[Milsurplus] NAVY type A grease?

[Michael Hanz]

You may be overthinking this.  If it's a motor or generator, the best 
thing out there is a fairly recent Mobil development using a _polyurea_ 
thickener that wasn't around in WWII.  (Otherwise they /would/ have used 
it - it has some very useful qualities.)  Get a tube of Mobil SHC 
Polyrex 102 EM (Electric Motor) grease and stop worrying about it.  Make 
sure the tube says EM - Mobil has a number of versions of SHC Polyrex 
102 available but none of the others are specifically optimized for the 
speeds and loads of electric motors and generators.

https://www.mobil.com/en/lubricants/for-businesses/industrial/lubricants/products/mobil-shc-polyrex-102-em 
has a _lot_ of data on it.

You might consider using a bearing greasing tool to meter the grease in 
- you may have a problem getting a repeatable amount of any grease in 
there by hand.  At least that has been my experience with countless 
dynamotors and rotary inverters over the years.  One I made for my own 
use is shown at https://aafradio.org/garajmahal/Dyno_greasing_tool.jpg

It's a tough job, but somebody has to do it...  😁

- Mike  KC4TOS

On 1/10/2023 12:29 PM, Ron De Silva wrote:
> Hopefully there is an ex Machinists mate around.?
>
> I have searched everywhere on line and with fellow sailors with no 
> success.
>
> In rebuilding the MG set for my TDE, I have run into some issues.
>
>
> Electrically everything is fine and working perfectly.....BUT the 
> simple process of putting in 4 new bearings and packing them??.
>
> I had no idea what was Navy type A grease?
>
> Sodium.base,Calcium base? I doubted it was lithium.
>
> What viscosity,?Was it traditional NLGI grade 2 grease? NLGI grade 1?
>
>
> Anyway, after tearing down and cleaning the motor and original  
> generator last February. I replaced all bearings and packed them all 
> with red lithium NLGI grade 2 grease which was standard up until 30 
> years ago on electric motors.
>
> The TDE ran fine for a month...but then the armature went bad and I 
> was looking for a new generator
>
>
> I was lucky enough to find a nice one and tear it down,cleaned up 
> everything.Baked in the oven again for drying...then meggered 
> again..All great.. Then a new coat of glyptol on all the windings  
> Works fine.
>
> But, I have had issues of one  bearing running 10 degrees warmer than 
> the other.
>
> And also it's very difficult to get the correct amount of grease into 
> the bearing cups.
>
> The manual procedure is opening the relief plugs,pumping in new grease 
> at the fill fitting until old grease is purged from the relief port.
>
>
> Then run a half hour leaving the drain open to let excess grease 
> release pressure. Then close off.
>
> If you pack things to that extent..all 4 bearings. Motor and generator 
> , will fling grease off the grease shields for an hour before it stops 
> throwing any more...and appears to run fine afterwards.
>
> I tried NLGI grade1 (lower viscosity) in that warmer bearing careful 
> not to overpack with grease which naturally causes overheating.....but 
> no change AND it really flings the lighter grease.
>
> I finally pulled generator apart. Cleaned and removed both old 
> bearings and put in new bearings.
>
> But I have no idea at this point what to do but lightly pack with red 
> lithium NLGI 2 grease again.
>
> Anyone with an idea of what mystery Navy Type A grease was in 1942??
>
>
> Thanks,Ron,NU6F.
>
> https://youtube.com/shorts/x60N-vZ_yr8?feature=share
>
>
>
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-- 
Michael Hanz - KC4TOS
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