1965 Cadillac hub/harmonic balancer removal from crank shaft

[Scot Minesinger]

Working on a timing chain replacement for 1965 Cadillac.  I have removed several hub/harmonic balancers from crank shaft on 472 engines.  The procedure is basically the same for a 429, and both have the 9/16" fine thread in crank shaft.

The first attempt sheared off the edges of the 5/16" bolt head.  Now I have real good washers on it, and I feel like I'm going to break something.  I'm using a two foot cheater on wrench, and probably just stretching the 5/16" bolts right now.

Here is a picture.

Basically I'm using a home made 9/16" fine thread bolt threaded into crankshaft.  Then I have a plate with a nut between it and the end of the crank shaft.  Two 5/16" bolts threaded into hub/harmonic balancer thru plate.  Then I have a wrench on the end of the 9/16" bolt head so it cannot turn.  Next I just back the nut towards front of car which force plate and hub of the crank.  Torque I'm using is like 120 ft-lbs, and on last five I did maybe 50 ft-lbs was enough.

Could it be seized rusted on?  I feel like worse thing that happens if I use a lot of muscle is the 5/16" bolts fail?  I'm leaving it in tension overnight.  Gave it few very slight taps to no avail.

Thoughts?

[The Tassie Devil(le)]

Isn't the pulley held on by 4 bolts?

I wouldn't be relying on just the two bolts.   I would be using all I could.   I realise that it will make it impossible to use a spanner to turn the nut, but I would be pressing on the end of the crank with a large washer, and using the big bolt as a pusher, not a winder-out-on thread.

Plus, I would be applying a lot of pressure, then letting it stand, and hitting it a few times, and keeping the pressure on it.

Plus, I would be applying a bit of CRC or other liquid into the void, plus lubricant to the thread

Bruce.

[Scot Minesinger]

Bruce,

It is under pressure right now and will leave it that way all night.  I could get a closed ratchet wrench and make four bolts work, my set only goes to 3/4", so have to pick up a 7/8" at auto parts store tomorrow.  Have done four 472's and two 500's and never had this much trouble.

The 9/16" threaded rod in picture is treaded into crank about an inch, so same as using a big washer no issue there. 

Will keep at it.

[The Tassie Devil(le)]

What I do is to screw a short 9/16" bolt into the snout, and use the head of the bolt as the pressing spot.   This saves any possible damage to the thread within the crank.

Using the four press flange bolts really allows me to use extreme pressure on the extracting bolt.

Bruce.

[Scot Minesinger]

Got it.  Thanks Bruce for your ideas.

The overnight tension and some love taps on wrench this morning broke it free.  That must have more of an interference fit than the 472/500 cranks, as that was way tougher.  I guess the factory removal method will not damage the crank, so you can be fairly forceful, worst case a 5/16" bolt breaks.