure. If your bearing is out you will see the car body pull away from the track frame slightly. I had one with a rumble but mine had the bolts fall out of the bearing. I about fell over when I saw it. My machine would separate by an inch right in the center as all the mounting bolts had backed out.

Ouch, Ok I'll look at doing that on the weekend and see if anything moves where it shouldn't
Just out of interest what did you do to repair it, Was it as simple as doing the bolts up again?

Garrie Denny · Jun 25, 2015

There is nothing on an excavator that I know of which can be over greased(Except track adjuster). No greasing on a regular basis is a sure fire way of wrecking good equipment.

caterpillarmech · Jun 26, 2015

I had to split it and replace the bearing as the holes had ovaled. My loose bolts had actually got into the swing motor and ring gear. This is what had stopped the machine from swinging.

purnong · Jun 26, 2015

Garrie Denny said:
There is nothing on an excavator that I know of which can be over greased(Except track adjuster). No greasing on a regular basis is a sure fire way of wrecking good equipment.

Hi Garrie
I did a fair bit of reading on this site about it and apparently the swing bearing has a rubber seal that can blow out if it's over greased, Search I used below

https://www.google.com.au/search?q=...tor+site:www.heavyequipmentforums.com&start=0

I'm going to have a good look tomorrow and see what I can find, Grease gun in hand of course

purnong · Jun 26, 2015

caterpillarmech said:
I had to split it and replace the bearing as the holes had ovaled. My loose bolts had actually got into the swing motor and ring gear. This is what had stopped the machine from swinging.

Crikey, I'll have a good look tomorrow then for sure
I know there is a plate under the body that gets removed to see the swing gear so I'll see if I can check the bolts as well from there
This is all good info fella's and helping out big time, Thanks for the responses

purnong · Jun 27, 2015

Had a good look today and couldn't really detect any movement up and down, Had someone else use the boom to lift the machine while I looked under the body to see what was going on
The ring is well greased and the teeth look good and the only thing I could find wrong is a small oil leak but I can't find where it's coming from so I might just live with it
I could not see any of the bolts that hold the ring on but it is pretty tight under there, Do they usually bolt from underneath or the top?
I might have to drive it up on a couple of railway sleepers to give me a bit more height and look again, I ran out of time today
The rumble does seem to be a bit less so maybe the grease is working it's way in to where it needs to go with some luck

Little Komatsu, Rumble In Swing

purnong

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Garrie Denny

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purnong

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Nige

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ih100

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John C.

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purnong

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purnong

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John C.

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purnong

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caterpillarmech

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purnong

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Garrie Denny

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caterpillarmech

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purnong

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purnong

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purnong

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