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Oil leaking from the gear box- Monarch Ser.60

MichaelP

Titanium
Joined
Dec 7, 2008
Location
IL/WI border
Oil leaking from the gearbox- Monarch Ser.60

I'm losing gearbox oil too fast. I found it's leaking along the upper edge of the left pedestal side door down to the floor. I could see no other spots.

I opened the left cover of the gearbox to expose the end gears, oil sump and the pump. I examined all visible point of lubrication when the pump was on, but couldn't see any unusual splashing of oil that could end up outside of the sump.

Then I removed the pump and the sump and found oil accumulation in the space under the gearbox floor (between the floor and the top of the pedestal). I suspected that the junction between the sump and the body could be the area that might allow oil to leak, so I used a liquid gasket material on the interface. It didn't help. If I remember correctly, I checked if the oil would leak when the lathe was not powered, and it did.

I spoke to Steve from Monarch, and he said that he never heard of such problem. Since I never removed the gearbox, I don't know if it has anything on the floor that can leak. Steve could think of only two potential places there: the screwed down bottom plate and seals of the shaft that holds the knob on the lower front of the gearbox. But he considered it not very likely. As far as I can see, checking them would require removal of the gearbox that I've never done before.

Do you have any idea of where such leak can come from and how hard it would be to remove the gearbox and inspect those two areas? I browsed through Harry's threads, but couldn't find any description of gearbox removal.

Any other ways you'd approach this problem? I still hope that fixing the problem won't require any monumental job. But just adding oil doesn't seem to be reasonable any longer. I'd, probably, need to do it twice a month, roughly.

As far as I know removing the front cover that has the feed table and dial will not allow a good visualization and access to the gearbox floor.

Thank you.

Mike
 
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Monarch Ser.60

I'm losing gearbox oil too fast. I found it's leaking along the upper edge of the left pedestal side door down to the floor. I could see no other spots.

I opened the left cover of the gearbox to expose the end gears, oil sump and the pump. I examined all visible point of lubrication when the pump was on, but couldn't see any unusual splashing of oil that could end up outside of the sump.

Then I removed the pump and the sump and found oil accumulation in the space under the gearbox floor (between the floor and the top of the pedestal). I suspected that the junction between the sump and the body could be the area that might allow oil to leak, so I used a liquid gasket material on the interface. It didn't help. If I remember correctly, I checked if the oil would leak when the lathe was not powered, and it did.

I spoke to Steve from Monarch, and he said that he never heard of such problem. Since I never removed the gearbox, I don't know if it has anything on the floor that can leak. Steve could think of only two potential places there: the screwed down bottom plate and seals of the shaft that holds the knob on the lower front of the gearbox. But he considered it not very likely. As far as I can see, checking them would require removal of the gearbox that I've never done before.

Do you have any idea of where such leak can come from and how hard it would be to remove the gearbox and inspect those two areas? I browsed through Harry's threads, but couldn't find any description of gearbox removal.

Any other ways you'd approach this problem? I still hope that fixing the problem won't require any monumental job. But just adding oil doesn't seem to be reasonable any longer. I'd, probably, need to do it twice a month, roughly.

As far as I know removing the front cover that has the feed table and dial will not allow a good visualization and access to the gearbox floor.

Thank you.

Mike
there's a little hole in the The shaft side of the gearbox do you have any oil coming out of that hole? I've been through all this with mine got the leaks fixed there was a bunch.I do have pic on some of it but I'm not very good on posting that stuff before you pull the gearbox make sure there's some blind bolts that hold it on.
 
there's a little hole in the The shaft side of the gearbox do you have any oil coming out of that hole? I've been through all this with mine got the leaks fixed there was a bunch.I do have pic on some of it but I'm not very good on posting that stuff before you pull the gearbox make sure there's some blind bolts that hold it on.
The hole you mention is plugged, but this is one area I continue monitoring.
I'll send you my e-mail address by PM (Private Message), so if you don't mind, you can send me the pictures and any additional info or suggestions you may have.

Thank you

Mike
 
Do you have any idea of where such leak can come from...

IF... you drain it... can you get a "wand" of thin tubing coupled to an air-gun into enough places to follow around the seams, shafts, & such? Sound and/or a ration of oil being blown out might find the pathway fairly fast. If Monarch hasn't seen this? You MAY even have casting damage on the inside - busted-off edge or such?
 
The access to the box interior is extremely limited. Besides, I won't be able to see the result of the air blowing because there is no visual access there. Any areas open for visualization are pretty much examined already (although I'm still watching some of them).

Based on the oil seeping rate, the leakage area is not large. Something like a faulty packing or gasket or seepage around bottom plate bolts. So even if I use a clinical endoscope for the lathe colonoscopy, it may be hard or impossible to pinpoint (unless it's some kind of a bottom fracture, which is somewhat less likely, although possible).

Of course, in theory, I could use light oil with a marker added to it (fluorescent one, for example) and inspect the outside of the box bottom with an endoscope under UV illumination, but the lathe health insurance doesn't cover it. Obamacare, you know... And the patient refuses to pay. :)

Speaking about it, I may come to using my snake USB camera to examine the external part of the box bottom. I'm not too optimistic, considering the quality and maneuverability of such a rudimentary endoscope, but it may be worth trying. I rigid 45-90-degree one would be more suitable for the task.
 
The access to the box interior is extremely limited. Besides, I won't be able to see the result of the air blowing because there is no visual access there.
One watches for the oil pushed-about on the OUTSIDE, Pilgrim...

(unless it's some kind of a bottom fracture, which is somewhat less likely, although possible).
I suggested an internally damaged casting - near a bolt hole for instance from some long-ago "repair job" - largely because Monarch has NOT seen the problem.

Keep in mind that there were quite a few long-serving Monarch Machine Tool veterans that initially staffed Monarch Lathe, LP, that at least a few of them read PM as well, and "You can't beat the experience".

IOW - you don't seem to have a common or ordinary source for the leakage described.
 
One watches for the oil pushed-about on the OUTSIDE, Pilgrim...
As I mentioned, the areas outside of the box where you can expect the oil to be pushed out are hidden from the view. The bottom of the box where it most likely happens is not visible. I may try to examine it with an inspection camera inserted between the gearbox bottom and the pedestal top.

None of the places I can inspect directly with my eyes have a significant oil seepage (although I'm still watching the areas around the shafts).

On top of this, limited access into the gearbox itself will not permit any targeted air blowing or visual guidance.
 
As I mentioned, the areas outside of the box where you can expect the oil to be pushed out are hidden from the view. The bottom of the box where it most likely happens is not visible. I may try to examine it with an inspection camera inserted between the gearbox bottom and the pedestal top.

None of the places I can inspect directly with my eyes have a significant oil seepage (although I'm still watching the areas around the shafts).

On top of this, limited access into the gearbox itself will not permit any targeted air blowing or visual guidance.

Well....Hell....

How's about a good flush, drain, solvent wash and dry-out, then trying to see if red Glyptal will find and seal the leak? It actually LIKES being applied in multiple coats, starting-out thinned (with Xylol/Xylene IIRC).

Over its long history, probably as much of it has been used to coat cast-iron - gearbox interiors especially - as has gone onto electric motor windings. Damned few lubricants will bother the stuff. At all.
 
Thank you Bill. I'm very hesitant to use solvents there because of bearings. And applying Glyptal without taking everything apart, first, and not even seeing where it goes doesn't sound right to me.
 
Start cleaning. Clean the outside of that thing and the floor so there are no signs of oil on the outside of it or on the floor. Then come back in an hour and see where it has oil on it. If it's leaking as bad as it sounds, you will be able to follow the fresh oil streaks right to the leak. And you will have a clean machine to work with.
 
Actually, I started with this when I noticed the loss of oil initially. One hour is not enough. It's more like one or two weeks.

And the areas where I'm able to see the oil was described in the first and third paragraphs of my original post. The exact spot on the gearbox where it leaks from is not in any area that can be directly seen by eyes.

I do have something in the shafts area, but it doesn't appear prominent enough to me yet.
 
Think about it as a leak in an oil-pan in your cars engine. It is probably a worn seal or gasket. Call Monarch again and ask for a manual or paper that describes how to remove the carriage from the saddle. There are small oil distribution lines in there too that feed the drive shaft bushings, cross-feed screws and cross-slide, maybe one is rusted and your shorting the rest of the ways or carriage. All this talk and no answers. Just bite the bullet and do it the right way. If you have a good mechanical ability and I suspect you do, you CAN do it. Please post some photo's and the procedure so future generations will know what to do :-) Rich
 
Rich, it's not the carriage. The leak is from the gearbox (feeds, etc.) located below to the spindle gears compartment. The carriage would be easier for me to handle. I've done it before.

And, unfortunately, I was told that Monarch doesn't have any service manuals for the lathes. This was my first question when I called them.
 
Thank you Bill. I'm very hesitant to use solvents there because of bearings. And applying Glyptal without taking everything apart, first, and not even seeing where it goes doesn't sound right to me.

Glyptal, brushed, not sprayed, doesn't exactly volunteer to go walkabout - it will be on casting surfaces where put, and.. seep into seams rather than gears or bearings.

A bit of small diameter tubing you can bend, head and bristles chopped off a handkerchief assortment of "artist's" brushes jammed into the end of it, and you can do that by touch and feel where not visible.

Try it first with nothing on the brushes - you need to make up more than one - to vet the "reach" and see if it makes sense in this application. "Dental" mirrors - plastic & metal - and "snares" made from soda-straws or metal tubing plus thin cord, have been in my toolbox for the better part of 60 years as well. I have not YET needed fibre-optics, but they are tempting, too.

Small money. Not a lot of time. Low risk. Just might sort the problem cheaply enough.
 
Bill has already mentioned going at it with air and sound.

What about an ultrasonic leak detector? They detect the turbulence that occurs as gas escapes through a small orifice. You'd need to drain the oil, lightly pressurize the gear box (would 3 psi create other problems and leakage paths?), and somehow get a probe near the leak. For this application, a stethoscope with a fine tube as a probe might be just as good, or better. With the right piece of brass tube, I'd think you could survey the interior of the gearbox bottom via the drain orifice. Though it may not be practical to presurize the box while it is installed, due to other escape paths.

Jumping ahead a bit, how do you intend to repair the leak? It seems likely that the repair will probably require tearing it apart.

I once picked up a scrap cast aluminum timing cover for a 5.0L Ford from work. It looked pristine, and had come off a torn down test engine. It seemed a much better replacement to my corroded original. The new piece leaked coolant once in service. I re-did the install once, on the assumption I had somehow buggered the gasket. It leaked again, from an invisible crack. It'd be a shame to tear your lathe apart but not resolve the source of the leak.
 
You won't believe it, but yesterday this same idea came to my mind: pressurizing the box and using ultrasonic leak detector. But in order to get under the box, I'll need to open the oil sump compartment that will expose openings into the box. This will not permit any meaningful pressurization.

Theoretically, if I had six hands and eight eyes, I could combine Bill's idea of air blowing with scoping the areas underneath the bottom. But the box content wouldn't allow any meaningful air nozzle navigation inside the cavity. Besides, based on the relatively low oil loss rate, the main suspect is a leaking gasket which will hardly be detectable by this approach anyway.

Adding some dye into the oil may be beneficial though... But I don't have experience with such oil additives and don't know what can be used.
 








 
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