Primary shaft bearing

daves79x · Post by **daves79x** » Sun Aug 02, 2009 6:37 am

For those of you that saw and heard my silver '79 at Mid-Ohio, you know I was pretty sure the whine was the primary shaft bearing on the clutch side. I got the engine out and apart yesterday and that's exactly what it was. The bearing sounded like it had gravel in it instead of balls. It hadn't started shedding pieces yet, but would have soon. I've heard of 2 or 3 of these bearings failing. It may have to do with the alternator plates burning up and getting the shaft so hot that sludge builds up in the oil path inside. That may starve the far side bearing. The bearing nearest the alternator was fine.

Anyway, I just put a good spare shaft back in and buttoned it up. It's sitting on the bench for some paint touch-up before reinstallation. Looks like it will make someone a very nice rider.

Dave

ericfreeman · Post by **ericfreeman** » Sun Aug 02, 2009 11:47 am

I'm curious as to how many miles you have on the original bearing and if this is a common problem with CBX's. Thanks.

Eric

daves79x · Post by **daves79x** » Sun Aug 02, 2009 6:58 pm

I can't say it's a common problem at all. I've heard of 2 or 3 others. The bike only has 20,000 miles and one other '80 I know had the problem around that mileage also. I've got an 80,000 mile '80 that's never been apart and is fine. Wouldn't worry about it.

Dave

alimey4u2 · Post by **alimey4u2** » Mon Aug 03, 2009 5:09 am

This may connect with George's recent post of the alternator clutch oil restrictor button falling out. I would hazzard a guess, if this were the case, the oil flow to the primary shaft bearing would be compromised.