[Milsurplus] Don't pack the bearings

[Michael Hanz]

There seems to be a lot of debate about this, Charlie, but it stems from 
a lack of clarity on definitions.  Some folks equate the term "packing" 
to refer to the bearing and the entire housing under the grease cap 
(#1).  I think that view was fairly prevalent through the end of 1945, 
and is why the warning appears in numerous manuals of the period for 
high speed bearings, which are less forgiving than low speed wheel 
bearings with respect to "churn" heating the rolling surfaces.  Car 
manuals back before the war referred to packing the bearing and the cup, 
then slapping it all together, and that tended to get mentally extended 
by the GIs to the more modern roller and roller bearings suddenly being 
designed into everything.  Other folks consider packing as just for the 
bearing itself (#2).  I side with that view as well.

According to the manufacturers, the bearing simply needs all its 
_internal_ parts filled, which you can do by hand with a bit of patience 
but is faster and more complete with a conical bearing greasing tool.  A 
wipe of the inside and outside to leave a thin coat is then all it 
needs.  For those who think packing also includes the cavity (#1), the 
rule of thumb is bearing plus cavity should be no more than 1/3 full to 
allow for expansion without leakage.  In the final analysis, that ends 
up being fairly close in volume to the amount that the (#2) bearing 
packers prefer.

It sorta reminds me of the old ad about the "Tastes Great/Less Filling" 
argument.

      73,
  - Mike  KC4TOS

On 3/27/2020 9:22 AM, CL in NC via Milsurplus wrote:
> Does anybody know the reason it states on dynamotor instructions to not pack the bearings like you would a wheel bearing on a car axle?  Was it the type of lubricant that was available back in the era?  While I don't pack them like a car bearing in the palm of my hand, I do put enough modern synthetic lubricant from Lucas, in and around the ball bearings and the race it could almost be considered packed.  Have not had an issue with them heating up and oozing out the covers.
>
> Charlie, W4MEC in NC

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20200327/e0d3045c/attachment-0001.html>