Old motor, grease or oil

[quitereal]

Hey folks, I have an old british thomson houston motor that has a grease nipple on one end and slotted plug on the other. Do I give it grease or oil?

I already learned the not every nipple is for grease lesson...

 

[Larry_C9]

My best guess is that there is a ball bearing in the end with the grease fitting so it should have some light grease. The other end looks like it probably has a bushing so some SAE 30 oil would be good. This is only an educated guess from looking at the pictures.

 

[quitereal]

I was thinking on it overnight, I figured if it wants oil theres gotta be a felt in there right? So I popped both ends - there was grease behind the nipple, however it turns out to be an aftermarket nipple with the wrong threads. Nipple is 1/8 npt, the hole and the plug on otherside is something coarser.

Nippleside:

Backside has no felt:

So still not real sure. The instinct is see a nipple = grease. Any motor in the last 50 years = grease. But that nipple isnt original...

 

[chipBit]

Sometimes, when you change bearing from open race to sealed. To eliminate confusion, grease nipples are removed and plugged.
In your case, DE bearing could be open and NDE is sealed.
This is normal ship practice.

 

[quitereal]

I cleaned the grease out of the nip side and lo and behold there was felt at the bottom. Going with oil on this one. Side note the caps and holes are 3/8-18 thread, which is odd. No npt grease zerk would ever really fit.
I just want folks to know when fiddling with old machine tools that grease zerks are a trap

 

[Martin w]

That is old. Back when they were built to last. Is that on your Cincy mill?

 

[quitereal]

Aye, the 5hp main motor. So 1930s.

 

[garageguy]

Being made in England could the thread be witworth or BSF , BSPP ? I would think oil is correct