787 rebuild counterbalance noise?

[Black67tb]

Hello. I am currently putting my motor together with a new crankshaft. I had the counterbalance redone. New bearings and seals. Also had the shaft checked to straightness. I have both shafts installed in the case as you see. When l turn the crank using the connecting rods and the PTO end of the crankshaft is rotating counterclockwise there is some kind of clicking or light tapping noise. But if l reverse the rotation , it sounds good.
Any comments would be greatly appreciated.

 

[mikidymac]

I would pull the balancer and crank and spin each bearing by hand to make sure they are all quiet and smooth. No new bearing should be making any clicking sounds.

 

[Black67tb]

I would pull the balancer and crank and spin each bearing by hand to make sure they are all quiet and smooth. No new bearing should be making any clicking sounds.

I have tried rotating the bearings on both shafts. They don't feel bad and sound good. When l remove the balance shaft from the case, and l rotate the crank using the connecting rods, the crank is turning quiet both directions. Why does this happen in only one direction? Could the old counterbalance gear meshing with the new crank gear be making this noise?

 

[Black67tb]

I would pull the balancer and crank and spin each bearing by hand to make sure they are all quiet and smooth. No new bearing should be making any clicking sounds.

I think l see the problem. The used balance shaft l purchased has 3 distorted teeth. Should have looked more closely when i bought it. I marked the teeth and when l rotate the crank, and they mesh with the new crank gear , and l could hear the clacking noise. This balance shaft had new bearings and seals installed. Now do l use it, hoping it will get better or do l need to replace. I don't know what it will sound at 1500 or 2,000 rpm.

 

[Notoriousscottyb]

Take a mill file to the bad teeth and get them back in shape. If you take your time and match them to the others it should come out perfect.

 

[Black67tb]

Yes. I think l will try your idea. May save me from getting another gear and bearing pressed on.

 

[Poormanracing]

Yup file the teeth be fine.do you have new crank bearings also or using the old ones?check the roller bearing cages on crank and make sure they still together

 

[Black67tb]

Yup file the teeth be fine.do you have new crank bearings also or using the old ones?check the roller bearing cages on crank and make sure they still together

Yes, everything is new but the balance shaft. Balance shaft has new bearings and seals, but old gear.

 

[etemplet]

I think l see the problem. The used balance shaft l purchased has 3 distorted teeth. Should have looked more closely when i bought it. I marked the teeth and when l rotate the crank, and they mesh with the new crank gear , and l could hear the clacking noise. This balance shaft had new bearings and seals installed. Now do l use it, hoping it will get better or do l need to replace. I don't know what it will sound at 1500 or 2,000 rpm.

I was going to tell you to check the teeth. Good Job !! .. Yes when it makes noise in one direction and not the other there is a good possiblity it is the gear. It meshes good on one side of the tooth but not the other. You can file the gear teeth but be careful not to take too much and make sure it is uniform. Cover the bearings so you don't get metal in them. Good Luck!!

 

[Black67tb]

Thanks for the feedback

 

[etemplet]

Thanks for the feedback

I'm thinking they might have damged the teeth while replacing the bearings. That is easy to do. Make sure the gears runs true when you spin it. In other words... not be bent. Good Luck !