The Stovebolt Site Forums The Shop Area Engine Shop 235 loose harmonic balancer help

I found a great running 235 that does not smoke to replace the tired old 235 in my 1959 1/2 ton. But the new motor has a very loose harmonic balancer (like really loose I can easily move it with my hands)

How much of a can of worms could I be getting into with the loose harmonic balancer? How hard are they to replace and are they typically OK after replacement or are they prone to getting loose again after it happens a first time?

Thanks for any help

Dave

It depends on whether the crankshaft snout is worn or not. Sometimes the balancer hub cracks at the keyway and loses its press fit. That's a pretty quick fix, just install another balancer. If that one has been running with a loose balancer for a while, it can have a worn crankshaft snout that won't let a new balancer press on tight enough to stay put, or the keyway in the crankshaft can be worn to the point that the balancer will move slightly from the torsional strains of running. A worn snout diameter and/or a damaged keyway will require the crankshaft to be removed and welded, then re-machined to the correct dimensions. I have done a temporary repair by brazing the key to the crankshaft, but it's not a good long-term fix. I'd suggest pulling the balancer and doing a thorough inspection, including taking measurements with a micrometer or a dial caliper to find out where the worn areas are, before committing to buy the engine.

I have a drill and tap guide available for use by members of the forum to install a center bolt in the crank snout. I get a small deposit plus a shipping/handling charge but it's basically a break-even situation. It won't fix worn keyways, etc., but it will allow the balancer to be bolted on solidly.
Jerry

Thanks for the help. I am going to pass on the 235 and keep looking for a better one.

Thanks

Dave

I had the loose harmonic balancer problem on a 235 in my truck, when I took the front end off to change it , out of the 5 or 6 that I had, only one went on tight. On my new motor, I had the crank drilled at the machine shop.