Hitachi 270 lc-5 Swing Bearing Leak?

My 270 is leaking mostly gear oil and grease from around the swing bearing.I have been adding about a half a litre to a litre of 80w90 oil to the swing motor daily.
It is making a mess and looks like s@#t to me.It only pushes the oil out in the cold weather(winter).Summer is fine...What is wrong with it?
Is there a breather plugged somewhere or what?

If Im getting it right, you are having problems with the swing gearbox seal. Oil is going to the swing grease and contaminating it. You should change the gearbox seal and check the grease as it would´ve become thinner and contaminated by oil. If it is also pushing oil out by the dipstick, then the swing motor seal is also damaged.

Juan

Good day Roadrunner
A common cause for this issue is that the lower bearing in the slew transmission has past its best, the root cause often is that excessive axial play in the slewing ring. We suggest it would be wise to check it out since any repair - replacement of the transmission would be short lived. Sorry not so good news.
Kind regards
Uffex

I had the same problem on my EX400-3. The seal for my machine was about $100.00 if I remember correctly from the dealer. They are easy to change once you get the swing motor and gear box lifted out.

My seal failed due to water build up inside the turntable which turned to ice in the winter and damaged the seal when the machine was run. There is a notch cut in the gusset between the two arms where the boom pins on the upper frame that is intended to allow water to drain away, but over time will become plugged with dirt and grease if not regularly cleaned. The water build up will eventually leaks down inside the turntable. I now make a habit of removing the inspection cover on the underside of the turntable in the fall of the year to drain any water that might of seeped in.

I am wondering why in the summer when temperatures are above zero that everything is fine with the swing motor gear oil.As i do not have to add any just in the cold.
Could the seals be getting "hard" and with the cold becomes to hard and the oil goes past the seal?
I should have checked for water build up in the turntable.
I am running the machine the way it is so i shouldn't hurt anything as long as the swing motor is full of oil right?And grease the swing bearing?

Not totally right. As long as the swing gearbox is full of oil you would not hurt anything, but it will start leaking more and more untill it becomes a big problem. The other problem is that grease in the pinion is getting thinner and mixed with oil, wich will decrease the "stay in its place" grease property. Remember the oil is going to the swing pinion, not the swing bearing. You should check that comparment and drain oil out from the grease, and check the grease. I am experiencing the same problem right now with a Komatsu PC-450. Just waiting for a new machine the company bought ( )to start fixing it.

Thanks ejuan
I will check the compartment for excess oil.So you think the ball bearings will not be affected by the oil?As long as there is enough grease in the bearing races?
The manual says to grease the swing bearing every 500hr but have you ever heard of over greasing it and pushing the seal out?Just wondering.

I will check the swing bearing play with a gauge soon to see where it is at for tolerance.
Sure hope it is ok!

uffex said:

Good day Roadrunner
A common cause for this issue is that the lower bearing in the slew transmission has past its best, the root cause often is that excessive axial play in the slewing ring. We suggest it would be wise to check it out since any repair - replacement of the transmission would be short lived. Sorry not so good news.
Kind regards
Uffex

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roadrunner said:

Thanks ejuan
I will check the compartment for excess oil.So you think the ball bearings will not be affected by the oil?As long as there is enough grease in the bearing races?
The manual says to grease the swing bearing every 500hr but have you ever heard of over greasing it and pushing the seal out?Just wondering.

Click to expand...

It will surely afect it, but will afect the most on the pinion grease, because it will leak just above it. About overgreasing it is totally true, ovregreasing will push the seal out. I grease all my excavators every 250h on the swing bearing. Just remember to move the swing 90º every time you pump grease, so that it can be distribuited evenly among the bearing. Tomorrow we will taking out oil from the grease compartment, maybe I can take some pics. The thing is you have to remember there are two different grease comparments. The swing bearing, and the swing pinion.

Juan

Juan the one grease inspection cover i have put grease in is the one by the toolbox and boom cylinder pins. Is the second inspection plate under neath the excavator/skid plate?
My manual doesnt show the location of the second one.
Please send some pics if you get a chance.
Good luck with your project!

It is a fairly common repair on these machines.Lift out the swing reducer and re and re the seal.Should take about 4-5 hrs with the right tools.You can drain the pinion case by removing a little plate in by the underside of the rotary manifold.and add grease more grease to the pinion by another little plate in the tool box .

joeblow said:

It is a fairly common repair on these machines.Lift out the swing reducer and re and re the seal.Should take about 4-5 hrs with the right tools.You can drain the pinion case by removing a little plate in by the underside of the rotary manifold.and add grease more grease to the pinion by another little plate in the tool box .

Click to expand...

Thanks I will do that and keep the grease packed in there till I get time to change the seal.