I traded a couple of my vehicles for a 81' Chevrolet with a "supposed" rebuilt 350 motor in it.

I got the truck and it sounds great, motor sounds great, everything on it is solid but I noticed one leak that turned out to be the power steering pump.

I checked the power steering pump and noticed that one of the tubes coming out the back was broken short, so I got a replacement pump and began pulling the old one off to replace it. When I went to pull the belt off, I reached around the crankshaft pulley and noticed that I could actually move the pulley from side to side a little, and that I could turn the pulley over a small bit extremely easily and then it feels like it catches the crankshaft and wont turn anymore.

When the truck is on, it sounds great, I never thought to look at the pulley when it was running but my guess is that it moves around a little when running as well.

I havent had a chance to get back under there to further examine the issue because it was getting late when I first noticed the issue. I won't be back to the shop until a little later today, so I figured maybe somebody could give me some pointers as to what I should look for and what may cause this.

In my opinion it feels as if the harmonic balancer may not be pressed on all the way, because of the side to side movement; but in that case, why would it freely rotate a little? when i rotate it, i know it is not the whole shaft moving because it spins to easily


if you have any idea what this may be, please give me a little info here. I have replaced these before on different trucks, so once i get under there i will be able to better point out whats going on

 

Its not uncommon for the outer ring of a harmonic balancer to come loose. If this is the problem a simple replacement is the cure. If the balancer is loose on the shaft that is another problem. Try a new/good balancer and key and if it is loose the shaft is worn. Then you either replace the shaft or get out the welder.