Installing damper with hammer

[Truckedup]

An old time question and a discussion in a vintage truck forum...Many of you remember the older SBC's and other engines with a press on damper and no retaining bolt. Many including me used a hammer on hardwood or soft metal block to install the damper...
I have heard some say this can damage the crankshaft thrust bearing..Figuring the crank weighs between 50-75 pounds..and the damper being driven on absorbs some impact? How much force does get transferred to the crankshaft...? I suck at math but can force be calculated? Thanks

[lefty o]

how much force do you think it really takes to damage soft bearing material? i think most of us have probably hammered on a dampener once or twice in our life, but have learned not to.

[Walter R. Malik]

An old time question and a discussion in a vintage truck forum...Many of you remember the older SBC's and other engines with a press on damper and no retaining bolt. Many including me used a hammer on hardwood or soft metal block to install the damper...
I have heard some say this can damage the crankshaft thrust bearing..Figuring the crank weighs between 50-75 pounds..and the damper being driven on absorbs some impact? How much force does get transferred to the crankshaft...? I suck at math but can force be calculated? Thanks

WELL , what do you use when the crankshaft has no hole in the end...? Much less a tapped hole.

[frnkeore]

Maybe it was GM's way of squaring up the thrust bearing

[lefty o]

An old time question and a discussion in a vintage truck forum...Many of you remember the older SBC's and other engines with a press on damper and no retaining bolt. Many including me used a hammer on hardwood or soft metal block to install the damper...
I have heard some say this can damage the crankshaft thrust bearing..Figuring the crank weighs between 50-75 pounds..and the damper being driven on absorbs some impact? How much force does get transferred to the crankshaft...? I suck at math but can force be calculated? Thanks

WELL , what do you use when the crankshaft has no hole in the end...? Much less a tapped hole.

a BFH!

[427dart]

Any place to bolt up a homemade press bar to front of block? Wonder how they did those at the factory?

[F-BIRD'88]

If you heat it up in a pot of boiling water on the stove first you can tap it on with wood mallet with little force.
Use oven mits to handle hot.

If you hammer it on ALL THE HAMMER FORCE gets to the crank thrust bearing...

[BillK]

It probably takes all of 30 minutes to drill and tap the crank. I always wondered myself how they installed them at the factory. I am betting some type of giant fixture that went all around the entire engine and pressed from the front and back of the crankshaft ? Would love to be able to see some of the old GM machining and assembly diagrams from back then.

[GOSFAST]

For years now we'v used the "hot-oil' method to install almost all our dampers. If the correct press fit is established they go right on by hand, especially the earlier SBC Chevies!

See the photos below.

Thanks, Gary in N.Y.

P.S. As Bill mentioned above we wouild recommend definitely drilling/tapping for a bolt on the very early units. We do these even on our 100% stock-appearing builds, customers are OK with this procedure.

[Truckedup]

I have seen factory service manuals describing the tool used with a hammer to drive on the damper .Nothing mentioned about heating the damper. I drop the damper in a pot of boiling water for 15 minutes...Drilling the crank with the engine in the vehicle can be difficult...and a crooked hole...lol

[engineguyBill]

I think that GM had a fixture that was used to install the dampeners on early SBC engines that did not have the crankshaft drilled for the dampener bolt. This fixture was pretty large and cumbersome, had fingers that went behind the back side of the crankshaft, a frame that went to the front of the engine with a hydraulic arm that exerted force onto the dampener and drove it onto the crank snout. I think the engine was placed into this fixture in a vertical position with the front of the engine facing up.

On a related note, I once saw a Fiat-bodied altered with early 283" SBC revving to the moon on the starting line when the pressed-on dampener came off the engine. The dampener hit the side of a brand new Plymouth parked in the spectator area, leaving a huge dent in the front fender, then hit a spectator in the head. Don't know if the spectator survived, but it sure didn't look good. Any high RPM engine should have the dampener attached with a quality bolt . . . . . . . it's common sense and good insurance.

A hammer should never be used to install a dampener as it will compromise the thrust bearing.

[modok]

Professionals use hammers all the time and we aren't damaging anything.
You just have to learn the limits. You have to learn what is enough and what is too much. And use the right hammer and the right driver.

if you want to get it on the first try.... need to measuring the amount of interference fit and see that it is correct, check the fit of the key, chamfer all the leading edges.

Heating it up is a good idea if done right. But I would still have a hammer and driver within reach. You don't need it, but it's murphy's law that if you do NOT then the thing will get stuck on halfway.

[Dave Koehler]

I have never heard of anyone killing a thrust with a hammer install that could be confirmed.
Younger folks will certainly get their panties in a bunch over this but that was the norm.
Try doing this in chassis after a cam change.
More room in those days but it was still a short stroke process.
FWIW I did several of those as a teenager.

Now...over the top clutches were another thrust matter all together.

[benno318]

I have never heard of anyone killing a thrust with a hammer install that could be confirmed.
Younger folks will certainly get their panties in a bunch over this but that was the norm.
Try doing this in chassis after a cam change.
More room in those days but it was still a short stroke process.
FWIW I did several of those as a teenager.

I like your answer Dave.

and even worse than this is one of the common old engines we had over here, Holden 6 used a fibre/resin helical cam gear driven by a steel crank gear. of course the teeth used to strip and all of a sudden the car stops.
Nowadays the cars are worth good money so people seem to get all curious/upset when you tell them you used to repair them in-car without even taking the cam out! But back then they were $500 cars and owners wanted them back on the road ASAP so you did what you had to.

The aftermarket made replacement alloy cam gears, so you would chip away the remains of the fibre gear down to the hub, cut the steel hub from the cam, heat the new gear then fit it as much as you could (hoping you had got the timing marks correct allowing for the helical gears to align) finally hammering it home with an appropriate sized chisel wedged into the cam via the fuel pump hole to stop it driving the cam plug out!

oh, and after all this was done and you had refitted the timing cover, you whacked the harmonic balancer back on with the biggest hammer you could get to fit in there with a bit of swing, cause they werent drilled in the cranks either...

[Dave Koehler]

As you might surmise the Chevy inline 6 had the same fiber gear. It was good for business.