Rear spindle bearing oil level question

I noticed the oil level dropping almost as fast as I could put it in. I popped the cover and found the oil is coming out of a hole circled in the pic below. The hole appears to be lower than the nominal oil level. Should there be a plug in this hole?



Ryan

Hi Ryan,

I've been scratching my head over this one. My best guess it that it's an overflow drain for the rear bearing reservoir, but I don't have one. Here's a photo of the same area in my headstock:


There are two round spots on the casting in roughly the same area as your hole, about 1" below the shelf formed by the top of the rear bearing reservoir. I don't know if it's left over from change to the casting or some other artifact. Here's a blow-up:

As best I can tell, they are at about the level of the center of the sight glass. I measured the center of the sight glass to be 5.0" below the machined surface for the top cover. The shelf is 4" below the machined surface.

I'm surprised how different your headstock is from mine. Here's another view showing more of the upper part of the headstock:

Note the differences in the outer sleeve bearing for the left-hand threading gear on the spindle. Mine is looks like bronze, yours is a white metal alloy of some sort. You have at least three counter-sunk holes on the sloping surface of the bearing to allow oil into the interface with the gear; I have none, and I have no idea how oil gets into the bearing. The casting over the bearing itself has also changed. Mine has a rib that goes off at a 45 degree angle to the rear of the headstock; yours is round. In your photo I see another oil hole next to the large set screw that retains the bearing; on mine the rib forms an area that collects oil with no way for it to drain out, ditto over the bearing for the other gear.

If my notes are correct, your machine was built 4-1942, 19 months before mine. My headstock has a casting number of EE2527; I see a 27 cast on a tag inside your headstock. Could you check the casting number on the left end of the headstock, under the belt cover? It should be in the rear, near the bottom, just above the drain plug for the center reservoir.

The leakage from the rear bearing reservoir has always perplexed me. (A number of people have commented on this over the years.) I can fill the reservoir to the top of the glass and it will drain down pretty rapidly, over a span of 5 to 10 minutes to be a little below the center of the glass. Overnight it will be below the bottom of the glass. As best I can determine, it's seeping out around the gear and/or spindle. It's definitely going into the center reservoir.

Does your oil level stabilize somewhere or just drain down?

Cal

I took some better photo's today.

Cal it looks like you do have some type of hole, just much lower in your first photo. Do you know what that's for?

Here's a better shot top down, the casting is different compared to yours.


I have these numbers cast into mine, outside: EE 2527



And this on the inside:



I have a small maybe 1.5" by 2.5" access panel on the back of the head stock. I took it off and there was the rear bearing reservoir. Here's a close up. You can see the hole in the back of the cavity:



I made a white line at the same level as the sight glass level, you can see it on the right side of the machined edge of the casting. It's about even with the hole on the left side...



The hole has no threads, so I can assume there is not a threaded plug to go in there. One thing I thought about today, my tail stock end is pointed towards my garage door, thus the lathe is not level. I wonder if any oil would leak out of that hole if the lathe were level?

The other think I can do is plug the hole with a well nut?

I'm going to get a more precision measurement of the hole location relative to the top of the headstock and compare that with the oil sight glass level line. My guess is that the hole is an over flow, and the slope of my garage floor is causing the oil to flow out.

Ryan

Hi Ryan,

This is very interesting (well, at least to me). We have the same headstock casting number, yet very different castings. Here's a photo of the drive end of my headstock:


I'm sure now that your mystery hole is an overflow. I bet that if you level her up you will find that it's just above the center of the sight glass. Try measuring up from the bottom edges of the casting to confirm this. I suppose you could plug it if you like; they obviously thought my machine could do without it. As far as I know there are no overflows for the front reservoir, but it's possible that there was no need as excess oil could flow over the top of the oil deflector (there should be about 0.020" clearance there). There is no oil deflector on the rear bearing, nearest the center.

The drain hole you spotted in my headstock connects to the tubing you can see in the photo, above the casting number. It's the overflow from the center reservoir, the tube routes to the drain hole in the base, directly below the spindle. I'm surprised you don't have one.

I don't have the access cover for the rear spindle reservoir. (I didn't know that there was such a thing until now.) I don't know if the difference has to do with the fact that I have the factory lever collet closer, or if this is part of some cost reducing change made during the war. It may be that they had to get rid of the cover to allow space for the mounting bolts for the upper cover. (Instead of having one large cover for the gearbox and headstock belts, I have two and the upper cover is held on by a dowel pin and large bolt on either side of the spindle.)

Anyone else?

Cal

Cal,
Can you post some pics of the rear 2 piece cover? How dooes the cover work with the collet closer mount?

I also have a collet closer, but not the factory one. I'm not yet sure how I am going to mount it.

How long is your draw tube? Mine is definitely too short, I'll need to fab an extension.

Ryan

FWIW, my casting also has the square cover to the left of the spindle.

Thanks Kirk. Your machine is about the same age a Ryan's, so I'm not surprised. I think that feature goes all the way back to the Sundstrand drive machines, I just hadn't known about it. It will be interesting to see if any machines my vintage (11/1943) have it.

Ryan,

Here's an old photo that shows all three drive-end covers:


The top covers bolts to the headstock. The bottom cover sits on three pins and is just about the same as those on other machines. The middle cover has to go on last and slides in on top of the base and the bottom cover. It's held in place by two threaded knobs that thread into tapped holes the top and bottom covers. The only difference in the bottom cover is the shorter center strip and tapped hole for the middle cover.

Here's a link to a thread that has more information about the lever collet closer:
http://www.practicalmachinist.com/vb/showthread.php?t=99714

I think a lever closer can be mounted directly to the headstock with the existing covers. I believe there is an example of that in the thread.

Cal

The Sundstrand machines have the access cover for the rear oil galley. There is an oil drain for the headstock, but no overflow. Overflow makes its way out the feed/thread shaft hole on the front of the headstock.

"We have the same headstock casting number, yet very different castings"

Monarch appeared to use the same pattern number on quite different patterns.

The tailstock bottom casting for the 12.5" 10EE ("new height") is 0.5000" taller (finished) than the bottom casting for the 12.0" 10EE ("old height"), but the pattern numbers are the same, that is, the "EE-xxxx" which is found on the castings are identical.

rimcanyon said:

The Sundstrand machines have the access cover for the rear oil galley. There is an oil drain for the headstock, but no overflow. ...

Click to expand...

This is the drain for the center reservoir? I assume there is no drain for the front spindle bearings?

Cal

This is the drain for the center reservoir?

Click to expand...

Yes, that is correct. There is no drain for the front spindle bearings.

I can put this thread to rest now... I believe I have worked out what purpose that hole exists for....

In this picture above



Notice the two holes on top at the left of the image...

These two holes drain into the rear compartment....

The horizontal hole that is drilled between the two compartments, is a drain hole drilled at the upper level limit or the rear compartment.... I believe it is supposed to work that oil being thrown around the middle compartment finds it's way into those two holes, gets transferred to the rear compartment, then back through that drain hole...

What actually is happening is oil in the rear compartment is through turbulance of the bearing and spindle sloshing around is moving to the middle compartment but not as much is being transferred back to the rear compartment...

Essentially it is a design flaw, that was rectified very soon after....

What I have done is fill most of the hole with automotive silicon sealant, with just a small gap left on top, should the oil level get way overfull it will drain back to the middle compartment...

thermite said:

AFAIK, those two holes, front and rear, adjacent the Allen-headed screw, on the TOP curve of the casting where the hubs for the drive PTO sit, communicate instead with the bearings FOR the threading drive take-off gearing, thence drain back to the centre sump, not into the spindle bearings or their reservoirs. If that is not so, it should be.



What am I missing?


Bill

Click to expand...

If your lathe headstock looks like the above (they changed them in 1942 IIRC) then put an air line into one of those two holes.... All the air goes into the rear compartment...

I stand by my claim...

I have this same problem and found this old thread where the discussion kind of ended. Did anyone find any further solutions to this or prove out the adjustable overflow idea? My rear bearing oil level goes from the full line to 1/2 or 1/3 very quickly. The center never becomes over full. The oil seems to mostly end up coming out the hole in the chip pan below the spindle. Mine has both the rectangular access panel and overflow tubing. Thanks

FortyFive said:

I have this same problem and found this old thread where the discussion kind of ended. Did anyone find any further solutions to this or prove out the adjustable overflow idea? My rear bearing oil level goes from the full line to 1/2 or 1/3 very quickly. The center never becomes over full. The oil seems to mostly end up coming out the hole in the chip pan below the spindle. Mine has both the rectangular access panel and overflow tubing. Thanks

Click to expand...

My rear spindle bearing also looses oil. This is a fairly common problem. I'm reasonably sure that what's going on is that oil is leaking out around/under the bearing sleeve that the threading gear runs in. The tolerance, as shown on a 1941 drawing, indicates that the sleeve can be as much as 0.0006" smaller than the bore in the headstock casting. I imagine that some sort of sealer was used when the sleeves were installed. Age or flushing the headstock with the wrong solvent could dissolve the sealer and allow oil to seep out. If you ever have occasion to remove the spindle, you can apply sealant to the sleeve. But I wouldn't tear the headstock apart just for that reason.

The reason that the oil is coming out under the spindle is that there is an overflow tube from the center headstock reservoir (mentioned in this thread) that is routed to that point.

Cal

Thanks. Do you just run it at the 1/2-1/3 where it seems to stabilize, or just keep pumping oil in it while using?

This is probably no use to anybody, but I will throw it out anyway. The original ( at least on mine) rear bearing has a hole in the middle of the race that should be installed with that hole down so it will be lubricated by that little resevoir. These "special" bearings as far as I know have not been available for many years and the replacement bearing has no hole. I think Monarch figured there was enough splash and mist in the heastock compartment that the special ventilated bearing and its special resevoir were superfluous. I don't put oil in that rear most compartment as it would only be for show and it leaks out quickly.

Good info, Daryl.

I fill the rear reservoir up before using the machine. Mine doesn't drain down quickly enough that I need to refill it during the day.

Cal

That is interesting. Thanks

I wish mine drained more slowly like that.