Looking at the pics in Floridamale's link.... I see what you mean. Should I be able to see this without removing the pulley?

 

Trust me, the outer rings CAN and DO turn on the inner ring.
Not uncommon at all.

 

Yes. This is what a slipped balancer looks like:
First pic shows a good balancer. Blue and Red lines line up. Outer ring is flush with center mounting hub.
Also note the free space between the back of the balancer and front timing cover.
Second pic shows slippage with green arrows. Outer ring and hub are no longer flush. Balancer has backed up
all the way against the timing cover.
On a good balancer, the edge of the timing tab teeth are about half way over the balancer.
This can be used as a convenient visual reference as well.



Sound like your balancer might have slipped 180 degrees.

Rotate the engine by the crank bolt with a socket. Smear white toothpaste or some white pipe sealant into the timing mark cutout of the balancer once you find it. Wipe the excess by hand and now only the timing mark should be perfectly white, and try timing again. If you still can't see it, loosen the distributor clamp bolt and rotate the dist both ways while you flash the timing light. If the mark still does not come into view, you probably have balancer slippage. You can tell that by just looking to see if the outer balancer ring (the one with the timing mark cutout) is flush with it's center mounting hub. It should be flush.

Don't put off replacing a slipped balancer. It will slide back wards and start to grind against the timing cover. Leave it like that long enough, and it will eat a hole through it, cause an oil leak, and toss metal shaving into your motor oil.









This is the EST plug you disconnect prior to setting timing. Will set a trouble code. To clear, disconnect the battery for a few minutes and reconnect:



To replace, rent the balancer puller and installer from Autozone.
It's basically free, you leave a deposit and get it back
once you return the tools undamaged. The puller looks like a steering wheel puller and works the same way. This is the installer pictured below.



The upper steering rack line needs to be disconnected and moved to the side to make room for both tools. Turn the installer shaft with a deep socket slid over the end instead of an open end wrench from the side. A deep socket acts as a cup, shielding the threads from scraping/damaging against the steering rack as you turn. Use a crowfoot with extensions to easily disconnect this fitting from above. This fitting DOES NOT have an o-ring in there. It's the opposite ends of the line that do.

 

I defer to the expert...myself being a hobbiest and enthusiast and not a professional in the trade there are no doubt others who have seen more slipped HB's than me. The slip backwards toward the TC is really evidence enough that the HB needs replaced, and it will be very difficult to strobe the timing mark in this condition as it will be covered by the timing tab.

 

Thank you all so much for your help. I really appreciate all your pics 86SPACER, it was very helpful. I now know exactly what you mean. I will check and keep you all informed. Thanks again.

 

Have been helping (via phone) a buddy chase a weird timing issue on one of his marine 454's.
Like a lot of people he came up with all sorts of off the wall causes and was very reluctant to actually check for a spun balancer.

Guess what the problem turned out to be?

Another spun balancer ring.

 

I can't offer a whole lot of insight on Dorman except to tell you that I replaced the original HB with a Dorman (bought through NAPA) 3 years ago, It seems to be working fine, and holding together but I have know why of knowing whether it will last as long as the original one did (i.e. 22 years!)

 

I went with Dorman from Autozone, $50. Not a single issue with mine.
They have the puller and installer there too that you can rent.