I need a bearing guru!

[drdano]

Hello folks!  Are any of you in the bearing industry or handy with figuring out the part numbers for bearings? 

I'm working on an OT transmission project in one of my motorcycle restorations.  I have available the OEM bearings, which are not marked on the transmission shafts.  I also have an aftermarket bearing kit for said transmission.  The problem is the bearings in the aftermarket kit will fit, but are a no-name off shore branded and since I'm knees deep in this thing I'd rather use some known-quality bearings now rather than take a gamble on potential future issues later.  The good news is, these bearings are marked with some sort of part number.  The bad news is I'm getting lost with how to map those numbers to something like SKF, Timken, Koyo, other known decent parts or if these numbers mean anything at all. 

Is there anyone who could help me out with this?  I do have access to the transmission case, shafts for making any measurements needed. 

Thanks!  -Dano

[Heo]

I have a SKF Bible somewhere ill try to find it
I will need to know the type of bearing ID, OD, and width

[drdano]

Thanks Heo!  Let me know if any of these match to something in your book.

Mainshaft

Small Bearing - Needle Roller
20mm I.D.
30mm O.D.
20mm Thickness

Large Bearing - Double Row Ball.  1.85mm snap ring groove on outer edge, 2.4mm from one side.  Marked as "Koyo 83424".
25mm I.D.
52mm O.D.
20.5mm Thickness


Count Shaft

Small Bearing - Needle Roller
20mm I.D.
35mm O.D.
15.9 (16?)mm Thickness

Large Bearing - Double Row Ball.  1.85mm snap ring groove on outer edge centered.  Marked as "Koyo 83425".
30mm I.D.
62mm O.D.
23.7 (24?)mm Thickness


Selector Drum

Support bearing- Needle roller, but one end is open, the other is sealed like a metal "cup"
15mm I.D.
22mm O.D.
20mm Thickness

[Heo]

Sorry cant find any of the bearings in SKF s main catalogue
It is a few years old though, I can try to call SKF in Sundsvall
Earlier the guy who worked there knew all you needed to know
i ordered a set of bearings by the number and he said..So you
are rebuilding a Model A rearend.. by the number of the bearings
but hes probably retired now but i give it a shot
What motorcycle is it?
The needle roller bearings are they with a inner race or roll directly on the axle?

[Cyclone Joe]

Here is the info link for SKF.  I checked the first bearing you provided info, and they didnt have the exact item you were looking for, but were close.  Try putting in a range to see what they have.

http://www.skf.com/us/products/index.html


For reference, Koyo is a Japanese bearing company and is a bearing supplier for auto manufacturers so I wouldnt be afraid to use them.  They've been around a long time.

Here is Koyo's catalog describing what the numbers mean. Sometimes they list the cross-reference to SKF and others, when applicable.
https://www.ibtinc.com/wp-content/uploads/2016/03/Koyo-Ball-Needle-Roller-Nomenclature-Guide-Co-Branded-IBT.pdf

Joe

[Heo]

Tried to call SKF today...spoke to a woman... probably at a callcenter
had no clue about bearings....just gave me the address to the page on
internet..thank you very much for calling this country is turning
to....I want those days back when you could call a person that knew
what they was talking about that knew the difference between a bearing
and ... an Airfilter

[drdano]

Thanks for the help guys.  I think the reason these bearings in this kit are taiwan made is because the big guys likely dont make them anymore.  I spent a good deal of time over the weekend on SKFs site using their calculator and didn't come up with a whole lot.  Heo, the needle bearings all ride on the transmission axles, no bearing races there.  On the good side, as I inspected the old bearings in the transmission, only two needed replaced.  One felt pretty rough, the other "cup" needle bearing was so packed with vapor honing sediment that I was scared I'd never get it all out...so I replaced it anyway.  Heo, this is a 1970 Yamaha XS-1, first in the XS650 series.  All the XS650's from 1970 to 1983 use the same bearings in the transmission.

[Heo]

XS1  Thats the paralell twin ? who had figured
in the 80s that someday someone would
rebuild Japanese bikes