Old GE Motor maintenance - help

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Tereci

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California
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Software Engineer
Hi,

I am restoring and old lapidary saw. It came with General Electric motor 5xbh00dd that I cannot find any details about. Specifically I am trying to determine how to re-oil it. Would anybody know?
It says "Reoil with S.A.E. 10 oil". As far as I know there is no SAE 10 oil, only 10W. Would you know what would an appropriate oil for this motor be? I don't want to break it.
And second question it doesn't say how to reoil it. Am I guessing correctly that the hole on the side of the motor is the reoiling port? The same one is on the other side of the motor.
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Any advice is welcomed.
Thank you,
Tereza.
 

drcampbell

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"10W" is a winter designation. (maximum pumping viscosity of 60 Pa∙s at -30°C)
Unless your motor operates in a freezer, it's meaningless. (and if it does, it's the wrong oil)

Look away from (gasoline/Diesel) engine oils ... commonly, wrongly called "motor oils" ... which are optimized for 100°C and look for an (electric) motor oil, optimized for 40°C.

If I recall correctly, the spec for SAE viscosity grade 10 called for a maximum viscosity of 5.6 mm²/s at 100°C, which would probably be in the neighborhood of 56 mm²/s at 40°C. Look for something near ISO VG 56.
 
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ActionDave

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An area Motor shop told me over oiling kills more motors than under. Oil doesn’t play nice with motor windings.
I don't think oil does anything to motor windings, however, over oiling does nothing of benefit hence my comment that one bottle of oil should last the life of the motor.

Grease, on the other hand, is a big problem. Maintenance guys and farmers pump grease in the berings like a bar fly dousing his cologne and it makes the bearings wear out faster.
 

PaulMmn

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I don't think oil does anything to motor windings, however, over oiling does nothing of benefit hence my comment that one bottle of oil should last the life of the motor.

Grease, on the other hand, is a big problem. Maintenance guys and farmers pump grease in the bearings like a bar fly dousing his cologne and it makes the bearings wear out faster.
One thing over-greasing bearings does is squeeze out the -old- grease, along with metal particles and other crud that add to the abrasion. Let the grease oooooze out of the bearing to prove you really filled it up! :) I don't know if it makes bearings wear out faster or not...
 

kwired

Electron manager
Location
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One thing over-greasing bearings does is squeeze out the -old- grease, along with metal particles and other crud that add to the abrasion. Let the grease oooooze out of the bearing to prove you really filled it up! :) I don't know if it makes bearings wear out faster or not...
But with most general purpose motors it will ooze out inside where it can't be seen.

Also taken many motors apart that had a grease fitting installed, but the bearing was a shielded/sealed bearing and grease never got into it anyay. One thing to see it happen with a bearing that had been replaced, but seen it many times on motors that still had original bearings installed.
 

hbiss

EC, Westchester, New York NEC: 2014
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That hole to the left of the bolt head is the oil port. There should be one at the front also. I would clean them out first. Your local hardware should have electric motor oil, but any 10 weight motor oil will do. It's not critical and you won't damage anything unless you over oil. A couple of drops once or twice a year or so will do fine.

These are just sleeve bearings on this little motor, not ball bearings requiring grease.

patonsparky said:
An area Motor shop told me over oiling kills more motors than under. Oil doesn’t play nice with motor windings.

Over oiling causes oil to run out inside the motor making a mess. It won't hurt the windings but (with this type motor) it will get on the centrifugal starter switch contacts causing them to arc which will destroy them after awhile. So if you have a motor that won't start, look there for the cause. Replace the switch and degrease the motor.

Another problem over oiling can cause is it softens the rubber mounts if it gets on them causing the motor to sag and become misalligned to a directly coupled load. This destroys the mechanical coupling.

Anybody that services hydronic heat and circulators is all too familiar with this.

-Hal
 
Look away from (gasoline/Diesel) engine oils ... commonly, wrongly called "motor oils" ... which are optimized for 100°C and look for an (electric) motor oil, optimized for 40°C.

If I recall correctly, the spec for SAE viscosity grade 10 called for a maximum viscosity of 5.6 mm²/s at 100°C, which would probably be in the neighborhood of 56 mm²/s at 40°C. Look for something near ISO VG 56.

Definitely, engine oils are made for combustion engines and all their problems. If you need to lubricate something, use a lubricating oil. Beware that the viscosity scales for different types of oil don't match up- IIRC 90 weight gear oil has about the same viscosity as 30 weight engine/motor oil but has very different properties. (A shop I sometimes work in has a range from turbine/sewing machine oil to 600 weight steam cylinder oil.)

And say it with me- WD-40 is not a lubricant, never was.
 

ActionDave

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One thing over-greasing bearings does is squeeze out the -old- grease, along with metal particles and other crud that add to the abrasion. Let the grease oooooze out of the bearing to prove you really filled it up! :) I don't know if it makes bearings wear out faster or not...
No. You are part of the problem. Over greasing put more pressure on the metal parts of the the bearings and makes them wear out faster.
 

kwired

Electron manager
Location
NE Nebraska
Definitely, engine oils are made for combustion engines and all their problems. If you need to lubricate something, use a lubricating oil. Beware that the viscosity scales for different types of oil don't match up- IIRC 90 weight gear oil has about the same viscosity as 30 weight engine/motor oil but has very different properties. (A shop I sometimes work in has a range from turbine/sewing machine oil to 600 weight steam cylinder oil.)

And say it with me- WD-40 is not a lubricant, never was.

sure it is, just not ideal for this kind of purpose. You could put water in there and it probably lubricates as well, but also likely to cause other problems longer term.
 

Tereci

Member
Location
California
Occupation
Software Engineer
Thank you all for the replies! :)

2 follow up questions. I found several different types of "Zoom Spout" Oiler from different brands, are they all equal or do I need a specific one? E.g. "Supco MO 98, finest all purpose oil", "J Oiler with turbine oil", "AlbaChem Lili White lubricant Stainless Sewing Machine", "Dial Finest All Purpose oil".. to name a few. I don't see anywhere on them any ISO marking for viscosity.

And the second question - any tips on cleaning those ports before I put the oil in? I can probably clean the top part with a toothpick and a tissue or a handheld vacuum but won't get the deeper and narrower parts. Will I do more damage if I drop the oil down into that dusty port than if I don't re-oil it? The motor currently runs, I just know it's really old and hasn't been maintained.
 

ActionDave

Chief Moderator
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Location
Durango, CO, 10 h 20 min from the winged horses.
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Licensed Electrician
Thank you all for the replies! :)

2 follow up questions. I found several different types of "Zoom Spout" Oiler from different brands, are they all equal or do I need a specific one? E.g. "Supco MO 98, finest all purpose oil", "J Oiler with turbine oil", "AlbaChem Lili White lubricant Stainless Sewing Machine", "Dial Finest All Purpose oil".. to name a few. I don't see anywhere on them any ISO marking for viscosity.
Zoom Spout is a brand name and is really easy to find. Any light weight, non detergent oil is fine. No motor oil. Sewing machine oil, 3 in 1 oil, household oil, etc is all fine.
And the second question - any tips on cleaning those ports before I put the oil in? I can probably clean the top part with a toothpick and a tissue or a handheld vacuum but won't get the deeper and narrower parts. Will I do more damage if I drop the oil down into that dusty port than if I don't re-oil it? The motor currently runs, I just know it's really old and hasn't been maintained.
Pick the crud out of the top of the port with a toothpick and don't worry about anything else. You won't do any damage putting drops of oil in a dirty port. Down at the bottom is some "sawdust" wicking that soaks up the oil and keeps the bearing lubed.
 
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