Engraved Bearing Numbers

brent covey

New member
Jul 2, 1999
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Hi Arch

>Please check this out very carefully. I dont know the real answer yet
>but I have eaten a lot of crow over it. So a couple of people decide
>to put some markings on a bearing set with a Dermel tool. I am still
>not buying that this is the way a big company does business. I am not
>going to say it aint so----just want more info.

I'd be slightly suspicious also- actually, engraving additional fitment info
on a bearing with non-standard modifications to a 'stock' part is a common
practice in the industry. However, you're right, it can be easily
counterfeited. Do yourself a favour, ask for a copy of your manufacturers
catalog for your own research. I give my customers TONS of extra copies,
they can afford to hand a few out when theres someone interested. Most parts
suppliers also do this.

Generally, engineers designing a machine will do thier utmost to use a
standard, ordinary, already generally availible bearing rather than design
an altogether new one. After all, its easier for GM to machine the hole in
the transmission or wherever to fit something they already have a good price
on. On the other hand sometimes small modifications are made that are or are
not exceedingly obvious. A typical example would be machining a snap ring
groove into a regular bearing. If a small number of bearings are made from a
standard unit this way, they'll just engrave the extra codes on.

>This old farm boy knows the
>difference between a $5 disk bearing and a $15 one------BS.

HEhehee, you don't know how right you are! Always ask a disinterested and
impartial third party, such as the Tobacco Council when you need an unbiased
opinion. OK, maybe thats a bad example....

>I dont know
>if this applies here or not. You may be in the same boat I was when I lost
>big. Maybe you have more resources than I did. But chase it and find
>out what you can.

Well Arch, best we all can do is get together and compare notes frequently.
When theres a consistent trend in experiences, you know you're on to
something! Usually, anyhow;-)

Keep up the great posts - I always look forward to your points of view!

Brent Covey
Vancouver
 
Brent, check out this explanation by Tom Warner a while back. It's the
best one I've seen.

Cinnibar and Gateway sell 'matched' sets of Timken wheel bearings. These
include a
spacer ring that installs between the two cones whose thickness dictates
the assembled axial clearance of .095". The bearings will have this hand
etched on the spacer. They cost about $80 per set including inner and
outer seals. (CAUTION: Do not mix these bearing parts with any others as
this will change the clearances.)
Why is that important you ask? Good question. The outside of the hub
should measure from 2.0015" to 2.0020". The inside diameter of the bearing
that I have, measures 1.970". If I were to press that bearing on a hub
with maximum outside dimension of 2.0020" there would be a.032"
interference fit. Thats pretty tight and would reduce the axial clearance
of the bearing by some amount. How much? I don't really know, however the
cinnabar engineers have run tests on the various bearings with maximum and
minimum dimensions for both the hub, knuckle and bearing and decided that
in the worst case of each, an axial clearance of .095" is the minimum
clearance that can be safely used.
Cinnabars part number - 12351677
Gateway's part number -
Others to use in a pinch: (same bearings but not clearanced for our
application) Use at your own risk!!
Bower/BCA--------------------------- A-23
CR -------------------------------------- BR-23
J.C. Whitney------------------------- 38-0649-P
New Departure---------------------- S-77
Timken--------------------------------- 23
NAPA---------------------------------- Set-23
Federal-------------------------------- A-23

bdub
Central Texas

>Hi Arch
>
> >Please check this out very carefully. I dont know the real answer yet
> >but I have eaten a lot of crow over it. So a couple of people decide
> >to put some markings on a bearing set with a Dermel tool. I am still
> >not buying that this is the way a big company does business. I am not
> >going to say it aint so----just want more info.
>
>I'd be slightly suspicious also- actually, engraving additional fitment info
>on a bearing with non-standard modifications to a 'stock' part is a common
>practice in the industry. However, you're right, it can be easily
>counterfeited. Do yourself a favour, ask for a copy of your manufacturers
>catalog for your own research. I give my customers TONS of extra copies,
>they can afford to hand a few out when theres someone interested. Most parts
>suppliers also do this.
>
>Generally, engineers designing a machine will do thier utmost to use a
>standard, ordinary, already generally availible bearing rather than design
>an altogether new one. After all, its easier for GM to machine the hole in
>the transmission or wherever to fit something they already have a good price
>on. On the other hand sometimes small modifications are made that are or are
>not exceedingly obvious. A typical example would be machining a snap ring
>groove into a regular bearing. If a small number of bearings are made from a
>standard unit this way, they'll just engrave the extra codes on.
>
>
> >This old farm boy knows the
> >difference between a $5 disk bearing and a $15 one------BS.
>
>HEhehee, you don't know how right you are! Always ask a disinterested and
>impartial third party, such as the Tobacco Council when you need an unbiased
>opinion. OK, maybe thats a bad example....
>
>
> >I dont know
> >if this applies here or not. You may be in the same boat I was when I lost
> >big. Maybe you have more resources than I did. But chase it and find
> >out what you can.
>
>Well Arch, best we all can do is get together and compare notes frequently.
>When theres a consistent trend in experiences, you know you're on to
>something! Usually, anyhow;-)
>
>Keep up the great posts - I always look forward to your points of view!
>
>Brent Covey
>Vancouver
>
>
>
 
Hi Billy

Tom Warner's explanation makes good sense to me- I suspect the bearings must
be crushing down to a clearance in the 0.004" area perhaps.

I'm a bit puzzled about what makes five minutes work with a micrometer worth
all the extra money. Maybe in future another tool project would be one to
match bearings for end play. Anyone ever measured final installed end play
with a dial indicator on a set of Cinnibar bearings post installation and a
few miles driving?

Thanks Billy!

Brent Covey
Vancouver

>Brent, check out this explanation by Tom Warner a while back. It's the
>best one I've seen.