Some time ago I replaced the harmonic balancer because the crank pulley wobbled. The balancer was cracked. I puchased a good used balancer and all seemed fine for a while. This is no longer the case. I finally took a closer look at everything. The bolt itself is compromised. There are two chips in the threads and in general it looks like it was cross threaded. I checked the balancer and believe it is now compromized, but not cracked like the previous one but I assume the ID is our of round because it does have slop when pressed onto the crank. As far as I can tell the crank threads are fine, but I think the best course of action is to buy a new balancer, not rebuild this one and buy a new balance bolt. I would prefer a longer bolt to get more "bite" into some fresh thread. Who sells longer harmonic balancer bolts - is there even such a thing for these motors? Thanks, -Chad
http://v8buick.com/index.php?threads/romac-balancer-bolt-size.282828/#post-2332420 Longer bolt for the Romac balancer, 3/4-16 X 2" long. 10 of them on E bay, https://www.ebay.com/itm/Qty-10-3-4...:USPSPriorityMailSmallFlatRateBox!11358!US!-1
Not an area to skimp on with a Chinese hardware store bolt......stock Buick balancers are not a press fit so they rely on the bolt more and 200 lb/ft of torque...than a lot of other motors. Does make it easy to remove...once you manage to get the bolt off....
OK, I missed something I order the seals from Autoplicity per this thread (http://v8buick.com/index.php?thread...k-seal-timing-cover-seal.344394/#post-2919269). BUT I did not see that I need to remove the front cover to install or modify the front cover to have this seal install. Is this an unwriten tribal knowledge thing?
Stock timing covers need to be removed to install the new seal as they press in from the back. TA Timing covers have seals that are installed from the front.
Welp. Got it all together with a longer bolt. Lasted about 5 minutes before the wobble started again. Hmm. The investigation continues. Will double check the balancer and maybe replace.
That is my fear, I dont want to pull the engine. I've only looked at the front end of the crank, I did not measure with a micrometer. Visually there was no obvious distortion however, I am searching for another crank and thankfully my dad has a spare I could use in the mean time. I have another stock replacement balancer ordered. If this gets too $$$ that 455 just might be benched by an LS. Those LS are tempting for the price.
New used balancer, new longer bolt, balancer still wobbles a bit. What has helped is cutting a flat washer to fit on the inside of the balancer since the balancer does not tighten flat against the edge of the crank snoot, and still use the concave thick balancer washer. I also added a bronze sleeve to keep all washers centered. I don't have another 455 near by to compare, but watching the GN crank pulley run smooth and straight and knowing that my 455 balancer can run smoth and straight during initial install. I still find the wobble a concern.
You have a crank issue, I'd pull the cover and check it with a caliper ,..and run out you'll need to pull the plugs to spin it well enough