I have a 69 307 without a hole and bolt in the crank. What is right way to install a new harmonic balancer?

A friend of mine has a 62 vett with a 327 and has the same problem. His had a shallow hole but no threads and he drilled and tapped so he could put the balancer back on after he had it rebuilt. This car is a 30,000 mile car so pulling the engine wasn't an option for him. I know he made a jig to go in the balancer hole to keep the bit straight.

Im guessing the O.P. meant 327 not 307?

I have used, on many , many occasions a piece of 2X4 and a hefty hammer. When the balancer bottoms against the lower timing gear the sound of the hammer blow will change significantly as will the feel of the whole operation. Thats when you quit hitting the 2X4.

There are many guys on this site who will be horrified by this method however back in the 50's and 60's that was the accepted method and it rarely, if ever, caused any harm. Back then none of the Chevrolet crankshaft snouts had a hole much less a threaded hole.

You will hear about how it will mess up your thrust bearing. That is so much bull. The thrust bearing goes through vastly more beatings everytime you run your engine than a few hammer blows through a 2X4 will ever give it.

Everytime your transmission shifts your thrust bearing gets a whack. Thats why its called a thrust bearing. Every time you step on the brakes or throttle your thrust bearing also gets a whack. Its no shrinking violet.

Those few beginning whacks don't do spit for harm.

There is a tool that is very inexpensive. Jegs selles them and Called an installer that is used to pull it on and doesn't hurt the engine. Does it very easly and right and doesn't take time at all and you know you haven't damaged anything. JimB Ps Yes we used to beat them on for years before we got techanical.

If the crank is not drilled, the balancer is a press fit. The 350 in my 86 Cutlass has the same setup. I pressed it on with a chunk of 4x4 and a hammer.

Oh no Charbilly, now you did it. Soon there will be 100 posts saying A friend of this guys uncle that once owned a body shop after he owned a pressure washing business said it will cause catastrophic damage to all main, rod and cam bearings as well as the seals LOL.
Merry Christmas.

I have used, on many , many occasions a piece of 2X4 and a hefty hammer. When the balancer bottoms against the lower timing gear the sound of the hammer blow will change significantly as will the feel of the whole operation. Thats when you quit hitting the 2X4.

There are many guys on this site who will be horrified by this method however back in the 50's and 60's that was the accepted method and it rarely, if ever, caused any harm. Back then none of the Chevrolet crankshaft snouts had a hole much less a threaded hole.

You will hear about how it will mess up your thrust bearing. That is so much bull. The thrust bearing goes through vastly more beatings everytime you run your engine than a few hammer blows through a 2X4 will ever give it.

Everytime your transmission shifts your thrust bearing gets a whack. Thats why its called a thrust bearing. Every time you step on the brakes or throttle your thrust bearing also gets a whack. Its no shrinking violet.

Those few beginning whacks don't do spit for harm.

It's a precission job to put a balancer on an engine. "What could be more precise than a big heavy hammer?!" (quote form Overhaulin' episode)
Done many, many times myself. Sometimes ya' gotta go for the B.F.H., or "All purpose tool" as the case may be. LOL:D

There is a tool that is very inexpensive. Jegs selles them and Called an installer that is used to pull it on and doesn't hurt the engine. Does it very easly and right and doesn't take time at all and you know you haven't damaged anything. JimB Ps Yes we used to beat them on for years before we got techanical.

How does the tool work on the above mentioned crank with no hole?

I've always put them on the same way as charbilly myself.

I had a 307 in a 68 without the bolt hole. As I recall, I removed the fan shroud for accessability, jacked up the front of the car, used a sharp drill bit with plenty of cutting oil and drilled and then tapped the hole. It was really a fairly easy job. Just have to drill the hole straight. It doesn't have to be aligned exactly to the mili-nano. Just fairly straight. All your using that hole for is to seat the balancer and then to install the bolt and large washer. Never had a problem.

Oh no Charbilly, now you did it. Soon there will be 100 posts saying A friend of this guys uncle that once owned a body shop after he owned a pressure washing business said it will cause catastrophic damage to all main, rod and cam bearings as well as the seals LOL.

Yeah this one I find as a shocker.....yet when I replaced the power steering pump the instructions said "DO NOT POUND ON WITH A HAMMER! PULLEY MUST BE PRESSED ON WITH APPROPRIATE TOOL"

Before that I was told my a mechanic if I were to have installed the pulley with a hammer it would've fudged up the pump seals and bearings. Glad I listened.

Junkyard, We are talking about the Harmonic Balancer, Not the PS pump pully.

Junkyard, We are talking about the Harmonic Balancer, Not the PS pump pully.

A horse of a different color :D

Junkyard, We are talking about the Harmonic Balancer, Not the PS pump pully.

YES I know that. :rolleyes:

I was just saying that's why I cringe at the thought of putting on a balancer by beating it on with a hammer as opposed to using the press on tool to install it.

Sorry.

I was replacing the timing chain in an old farm truck with a 327 that had the same problem. We were trying to heat the well venilated shop with an old wood stove. We did not have enough room to get a solid blow in with the hammer so the balancer was placed on the top of the wood stove. I put a very heavy coat of grease on the seal for protection. I did not know how hot the seal would have to be before it melted once it contacted the hot balancer but figured 250 was ok.

Sent my son to the house to get his mom's cooking thermometer and got the top of the stove to around 250. We wrapped the crank snout with an rag filled with snow. Got the balancer to what I figured was 250, jerked the rag off the crank, dried it off, slide the balancer on. I have used this method several times after if the engine is in the vehicle, not a drilled crank, or no room to swing the hammer.

It may not be scientific or the "correct" way but sometimes you do what you have to.

YES I know that. :rolleyes:

I was just saying that's why I cringe at the thought of putting on a balancer by beating it on with a hammer as opposed to using the press on tool to install it.

As long as you don't beat the balancer with the hammer and use a block of wood to absorb the kinetic energy from the blow of the hammer, it will be fine :)

Yeah this one I find as a shocker.....yet when I replaced the power steering pump the instructions said "DO NOT POUND ON WITH A HAMMER! PULLEY MUST BE PRESSED ON WITH APPROPRIATE TOOL"

Before that I was told my a mechanic if I were to have installed the pulley with a hammer it would've fudged up the pump seals and bearings. Glad I listened.


Dawg, take apart a power steering pump sometime and get a good look at the innards. You'll immediately see why you don't simply beat on the end of the pump shaft. There are breakable parts inside, unlike the crankshaft of an engine. "Breakable" is a relative thing. A crankshaft is NOT a delicate precision instrument. A power steering pump vane isn't either, however it IS made out of something moulded like phenolic resin and it will break if abused.

Further it has been stated in Team Chevelle that installing harmonic balancers with a hammer and a block of wood can some how hurt the thrust bearing. Thats is BS. As I said earlier the thrust bearing see's way more abuse in the running engine than it will ever see by installing a balancer with a few whacks of hammer against a block of wood.

There was a thread a few weeks back where I discussed how you could install a PS pump pulley. In that thread I advised removing the outer sheetmetal of the pump such that you could access the OTHER end of the pump shaft and support it properly.

Having done that it would be perfectly fine to pound the pump pulley onto the shaft as long as you had taken measurements before hand so you could install the pulley to the correct depth for proper belt alignment.


Guys there are lots of things that you can mess up while assembling an engine. Most foulups come from assembling them wrong not from over muscling them. A little common sense while hitting things with a hammer is clearly in order. Note that I never said "sledge Hammer". In my tool box is a hammer called a "Striking Hammer". It is made to do things like install harmonic dampners. I have attached what I call a "striking Hammer". In the thumbnail its called a "Club Hammer". Different name....same hammer.

It delivers a heavy blow while traveling a short arc at a relatively slow speed. Its strictly a one hand hammer and works well in close places. It also works well when struck with the side surface.

You guys can go back and fourth on what is going to work the best but the real issue is....Do you have the clearance on the front of the engine to use a hammer and a piece of wood if the engine is still in the car? Not unless you are going to go through the extra work of draining the cooling system and removing the radiator, which still wont allow you to make a good swing with a hammer. Not with the grill there either.

Either way will work just fine. A hammer works if the engine is out of the car. Otherwise dont waist your time and get the proper installation tool.

Sorry. My thought of drilling and putting it on in a rather simple way just was the way I have been taught and never thought of Banging it on with a Hammer. I have alway been told for over 45 years and even longer never hit something that wasn't designed to be beat with a hammer. I just believe that a engine is a kinda of an expensive item to start hitting with a hammer. Drill the hole and use the correct tool.Jim B

I have to agree 100% with those who say to use a piece of wood and a big hammer.
Without question, it is much better to pull the balancer on with the proper tool. But the early engines that didn't have the threaded hole had to have the balancer driven on by a hammer. I have never had a problem and I've never known anyone else who had a problem by driving on the balancer. If your crank has the hole, use the proper tool to pull it on. If you can drill and tap a hole, that's also the best thing to do.
But, if your crank doesn't have the hole, and you can't or don't want to drill/tap a hole, use the hammer and block of wood.

Well , It sounds like DZAuto has common sence and can do what ever comes his way. Nice answer with out question. I however would drill the hole if I had room to swing a hammer. I have ruin too many things in my life to start swinging a hammer again. The funny thing is. I have tried many times to do some thing to fit and a friend would come in and hit it with a hammer and it would be done and saved me hours of time. Jimb

If one doesn't have room to use the hammer/wood method how's one going to drill a STRAIGHT hole in the end of the crank and then tap it?
I've never drilled a hole in the snout of a crank - how tough is the material to drill and tap? Heaven forbid if the hole isn't straight and true and then trying to use a correct installation tool to press the balancer on; wouldn't that pull the balancer on crooked if the hole isn't straight?

Granted a BFH and a block of wood may not be the preferred method, but it's been used for years - as long as one doesn't act like a 800 lbs gorilla and go crazy. :D

Actually, a crank shaft is only hardened to a certain depth. Past that, it's just cast iron. Drill the first, I think it's about .060, and it gets much easier. That's why they say not to turn a crank past .020. It gets soft and weak.

If one doesn't have room to use the hammer/wood method how's one going to drill a STRAIGHT hole in the end of the crank and then tap it?
I've never drilled a hole in the snout of a crank - how tough is the material to drill and tap? Heaven forbid if the hole isn't straight and true and then trying to use a correct installation tool to press the balancer on; wouldn't that pull the balancer on crooked if the hole isn't straight?

Granted a BFH and a block of wood may not be the preferred method, but it's been used for years - as long as one doesn't act like a 800 lbs gorilla and go crazy. :D

Actually Dale. There are 90 deg. angle drills out there that do allow to work in such areas. But like you said, the hole still has to be drilled in straight regardless.

I have a friend with a 69 Camaro with a 307 who was replacing his water pump this summer and when he took the belts off, the damper fell off of the end of the crankshaft on the floor. If it had come off while running he could have have lots of problems. He drilled the crank and put a new balancer on with a bolt.

When I put the 327 back in my Chevelle this summer I went ahead and drilled my crank and put the bolt in as I didn't want to take an chances.:)