I pulled my 272 out of my 57 truck to fix the rear seal very small leak and paint the engine. I pulled the harmonic balancer and notice that there is play in the crankshaft front to back. I'm not an experienced engine guy, so should there be any play and if so how much? What would be causing the problem a bearing?

 

The crank shaft end play new should be .002 to .006 but the wear limit is .010 this can be checked with a dial indicator. The main thrust bearing could be worn.

 

Are you SURE it is the crank and not the balancer that is moving?

The balancer is 2 sections seperated by rubber. That rubber is well known to break down and cause the 2 steel pieces to move independently. This is also a major cause of Y block timing problems.

 

The balancer is off the shaft and I can just pull shaft in and out about a 1/4 inch

 

one side or both sides are gone of your thrust bearing.drop your base you should see the pieces in the base.its your center main.

 

When I take this apart what other things should I look for or does the thrust bearing have a tendency to fail in these motors. Where is a good place to shop for this bearing?