Harmonic Balancer installation

[Donald Rivard]

I am completing the assembly of a 1959 348. I installed the harmonic balancer as far as it would go today but I unfortunately didn't notice how far on the crank shaft it was supposed to go. Can anyone tell me what the measurement from the end of the crankshaft to the face of the balancer should be when it is fully seated. Either that the the measurement from the timing chain cover to the front of the balancer will work. Thanks
Don

 

[tripower]

I believe it should but up to the timing gear.

 

[Shake-N-Bake]

Dan is correct. Suck that thing up all the way until it contacts the timing chain crank sprocket.

 

[W-motorhead]

For the proper installation of a harmonic balancer, see the following, very informative YouTube video from Boxwrench:

If you don't have the balancer inserted fully, you will be sad to discover that your belt pulleys don't align properly during final engine assembly. You can monitor this during the balancer installation by loosely attaching your crank pulley and belt tension pulley and make sure the belt grooves are aligned. It takes a huge amount of force to fully seat the harmonic balancer onto the crankshaft nose. Boxwrench sells a strong puller/remover tool for this purpose.

Dan Fults

 

[tripower]

That tool used in the video works great if your crankshaft is drilled. Stock 348/409 cranks aren't. The second tool they showed at the end of the video is the one that would be used for a non drilled crank.

 

[EZ Cool]

That tool used in the video works great if your crankshaft is drilled. Stock 348/409 cranks aren't. The second tool they showed at the end of the video is the one that would be used for a non drilled crank.

I have to disagree, the second tool pictured is a combo tool that is used to pull the balancer as well as replace it if the crank is drilled. I have never seen a tool made that will press a balancer onto a non drilled crank short of a BFH.

 

[tripower]

I have to disagree, the second tool pictured is a combo tool that is used to pull the balancer as well as replace it if the crank is drilled. I have never seen a tool made that will press a balancer onto a non drilled crank short of a BFH.

You are correct I should have clarified that. The service manual even shows the installation with a BFH...

 

[Wrencher]

I don't take any chances with early chevy engines. Once I have completed the assembly of the short block, I set it on the flywheel (if it's a manual trans car) or on a block of wood if it's an Automatic and drive the balancer on with Medium sledge hammer cushioned with a 2x8. If you don't set it on the back of the crank, you run the risk of damaging the thrust main bearing surface of the #5 bearing. I admit I have often just driven them on without ill effects, but I support my good engines. Never fails to seat the balancer.

 

[64ss409]

I have the machine shop drill the crank, then I can pull the balancer on. I just had that done on a 62 327.

 

[Shake-N-Bake]

That tool used in the video works great if your crankshaft is drilled. Stock 348/409 cranks aren't. .....

Are you sure about that? Last week I pulled the engine from our car so I could change all the seals and gaskets. The crank appears to be drilled and tapped for a fine thread bolt. We have owned the car since new and this is the first time the engine has ever been out of the car. ???

 

[303Radar]

What would the problem be using a large press to install the harmonic balancer before installing the crank?

 

[Don Jacks]

303 Radar,There wouldnt be any problem with that method as long as the engine is out of the car,just more work. As to the cranks beibg drilled,I know that my 59 348 crank is not drilled,cant say about my 65 340 horse 409 crank.If it isnt,it WILL be before being installed.I've had a balancer come off at rpm,never again.It broke a new water pump,and caused me to have to spend money to have my new radiator repaired,not to mention having to "bum" a ride back to borrow a tow truck!

 

[tripower]

Are you sure about that? Last week I pulled the engine from our car so I could change all the seals and gaskets. The crank appears to be drilled and tapped for a fine thread bolt. We have owned the car since new and this is the first time the engine has ever been out of the car. ???

Is there a bolt in the end of the crank?

 

[yellow wagon]

Have the machine shop drill the end of the crank, problem solved

 

[Shake-N-Bake]

Is there a bolt in the end of the crank?

There was no bolt in the center. Just the three bolts that hold the pulley to the balancer. Everything was fairly caked up with grease (hence the reason why I pulled it out to reseal everything) and I started digging at the hole in the center of the crank. Once I cleaned it up, I noticed the hole was tapped for threads. I then asked my father if he remembers removing a center bolt and he said that he hasn't ever touched that area of the engine. He bought the car brand new in Feb '61 and his memory is pretty good so I am fairly sure there wasn't ever a bolt on the crank. The crank snout had orange paint on it that was covered with 50 years of road grime.

 

[Don Jacks]

Nice looking engine.If it were mine,it would get a bolt and washer there,just saying.

 

[Fathead Racing]

I been pounding 348 balancers on for seems like forever. I do back the crank with a big lead hammer. I like the guy who stands the engine on the crank and them hammers it on. It is a good idea to back the crank with some kind of dead blow hammer and use the same to whack that puppy on the crank. I never had issues. Sensing when it's on all the way takes some experience .

 

[Shake-N-Bake]

Nice looking engine.If it were mine,it would get a bolt and washer there,just saying.

Thanks. Agree on the bolt idea. I just need to figure out what the thread pitch is so I can source a new bolt. Any idea what torque value I should use?

 

[Fathead Racing]

I think it's 80 ft. Lbs.

 

[Shake-N-Bake]

I think it's 80 ft. Lbs.

Thank you.
I just remembered that we have another 348 complete engine in the shed that my father pulled from his buddy's car after he wrapped it around a telephone pole back in the mid 60's. I'll check and see if there is a crank bolt on that thing. (might get lucky...)