I rebuilt the top-end of my motor over this past winter break. Before I started the engine leaked no oil and ran smooth. Now that I have rebuilt the top half of the motor the harmonic balancer (stock old 8") wobbles when the engine is idling. The engine also leaks oil now, and guess where it is coming from. The crank seal in the timing chain cover.

Some notes on the rebuild. I reused the stock timing chain cover and even used the same seal that has always been with the motor. Also didn't change the balancer.

Are the oil leaks and wobbling balancer related?
Can balancers go bad?

I am going to tear into on Friday. What should I look for? How do I know if the balancer went bad.

Thanks
Brady

 

First off, if the balancer is wobbling, I woudlnt run it anymore. I would tend to think that this would be damaging to the bearings and other internal parts. I'm not familiar with older all oil pan gaskets, but is it rubber? If you didnt mess the gasket up, and it is installed correctly, using RTV sealant at the corners of the pan/block/timing cover, there should be no leaking.
As for the balancer, perhaps a dumb question, but did you draw it all the way on with the installer? Should be about 1/8" or so between balancer and timing cover.

One other note, are you sure its leaking oil at the bottom of the timing cover/pan? If you adjusted your valves with the engine running, the oil can run down the side of the block, and it may appear as if its originating in the location you described. Just something I'm throwing out there.

 

Yup, the balancer is in the correct position and it's properly torqued down. I am not 100% sure that it is wobbling (if it is that sounds very violent on the motor), but it looks like it might be a little bit....

 

by top end you mean heads right? the dampner never came off for that right? it would of had to of wobbled before you started the top end repairs. are you sure it's not a pulley running out and not the dampner.oil leak could be a valve cover or china wall seal.

 

Make sure your balancer is okay! The balancer on my brother's old blazer started wobbling and it turned out to be cracked where it slips on the crank. We ended up having to replace the crankshaft because the wobbling chewed up the end of the crank where the woodruff key goes. Changing the balancer is a lot cheaper and easier than replacing the crank. Also, a new seal for the crank where it comes through the timing chain cover is so cheap and easy to replace, you'd be crazy to re-use the old one. Also, it's a good idea to use a balancer installer tool to put a new one on. Hammering them on, even using a block of wood, can screw them up pretty good. You can get the tool fairly cheap through summit or jegs.

 

You can also borrow one from AutoZone for free.