Keblco SK60 swing motor

[Greg in KY]

1998
Kobelco SK60
2400 hrs(and all indications are that these are true hours)

The swing motor dipstick has about a 1/2" checkered tip on it-I assume the top of the checkered is full. There are no other markings in the dipstick.
The oil level was about 1" over the checkered. It was this way when I bought it.

I changed the oil in the swing motor reduction unit.

I drained the oil and let it drip a couple of hours. It did have a little bit of oil "clumping" and thickening but about what I would expect for 12 year old oil. No visible metal pieces. I was a little blacker than i would expect.

Only about 3 quarts of old oil drained out. Then I ran 1 quart of new oil through it to try to flush it a little. It drained out the quart I put in.

Then I put the drain plug back in and put in 3 quarts. I checked the dipstick and it was about 1" over the checkered.


BUT-The book says it holds 1.1 gallon.

Now the questions-
1) Is there a quart + of sludge in the motor?
2) Do I need to flush the motor with something?
3) Do I need to get it hot before changing the oil? ( I did run it about 1/2 hour then spun it around both ways about 10 times before changing)
4) Will running it with overfull -from what I assume is full on the dipstick -hurt it?

Thanks, Greg

 

[cps]

Id flush it with lighter oil, even diesel, but dont leave that in there to long! Dont think there should be 1.1 gal in there seems abit much! then try about 2 quarts in there she how this goes!

 

[finaldrive]

Now the questions-
1) Is there a quart + of sludge in the motor?
In the swing gearbox there should not be any sludge. Just gear oil.
The motor portion is powered by hydraulic oil.
Sludge would need to be looked at as a contaminent.
On this machine the swing gearbox has shown to be a problem area. A common practice on any type of gearbox, as a quick fix/band aid, is to put grease into it. Could the sludge be grease mixed with gear oil?

2) Do I need to flush the motor with something?
The motor, no. Check the hydraulic tank return filter and suction strainer if you suspect motor problems.

3) Do I need to get it hot before changing the oil? ( I did run it about 1/2 hour then spun it around both ways about 10 times before changing)
Yes

4) Will running it with overfull -from what I assume is full on the dipstick -hurt it?
The dipstick on the swing motor and gearbox assembly is for the gearbox oil level.
Yes it can hurt it. In my experience an overfilled gearbox causes the shaft seal for the gearbox to fail premature and leak oil into the slewing grease bath. I'm sure a mechanic can tell you more precisely the pitfalls of an overfilled gearbox.

If you suspect there was grease in the gearbox, pull it out and put new bearings in it before it destroys itself.

 

[Greg in KY]

CPS, Final drive,

Thanks for the responses.

I hate to use a flush on something that I cannot be absolutely sure there will be no residue. Seems to me like it would deteriorate the oil after refilling.
-
1) I really don't suspect grease because the oil drained right out. There was a little clump on the drain plug -smaller than a pencil eraser and one or two smaller clumps. There was no metal shavings or anything like that. The equivalent of maybe 10 drops of water came out first- the plug had no rust on it
.
The viscosity was a little thicker than new SAE 30, but again it had been in there 12 years.

Unless there is a very suttle indication that I am not aware of - the swing motor seems to work perfectly.

Actually the whole machine seems to work perfectly.

I am just doing the recommended 2,000 hr maintenance on it.

2) I do not suspect motor problems.
I changed the hydraulic fluid and it was unbelievably clean. The return filter had "145 hrs" written on it. The suction strainer had maybe 5 really small pieces of metal in it. The bottom of the tank barely go a white towel dirty.

The manifold strainer did have some metal shaving and stuff on it but I suspect it was just from the flush when the machine was near new.

3) I believe I will try draining the oil to the full mark then change the oil again -at the end of the day after working it.

I appreciate your time and advice,

Greg

 

[MR. KOBELCO]

hi, greg
please see my other post.
SAE 30 as referenced in your operators manual is incorrect.
80W-90 gear oil is to be used.
generally you fill to half way point in hatch mark.
monitor the oil level each day during your circle check when walking up to check your engine oil level.
if the oil level drops, you're leaking out the bottom seal.
if it rises the hyd swing motor shaft seal is leaking putting hyd oil into the swing gearbox.

also, inspect the lower portion of the swing gear reduction, you may have a greasable bearing?

 

[MR. KOBELCO]

hi greg,
as far as confirming the actual hours on your unit.
if the display has a mechanical clocked meter.
remove display cover to reveal the hidden digit underneath the face plate.
or if a newer model a fault code can be created in the cpu and the computer hours retrieved for comparisons.

 

[Greg in KY]

Mr. Kobelco,

I will take advantage of your generosity on a trivial matter-

How do I correct the time on the clock that is displayed on the screen?

 

[MR. KOBELCO]

hi greg,
it will help if you provide your ser# as well as e-mail me a digital picture of the layout of inside your cab. include the monitor display.
with this i can e-mail back info requested.
tks
adam.

 

[Greg in KY]

Mr. Kobelco,

Just to double check-
The (track)travel motor also calls for SAE 30 in the book and on the lube sticker inside the door.

Does this also need 80w-90 gear oil?

I appreciate you,

Greg

 

[MR. KOBELCO]

yes that is correct.
80w-90 in the final drive gear reduction too