Oil seals HELL

SMBH · Post by **SMBH** » Mon Jun 08, 2015 3:06 pm

So I have stripped the engine down and what I found was the left side main bearing (the large one) was moving in and out it seams the knock pin was intact there was a hole for the knock pin in the bearing BUT it had play in it I think it is the wrong bearing, the bearing is stamped 722901B now according to the parts book it should be 6306.

I have a bearing stamped 6306 S6HS Nachi on centre is stamped 3.0 PH Now this bearing is not new but seams ok I understand the 6306 are no longer in stock so can I use this bearing ?

Can I now turn to the other main bearing on the right side this has the number 620557H5Z Nachi and one side of the bearing is sealed is this right ?

If so what way round do's the bearing go on the crank sealed side facing the crank or outer ?.

THANKS for any help.

G-Man · Post by **G-Man** » Tue Jun 09, 2015 11:47 am

Mike

The shield on the RH bearing goes on the inside (crank side) but check the oil feed as the bike may have been equipped with a roller bearing originally and the ball race blocks off the feed......

This is an early case that was designed for the shielded ball race with the oil hole feeding to the outside - between the bearing and the seal.

And this is a later case with an oil feed designed to lubricate a roller bearing with a central oil hole.....

Here is a 'universal' case I found, with both types of lube hole.

Honda listed the early ball race as a 'fix' for later cranks with damaged roller tracks but I've never seen a service bulletin that says the mod blocked off the oil feed.

You can draw your own conclusions......

G

SMBH · Post by **SMBH** » Tue Jun 09, 2015 2:10 pm

Here a pic of my case and bearing

Here is a pic of the bearing on the other side left side it seams it was the wrong bearing I understand it should be 6306 the one in the pic is 722901B It is the same size as 6306 with a hole for the knock pin but the hole may have been wrong as the bearing was moving in and out.

G-Man · Post by **G-Man** » Tue Jun 09, 2015 2:25 pm

The bearing should be a tight fit in the case. Does it measure 77 mm diameter?

If it fits shaft an crankcase it should be fine.

G

SMBH · Post by **SMBH** » Tue Jun 09, 2015 2:43 pm

Yes it is 77mm but it is worn a lot of side play I need a new correct 6306 so if any one out there has a new one to sell part number 91001-259-010 please PM me let me know.

Thanks for your time Graham I have sent you a PM.

G-Man · Post by **G-Man** » Tue Jun 09, 2015 2:54 pm

Mike

You need to look for

91002-874-003

91001-259-020

91001-369-000

91001-259-010 is a 75 mm diameter bearing

G

SMBH · Post by **SMBH** » Tue Jun 09, 2015 3:01 pm

This I thought was for my 1964 CB77 engine number 102472

http://www.cmsnl.com/honda-cb77-general ... XdFf0adVaQ