CB500/4 Countershaft Bearing dimensions.

[Gixxer-18]

Hi guys, I've stripped down my gearbox and found two different size bearings, though the parts manual says they are both 5205 bearings which have a 52mm Dia.  One of them is a 5205HS   ( HS for high speed ) I know from previous posts that there was a misprint in the 500/550 manuals. I have sourced the 5205 52mm bearing, p# 91002-286-008; there seems plenty of those about,  but the countershaft bearing #91002-283-003. (57 mm dia with snap ring groove) seems unobtainable. I've tried googling the bearing, and no-one seems to have them anymore. The bearing I have is a NACHI 258651 25mm inner dia, 57mm outer dia, and 24mm wide. The snap ring groove is central, 2mm wide and 1.15 mm deep. The experts may correct me, or confirm these measurements! Fortunately, mine is in good condition. I have seen countershafts for sale with this bearing fitted, but none available singly.
I've found out that 5205 as you would expect means 52 mm outer dia, and the 05 means 25 mm ID,
so I tried googling 5705, no luck.

Honda must have had thousands of these bearings made, possibly even millions! So where have they all gone?
Any ideas?
Also, can anyone explain what B/brg N/rad N/com on CMSNL website mean? I'm guessing ball bearing, nominal radius, but I'm stumped on N/com!
Regards
Nigel.

[AshimotoK0]

Unfortunately Yamiya don't do 500/4 parts but they are definitely the cheapest source for grooved special Genuine Honda bearings for 400/4 and CB750.
The high speed version is suffix C3 if you look ina bearing manufactures book like SKF or Timken. I have heard of people taking the ungrooved version and grooving it (man ). Someone on here I am sure has done it. The 286 bearing is a CB250/350K bearing, so that's why it is common (one of the 500 selectors is the same PN as CB250/350K and so is the shift drum). The CB250/350K parts book is in my Dropbox link:

Here:   https://www.dropbox.com/s/2ohbdtqh5nvgvvf/Combined%20Honda_CB350_Parts_Catalog.pdf?dl=0

UPDATE : Bryan is correct..... in the '69 parts book for the CB250K, a similar, separate shaft and bearing was available. Then they discontinued the shaft only and sold the shaft/bearing assembly together ..... 'cos the bearing is a tw*t to remove.

[Bryanj]

The reason its difficult to find separate is that all the parts suppliers i knew only stocked the shaft with bearing, also its a real swine to press off

[Gixxer-18]

Thanks Ash, I've looked at your parts manual you kindly supplied as a pdf, but the manual shows both bearings to be the 5205 52 mm size, and when cross referenced with the snap ring those are both shown to be 52 mm. Too. I have two new bearings of that size; one for my 350/4 and one for the 500/4.
The one I'm after is the 57 mm diameter, it is available with the shaft, but with it being so rare the price is high too... I might just have to bite that bullet 😟
I wonder if the members who have grooved a new bearing could comment on how they achieved that, and whether the new groove was machined or ground? I expect the swarf to be a hindrance, and with the outer race being hardened did that pose any difficulties?

Finally, what bearing did you use?  I've tried googling the dimensions for a double row 25x57x24 with shields and got nowhere, so thought about a sleeve OD57 ID52 24wide with a cruciform cross section and split like a white metal big end/ main bearing to locate one of the 5205HS bearings as the ID of those is 25 mm and does the same job.
Do you think that is a possible solution? The only problem I can think of is the 5205 width is different.
Regards
Nigel.

[AshimotoK0]

You could try these .. pretty sure they do that size, not so sure on C# high speed but worth a try !

http://www.hoffmannbearings.co.uk/index.html

[Gixxer-18]

Thanks Ash again, hoffmann (Orinoco bearings) are very helpful people, and are looking into it for me. I will have an update by Friday they say.
Nigel.

[AshimotoK0]

That part is a CB450K1 part and is used in the CB450K1 gearbox. You could try the guys on Hondatwins.net. I will post on there for you.

[Gixxer-18]

Thanks again Ash, I'm on Hondatwins too, I have CL450 and a CB360 too! Gonna check my manuals for that part# too.
Nigel.

[Gixxer-18]

Thanks Oddjob, somewhere in Japan is a small warehouse with lots of little red boxes with a wing on the side and marked 91001-283-000; made by NACHI, and stamped 258651!
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Nil desperandum,
Regards Nigel

[Gixxer-18]

Hi Oddjob, I'll keep you posted, I am following a lead in Japan. If they become available I'll let everyone know. I have found 25x57x28 double row axial bearings, but without the snap ring groove, with rubber seals, and these retail about £300 + VAT! The right diameters but too wide for our needs.
Regards
Nigel.

[Gixxer-18]

That's good news Oddjob, my contact has just asked how many do I need! I'm still waiting to hear back! If they have got them I expect they will be a similar price.
The next thing is they mentioned that they could consider getting these bearings made as a run. They couldn't tell me a price for that yet, but it wouldn't be too high, minimum run though is 1000 pieces.
 Next question is how many forum members want one of these bearings?  Actually want, rather than would like? I know you and I want one, and I think Ash would want one too,  I'll wait to hear from the bearing factors Monday, and keep you posted.
Regards
Nigel.

[AshimotoK0]

What's wrong with your original bearing Nigel. Has the engine done high miles? Mine has done 22k and by the looks of the top end it's been looked after so kind  of hoping I won't need that bearing. Or are they prone to failure on the 500? What I did with my CB750K0 was to buy a really low mileage gearbox / primary sprocket assy. which cost me about 70 quid after customs, shipping etc (in fact I bought two so if anyone wants to buy one for what I paid).

[Gixxer-18]

Hi Ash, sorry for the delay in replying to your question, there's nothing wrong with my bearing, but I have the chance to get some made, by a bearing manufacturer, In small quantities. They want a bearing to measure before they quote, and I was a bit reluctant to send them my only bearing. I've sourced a scrap countershaft with the bearing on it, which they will have later this week, and I'm waiting to hear what they will cost. If they're reasonable I'll get some made.
Regards,
Nigel.

[AshimotoK0]

Picked up a  Genuine Honda   91001-283-000 today and he confirmed it is centre grooved. Guess I need to check with him it's 57 mm Dia before he ships it as a bit confused as it doesn't have the -003 suffix. given in the Cb500/4 manual and is listed for a CB450 up to CB500T. Are you out there Nigel and Oddjob (Ken).  May not even need one but with the rarity factor I thought I would take a punt as it was in the UK.

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[AshimotoK0]

Sounds like I am in luck ... seller measured it and its 57mm Dia.