Engine Vibration

6

64TA-Skylark

Newbie
Hi Teambuick -

I'm new to the forum and Buicks. I just bought a beautiful 1964 Skylark about 4 weeks ago. When I bought it there was an extremely bad (literally shakes the car from side to side) vibration when you rev the engine, almost as if the engine or something rotating is out of balance. It could be the engine - but I did do a compression check (dry) and everything is about 175+. I did see a bit of oil on a couple of the plugs, which I suspect is from the valve stem seals, although I can't be sure at this point. I know the Buicks are externally balanced motors (I think all of them are) and feel that this probably is something external that has become loose, gone bad, or was not put back on correctly. I know the previous owner had done some transmission work and then he seemed to believe this vibration (near earthquake) happened thereafter. Here is some info on the engine trans:

1970 Stage 1 455 bored 40 over and built by TA
Unknown age BOP turbo 400, that was rebuilt about 1 year ago, vibration thereafter. Torque converter not touched.

Any ideas on where to start?
Thanks for any help.
Raymond
 
You could begin by isolating the problem to either the engine or the transmission. Unbolt the flexplate from the converter and push the converter back. Now start the engine. Do you still get the vibration?
 
raycow said:
You could begin by isolating the problem to either the engine or the transmission. Unbolt the flexplate from the converter and push the converter back. Now start the engine. Do you still get the vibration?
Click to expand...

OK - that is where I was going to start but was looking for something easier since I'll be doing this in my home garage, car on jackstands, and of course me on my back under the car. I'll post back what I come back with. Thanks for the reply.
 
Well, the initial part doesn't really involve all that much. There is just the bellhousing bottom cover and then three bolts holding the flexplate to the converter. The hardest part is probably turning the flexplate by hand so you can get to all of the bolts.

Of course once you do narrow down the problem area, you will have to separate the transmission from the engine, and that's where the serious work begins.

Ray
 
Problem Solved - Harmonic Balancer

I found the vibration. The original harmonic balancer had nearly self destructed. When I took off the belt pulley to get the balancer off, I noticed a lot of rubber droppings behind the pulley, next the balancer bolt. When I removed the balancer - which is really a two piece assembly - held together by rubber cushion, half the cushion was gone. The outer portion of the balancer had also moved (spun) past where it was originally adhered together - about 45 degrees. The TDC 0 mark on the out portion of the balancer is supposed to be aligned with the keyway on the inner hub. I'm still in shock that it was still holding together. I guess this is why they make SFI balancers.
 
Consider yourself fortunate that you discovered the bad balancer before it separated while turning at high RPM.

Ray
 
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