The Stovebolt Site Forums The Shop Area Engine Shop Changing out a Harmonic Balancer

I’m mulling over threading the snout of the crankshaft or not. A couple of factors; the end of the existing shaft looks like something was already done to it (not threaded) and the replacement harmonic balancer has the crank receptacle which I think is neat and would like to keep.

Also I successfully removed the oil seal from the timing cover without any damage to the cover (and patting myself on the back for doing so) then the thought occurred to me while lying in bed sleepless late night, that I may push the cover in while installing the new seal. Has anybody had success installing this seal without removing the cover. I didn’t really want to remove the oil pan if It isn’t necessary.

Your thoughts?

You did the hard part by getting the seal removed, without taking the cover off. The seal installation is easy, since you cannot use a seal driver because the snout is in the way, a wide punch (3/8") should do it if you work slowly around the edges getting it started straight and light taps careful not to get it cocked, until seated.

Crankshaft looks normal with the concave on the snout.

You do not have to thread the shaft. Millions of 235s were produced and many are still running with the balancer just pressed on as far as it will go. Hint: if the balancer is from another engine, make certain the crank groove lines up with the water pump and generator (or alternator). You can move the generator/alternator bracket slightly for alignment, but you can not move the water pump. Second hint: get the repair sleeve for the balancer and install it. Rock Auto sells them. The groove worn in the balancer's shaft (even if polished smooth) will mess up your new seal...sometimes pretty quickly. The repair sleeve makes the shaft work like new. As for installing the new seal, I just use a wooden block and a small hammer and go slowly so as to get the seal in straight when I do it this way. Good luck!

If you hammer the balancer on, first drive a wood wedge between the flywheel and the back of the bellhousing to keep the hammer blows off the main bearing thrust flange. Use a BFH and a big 3/4" drive socket to surround the hand crank lugs and an extension to keep from damaging the lugs. Drive the balancer on until it bottoms out on the timing gear.
Jerry

Does the repair sleeve use the same oil seal or is the ID slightly larger for the sleeve?

I think that I used the original seal, with a little oil/grease on it.

Wait to hear from others.

Just ordered one from RockAuto and it does state that it uses the original seal. My balancer does have a slight groove which I think would be OK but then after rethinking about it, why take the chance. I don’t want to remove that balancer again.

Regarding the balancer repair sleeve, install with some non hardening sealant.

Such a Permatex #2 or something thinner?

I have never installed the sleeve with sealer, but different folks do different things for a reason! If using a sealant, you want something real thin, and, wipe off all the excess. There is not much at all that will remain since the sleeve is a light press (will need to tap it on).

I have installed quite a few seals from the front. I use a large pipe nipple that fits the job. The standard seal is used whether or not you use a repair sleeve.

It seems to me if sealant was applied to the outside flange on the sleeve, the seal would be made between the sleeve flange and the back of the balancer pulley it should be sufficient to form a seal with getting any on the shaft so it should not interfere with installing the sleeve.

Any other “Bolter’s” out there, that installed this sleeve, please share your experience.

I usually use thread locker but recently followed the installation paperwork supplied by National which stated to use non hardening sealant, I used permatex 2, it is used to stop any possibility of the sleeve spinning on the hub of the balancer, which is practically impossible unless it was a really loose press.

The sleeve will not be installed not nearly that far because then the sleeve would be way past the seal in the timing cover.
Hint : look for the groove in the dampner before you install the sleeve, then only press it on far enough to center the sleeve on the seal.

Thanks sstock for the heads-up. I’m waiting on the seal and the sleeve to be delivered next week. I’ll update to let you all know how it went.

I received the sleeve and installed it today. The sleeve was not a real tight press fit as I expected. It’s more of a tap fit. sstock you were right as to the positioning the sleeve. Without the Permatex in my case, I think it could leak and possibly spin.

I also installed the oil seal which was also a success. I tapped it in with a cut off hardwood hammer handle and a small ball pein hammer going round and round slowing working in the seal.

Now on to the installation of the balancer. I don’t have a 3/4” socket set so I figured a 1-1/2” forged coupling and a short nipple should do the trick (I need 1-5/8” ID to clear the crank ears). I don’t happen to have one, so off to the hardware store tomorrow.

It's easier to keep the hammer blows centered if you also screw a cap onto the end of the nipple you're hammering on.
Jerry

When a replacement balancer was purchased from Chevrolet, in the day, it came with two 3/8” bolts tightened down in the two holes used for pulling it.
This in affect locked out the damping effect of the balancer.
I have found that in doing this it really makes it easier to drive the balancer on.
They came with instructions to remove the bolts after instillation.

That’s funny about the instructions! I wonder how many people left the tool attached before they added it to the instructions.

Good tip about adding the cap to the nipple!

I installed the harmonic balancer today and it went pretty well. I went to the not so local plumbing supply (a 45 minute drive) and got a 1-1/2” coupling, 4” nipple and a cap to match. The existing Woodriff key was beat up quite a bit but procurement of a new one proved to be more difficult than I anticipated. NAPA didn’t carry them, Advance Auto looked at me like I was from outer space. There was an older gentleman working there that formerly worked at NAPA and said tractor Supply carries them. TS did have them but they were in such a disarray and none were in their labeled place. Half of the plastic packages were empty. Unfortunately they did not have the right size. After wasting more than a hour, I settled on one that was the next size up figuring I could grind it to fit.

After the 45 minute ride home, I chucked the coupling in the lathe to face it off and turn down the OD to fit inside the rivets,
assembled the three pieces and my driver was set.

After comparing the oversized Woodriff key the the old one, I decided to clean up the old one and reuse it. It would have taken me far too long to get the new one to fit.

I spent allot of time fitting the key to the shaft and the balancer and cleaning up the shaft and crank snout. As a career machinist, I know you only get one shot to get it on the first time correctly so preparation is key. I oiled the new shaft sleeve then slid the balancer on engaging the key. The moment of truth arrived. Using my new balancer installation tool and a 4 lb. mallet I drove it on until the sound changed indicating the the balancer was seated. It didn’t take as much force as I expected. Five or six good solid hits and it was seated.

Thank you all for you input on my project. Your support insured a job done right!

phak1 Good use of those sorry forelgn pipe fitting,I wont use those on gas(black ones) had one crack !! Always use American fittings!!!

it !!

I bought them from my local plumbing supply and not the big box store where I would expect the cheap overseas crap to come from. I suppose you would have to ask for them.

Not all foreign fittings are junk.

Agreed. They are required to meet the same ASTM standards as domestic materials, although they are self-regulated.
50 years ago I installed a length of domestic black pipe that wasn't seam welded correctly. It leaked on pressure testing and had to be replaced. That's why you pressure test.