[Healeys] Existential Question on Bearings
m.g.sharp at sympatico.ca
Thu Aug 10 21:48:23 MDT 2017
Bob, I just finished doing exactly that on my BT7. I last replaced them in
the late '70s, as you say, out of principle as I don't ever recall an issue
with them (they have been re-packed a few times since then!). I cleaned
them thoroughly and carefully inspected them, including the outer races in
the hubs. I also turned them in my hand (don't spin them fast when dry -
it is not good for them), applying some pressure so the rollers ran on the
inner race to see if I could detect any rough spots. They seemed fine so
after setting up the end-float I packed them full of grease and put 'em back
in. I meticulously follow the procedure in the manual: shimming between the
bearings to get zero end-float. I do this set up before packing with grease
as to really feel any play in the bearings. I do just spray them with WD 40
so there is some lubricant on them when they are turned as part of the
set-up, but then I wash that off before packing with grease.
From: Healeys [mailto:healeys-bounces at autox.team.net] On Behalf Of Bob
Sent: August-10-17 1:24 PM
Subject: [Healeys] Existential Question on Bearings
We've all probably lost a few of ours due to the state of the world, but I'm
referring to the important ones; i.e. wheel bearings, hub bearings,
gearbox bearings, etc. I'm fixing to clean, inspect and repack my
front wheel bearings in the coming days, and I'll likely be faced with a
decision. I don't recall exactly when I last checked them, but it
probably was 50K miles or (much) more. The 'existential question?'
Well, should I replace the bearings on principle--even if mine have given
many years and miles of faithful service, and will probably appear
pristine--on the presumption that they have a limited lifespan and are
getting closer to that limit?
Years ago, this would be a 'no-brainer,' as the younguns say: Given the time
and effort required to remove brake calipers/drums and pull the dust cover,
cotter key and big nut, I would have probably replaced bearings and races,
especially if they had 100K miles or more on them (even with the hassle of
getting end float correct). Now, I don't think that's a given since the
quality of parts is more suspect than ever.
Last time I replaced my rear wheel bearings--a no-brainer as one was
obviously toast--the new ones from Moss came labeled 'Made in Italy.'
That was scary enough--although the Italians are known for some pretty cool
engineering and design--but I suspect anything I can buy now will
possibly (probably) be labeled 'Made in China.' I'm sure, someday,
China will produce quality products--they may even come up with some of
their own, instead of buying/stealing IP from the US and Europe--but I don't
think that day is here (lest you think I'm just being my normal bigoted
self, I once had an airplane partner who was in charge of QA for iPhones
being built in China--suffice it to say you wouldn't want to expose small
children to his stories--and I happened to be working a contract for Space
Systems Loral when they got busted for, uh, 'lending'
missile guidance technology to the Chinese*). I don't know for a fact,
but I suspect even once-trustworthy name brands like Timken are
'offshoring'--a nicer-sounding word for sending local jobs overseas--some if
not all of their production.
So, when I remove and clean the bearings, and closely inspect them and their
races, do I replace them 'on principle,' or put the old ones back in after
thorough cleaning, inspection and repacking?
* SSL was using Chinese rockets to launch comm and weather satellites, and
the launches failed fairly regularly, so SSL helped them out with guidance
and stability technology. Of course, there's no way the Chinese would apply
that same technology to make their ICBMs more reliable and accurate; that
just wouldn't be nice, would it?
Now, it appears Boeing--please say it ain't so--is going to give decades of
engineering effort and experience to the Chinese for the 'privilege'
of building their planes cheaper there. No way that will come back to haunt
them--and Airbus--nope, no way.
Support Team.Net http://www.team.net/donate.html Suggested annual donation
Healeys at autox.team.net
More information about the Healeys