Harmonic Balancer Lip

[67 GTX]

Hey Guys,

I got the balancer off of my 440 the other day in order to try and find exactly where my oil leak was coming from. Looking from right to left in the photo, the second black ring is deep enough that it catches my finger nail. I think it's safe to say that oil can get around that right?

The rubber seal seems fine, so I order a repair sleeve. Apparently from what I've gathered, this is a common issue.

 

[miller]

I've had them like that, plenty of times, just seating in. Balancer rides with the crank, including the fore/aft endplay movement. With much of a groove cut it, that's when they leak.
Doesn't look that deep, to me, and the seal is probably fitting tight enough. I usually rub on the shaft with 400 grit wet, smooth the shaft, until the groove is gone. But, that's your call. It's worked for me, plenty of times.
Yep, then, if it doesn't seal...a repair sleeve. Shaft is stock diameter, and a sleeve would go on tight. Taking the diameter down, only a little, would help.

 

[Yatzee]

Hey Guys,

I got the balancer off of my 440 the other day in order to try and find exactly where my oil leak was coming from. Looking from right to left in the photo, the second black ring is deep enough that it catches my finger nail. I think it's safe to say that oil can get around that right?

The rubber seal seems fine, so I order a repair sleeve. Apparently from what I've gathered, this is a common issue.

View attachment 527751

You can pretty much polish that out using crocus paper or wet dry starting with 400 and finishing with 800. Replace the seal with a "double-lip" seal this time. It actually wasn't leaking as indicated by the section after the seal.

 

[Cranky]

Was the back of the balancer wet with oil when you pulled it off?

 

[67 GTX]

Was the back of the balancer wet with oil when you pulled it off?

You can pretty much polish that out using crocus paper or wet dry starting with 400 and finishing with 800. Replace the seal with a "double-lip" seal this time. It actually wasn't leaking as indicated by the section after the seal.

It really wasn't that wet. There was a slight build up of oil sitting on the bottom of the timing cover/oil pan right behind the balancer. But isn't that a pretty weird thing to start leaking?

Is the "double-lip" seal one that goes in the timing cover? Or is that a type of repair sleeve?

 

[67 GTX]

I've had them like that, plenty of times, just seating in. Balancer rides with the crank, including the fore/aft endplay movement. With much of a groove cut it, that's when they leak.
Doesn't look that deep, to me, and the seal is probably fitting tight enough. I usually rub on the shaft with 400 grit wet, smooth the shaft, until the groove is gone. But, that's your call. It's worked for me, plenty of times.
Yep, then, if it doesn't seal...a repair sleeve. Shaft is stock diameter, and a sleeve would go on tight. Taking the diameter down, only a little, would help.

The balancer has been touching that seal for a few years now, and about 3000 or so miles. I changed the seal a few years ago, but don't remember if there was much of a lip of the balancer back when I did it.

I like your idea on smoothing the shaft out a bit. I have heard that the sleeve makes it a very tight fit upon installing the balancer back in.
Would having too tight a fit make the seal possibly crack or rip?

 

[Cranky]

Yes, the sleeve makes the seal tight....tighter than I like. Your balancer doesn't look bad at all and polishing should take care of it. I have an engine lathe so it's easy for me to polish one....

 

[Garys1969RR]

I think if the groove is deep enough to catch your fingernail, a polish probably won't get it out. Crocus cloth is good for cleaning up any slight imperfections on there, before you install the sleeve. Put the balancer in the freezer all night, to make it contract slightly, and warm up the repair sleeve with a hair dryer before you put it on. With the sleeve expanded, and the balancer contracted, it should slide on there more easily. I've used this trick many times, when there is a slight interference fit, and it makes the job way easier. It works! You can also throw the new seal into the freezer for a few hours, to make it fit into the front cover more easily.

 

[67 GTX]

Yes, the sleeve makes the seal tight....tighter than I like. Your balancer doesn't look bad at all and polishing should take care of it. I have an engine lathe so it's easy for me to polish one....

Then do you think my leak is coming from somewhere else?

I think if the groove is deep enough to catch your fingernail, a polish probably won't get it out. Crocus cloth is good for cleaning up any slight imperfections on there, before you install the sleeve. Put the balancer in the freezer all night, to make it contract slightly, and warm up the repair sleeve with a hair dryer before you put it on. With the sleeve expanded, and the balancer contracted, it should slide on there more easily. I've used this trick many times, when there is a slight interference fit, and it makes the job way easier. It works! You can also throw the new seal into the freezer for a few hours, to make it fit into the front cover more easily.

The groove is definitely deep enough to catch my fingernail, and I don't have much of a nail as it is. All great ideas! I think I'll take those suggestions. Anything to make the job easier.

 

[PRND21]

It really wasn't that wet. There was a slight build up of oil sitting on the bottom of the timing cover/oil pan right behind the balancer. But isn't that a pretty weird thing to start leaking?

Is the "double-lip" seal one that goes in the timing cover? Or is that a type of repair sleeve?

Was any sealant used on the outside of the seal before it was installed in the timing cover? I’ve seen seals leak around the outside steel part of the seal many times.

 

[miller]

Is the "double-lip" seal one that goes in the timing cover?

It's the seal itself. Some different than others. They can have either just one actual sealing 'lip', or two, one keeping crap out...other keeping oil in.