The Stovebolt Site Forums The Shop Area Engine Shop Harmonic Balancer installation

I'm in the process of completing my 1955 235 engine rebuild and I need to reinstall the harmonic balancer. I have little trouble getting the balancer installed to within about a half inch of where it will seat and provide clearance to the fan blade. I've tried several lubricants and several different hammers, from big to small, and nothing seems to make a difference. I've searched the forums and have run across several articles that suggest heating the balancer to 200 degrees F for about 20 minutes? Should this make the balancer easier to install? Any suggestions as to how to complete the installation of this balancer would be great as I am very close to finishing this phase of my rebuild. THANKS!!

I use a thin coat of an anti-sieze compound on the crankshaft snout, and a BFH. A long-handled 4-pounder works best for me. It's also a good idea to use a piece of flat steel plate between the hammer and the front of the balancer to keep from putting big dents in it, and also to protect the outer ring from a missed lick with the hammer. The driving force should be applied only to the center hub, not the outer ring that's only held on by the bond to the rubber torsion ring.
Jerry

We have 1" sockets going up to about 4". I grab one of the bigger ones and use it to hit with about a 4lb hammer. Easier to hold and does the same purpose of the flat.

I used the BFH approach that Jerry used. Ditto on the importance of keeping the blows away from anything but the center of the balancer. I used the 2' side of a framing square as a straight edge to determine when the balancer was on far enough to line up with the water pump & generator pulleys.

Just wanted to mention that there is another option. Why not drill and tap the crank and use a small block Chevy balancer bolt to press the balancer on? I made this simple modification on my 235 and it certainly makes installation a whole lot simpler and also gives me a bolthead to grip so I can turn my engine over by hand with a socket and ratchet handle.

The drilling process on the crank is amazingly easy....the snout on my engine has a cone which kept the drill bit centered...the threads on the SBC balancer bolt are 1/2X20 and the correct finsh drill size is 29/64 bit. I used a good sharp 1/4" bit to drill in 5/8" deep pilot hole with a battery powered drill motor, then finished off with the 29/64. The crank tapped easily and now I just thread in a 1/2x20 stud, use a couple large flat washers with a dab of grease and use a nut to draw and seat the balancer. If I remember correctly, I had to cut off the SBC bolt to the proper length and used a large flat washer to finish off the install.

Making this little modification keeps my balancer out of the oven, lets me seat the balancer precisely without using a BFH and beating on the balancer.

Also might add, that the proper method of installing a front seal is to have the timing cover loose when you draw down the balancer. This lets the lubed seal surface center itself on the balancer seal surface. I'd highly recommend using a Felpro "speedy" sleeve if your balancer seal surface is showing any wear. This sleeve slides over the seal surface on the balancer without any machining and is secured with an epoxy adhesive that is supplied in the sleeve kit. I've found that Classic Parts of America sells the sleeve kit #89-111 for appreciably less money than most local vendors. By drawing on the balancer with the bolt, having the timing cover loose and using the s/s sleeve, you'll eliminate any potential for an annoying leak/weep up front, and you'll have a bolthead to grip to make those fine tuning static timing adjustments. Might just as well do it right the first time!!!

Dave

If you decide to drill & tap the crank snout, use a stud, not a bolt in there to draw the balancer into place. Putting turning stress on the thread tapped into the crankshaft will strip it out in short order. If a stud is screwed into the crank, and a nut & washer is used out front, the crank thread is less likely to strip since the stud isn't turning.

On my race engines, I use a needle-bearing balancer pusher with a 1" fine thread that I bolt to the end of the crankshaft with a long bolt, then tighten a big nut down against the face of the balancer with a Torrington bearing between hardened steel washers carrying the thrust load. The pusher takes a 1 1/2" socket or end wrench to turn it.

BTW,a small-block V-8 center bolt is a 7/16" X 20, not a 1/2".
Jerry

I just made sure neither surface had any paint etc on it, put a touch of bearing grease on it..and 3 hits with a small sledgehammer..

any problems with the key or key slot? bent, burred etc

Keith

Good point! if the drive key tries to roll out of the slot in the crankshaft, it can lock up the balancer partway on. The fix is to pull the balancer back off, and be sure the key is a snug fit in the crank, and a slip fit in the balancer slot.
Jerry

Here is another comment on the process. If you are hammering it on, it is not always obvious when the balancer is home. You can pound away and see that it isn't making progress and then up the force and it moves some. I think that getting it to line up with the other pulleys is not an extremely precise indication but it can provide some information about the process.

Jerry,

I checked the stud I use to pull the H/B's home....1/2X20 with a 29/64 drill bit. If the SBC bolt is 7/16" then obviously I didn't get a SBC bolt. I stand corrected. However, the system works fine regardless of the bolt/stud diameter and it's easy to feel when the balancer is fully seated. It sure beats beating on the balancer with a BFH!!

Dave

It's not uncommon to see SBC engines with 1/2" bolts in the crankshaft, but it's where the original hole got stripped and rethreaded. A tech inspector at the race track did that to one of my engines by trying to wrench it over and check valve lift on an engine with 11:1 compression without pulling the spark plugs. What a maroon! Of course, he couldn't find an illegal engine hidden in a phone booth!
Jerry

Those dark red tech inspectors are a pain in the neck!


Stuart

Those dark red tech inspectors are a pain in the neck!

You're obviously not a "3 Stooges" fan!
Jerry

Would it go on without the key?
Just a test.

Keith

Yes, if the key was missing entirely. It won't install if the slot in the balancer is not aligned with the key, if it's actually there. Without the key, it will eventually work loose and spin on the crankshaft snout.
Jerry