Topic: Final Drive Shaft Seal Leak... Blown Bearing??

[bompxc]

The saga continues. After a top end and carb rebuild, its time to pull the engine again.  I had oil leaking down the kickstand and thought it was simply a blown final drive shaft seal.  After taking off the sprocket and pulling the oil seal which was indeed blown, I discovered the bearing right behind it was blown up.  The ball bearings were still in place and not falling out, however the bearing retainer that keeps them at equal intervals came out in pieces.  My concerns:

1. As I begin to prepare for splitting the cases, is there anything else to look out for and expect, or is it simply a case of replacing the bearing and sealing everything back up?

2.  In terms of a replacement bearing, as per Ebay, I'm assuming anything would work between 1973 and 1976? I have a 1974 CB750 K4.

Any help or advice would be appreciated!

[edwardmorris]

If you're splitting the cases, and if you really have a roller bearing blow up on you  I'd suggest taking the time, biting the bullet and replacing them all with better ones. These are all standard bearing except for the two grooved ones on the main shaft. They're standard size but the groove isn't wide enough on modern replacements, but a good machine/grinding shop can help with the groove widening (or DIY with a dremel??). See my K2 build thread in my sig, I recently changed all mine out with SKFs for precisely this fear (although I never dreamed of actually seeing/hearing it happen to anyone ).

[brandEn]

FYI you can split the cases and replace that bearing without taking the top end off. Not sure if you knew that. Hope this helps.