C2- 1966 327/300 Press On Harmonic Balancer

[Ronnie Robertson # 36786]

Yesterday, my harmonic balancer disloged itself from my crankshaft and after a lot of bangs, thumps and rumbles, I watched in the rearview mirror as it rolled gracefully down the street! I searched the archives and found lots of info about the press-on harmonic balancer. Most suggest holding the clutch in to prevent damage to the rear crankshaft seal when hammering the harmonic balancer into position. The problem is that my car is a powerglide! Can anyone suggest installation procedures or precautions when installing a new balancer.
Thanks

[Wayne W.]

Re: C2- 1966 327/300 Press On Harmonic Balancer

The new balancer will probably come off too. The shaft will probably be worn.

[Mike M.]

Re: C2- 1966 327/300 Press On Harmonic Balancer

you're not gonna like hearing this, but the engine needs disassembled. after its rebuilt, have the machine shiop drill and tap the front end of the crank so you'll be able to bolt the harm. bal. to the crank on reassembly.mike

[Jim T.]

Re: C2- 1966 327/300 Press On Harmonic Balancer

In 1968 I rebuilt my 64's 327 and installed a new GM balancer. The balancer came off, no damage, caught it early. Did not have time to do it myself, so took the car to Chev dealer garage. They put on a new balancer, saying the one I put on was not the right one. They did it with the engine in the car and later I drove the 64 from San Diego,CA to Glynco,GA and then to Dallas,TX and it stayed on. I don't know how the mechanic did it with the engine in the car.

[Mike McKown]

Re: C2- 1966 327/300 Press On Harmonic Balancer

You might check the nose of the crank before you tear it down. If you get lucky, your crank will have a drilled snout already. The standard 300 didn't come this way, but exceptions are made in assembly. You could also have a replacement crank.

I'm not too sure you couldn't fab some type of drill bushing and drill and tap it with the engine together.

Mike

[Ronnie Robertson # 36786]

Re: C2- Diameter of the Crank?

Thanks for the advice. Anyone know here can I find specifications for the diameter of the end of the crank? I thought I could measure the cramk to determine if it is worn, or if the old balancer is worn- or BOTH.

[Mike Cobine]

Re: C2- 1966 327/300 Press On Harmonic Balancer

It is easy if you have the right stuff. You bolt a bar across the crank and balancer with the front mount holes. Then you tighten a huge fine thread bolt in the center of the bar that presses the balancer on the shaft. Think of a harmonic balancer puller that is big enough to reach the front mount holes.

Mine was plate stainless about 1 inch thick that was bolted solid to two spacers between the bar and the block. Unfortunately, I don't know where it went in all the moves. I haven't used it since my '63 conv tossed the balancer 20 miles from home 27 years ago.

You need solid spacers from the block to the bar to prevent it from twisting back (up) when you tighten the big bolt since the front mount holes are not in line with the CL of the crankshaft. They have to be about 5 inches tall.

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Pressing the clutch is an old tale. You are pressing the springs on the clutch, not directly on the flywheel. Since few clutch geometries will ever let you press the spring to the limit, you can never exert full force on the flywheel and crank to prevent it from moving when the hammer hits.

Realistically, if the clutch could exert the same force as the hammer blows, then depressing the clutch on a normal trip to work would do more damage than hammering on the balancer.

[Mike Cobine]

Balancer Press URL

I forgot the HTML would wipe out the spaces in the message. Try the URL below.

http://www.geocities.com/MotorCity/Downs/3001/balpress.htm