crank damper attachment....
How did GM service techs install the crank damper at dealerships when there are no threads in the crank? Hammer it on and ignore possible damage to the thrust bearing or it there a better way? Heat, and if so how much before the front seal is damaged? This engine is installed in a 1966 Corvette. Can the crank be drilled with motor in the car? Thanks for any advise. Bill
-
-
Re: crank damper attachment....
Bill-----
My expectation is that field installation of balancers on engines without crankshaft balancer bolt tappings was done using impactive force (i.e. "hammering it on"). They may or may not have used a plate to spread the force. The reason I say I expect it was done this way is because I know of no other way to do it.
At the engine plants, these balancers were installed using a large set of tooling which included an hydraulic press. Such a device was never available in the field.
I have heard that the balancer bolt tapping can be done with the engine in the car. However, I think it requires a special jig to get it right. The drilling and tapping MUST be "straight-and-true".In Appreciation of John Hinckley -
Re: crank damper attachment....
Every manual I've seen says to hammer it on. I did that to mine 25 years ago. Never a problem.
Comment
-
Re: crank damper attachment....
Richard------
The problem with hammering on the balancer do not just involve damage to the balancer. The other problem is damage to the crankshaft thrust bearing and crankshaft thrust flange. Damage to the flange usually results in making scrap metal out of the crankshaft.In Appreciation of John HinckleyComment
-
Re: crank damper attachment....
Joe & Richard,
I will try a little "light force" and see what happens. Since the original damper is removing itself I will recommend the owner get a new one. Something tells me if we reinstall the original damper it will work loose in a few miles. Thanks for the advise! Back to the gararge. BillComment
-
Re: crank damper attachment....
Joe,
Yes I totally agree that it's one of the processes in the service manuals that I never could understand due to potential damage as you specified. But that is the only way to install it when engine is installed, right?....force it on. I cringe when this task needs to be accomplished on the un-tapped crankshafts. I'd imagine many thousands were replaced this way in service shops. The link I posted above shows that process and every manual I own shows it the same way.
I suppose on a pulled engine with removed transmission, you could back-up the rear drive-flange of the crankshaft against a wall or vertical column to counteract the hammering effect. This is probably a good thing to do on new rebuilds if the owner doesn't want to take a deduct on a threaded snout. BTW, most Mechanical judges I've OJ'd with look in the crank for threads on the engines that didn't use the bolted-on HB.
The way I do it, is to install my HB remover tool flange to the face of the HB, tightly bolted with short 3/8 UNF bolts. I lube the crank snout and the inside of the HB with a light penetrant, then using a 6" long 4x4 wooden block on end against the flange tool, I drive it home using a 4 lb hammer. (squinting and curing my lips in the process)
Bill,
Yes, I highly recommend you get a replacement balancer. I had a marginally fitting original damper on my 270HP '59 when I got the car 27 years ago. I found out that they WILL remove themselves. Going down the highway one day after work, I heard a big bang, looked in my side view mirror and this orange and black thing appeared in view, proceeded to pass me in the left lane and find it's way into the median. It took me quite some time to find it in the grass. Had to get flatbeded home, a 3 or 4 hour ordeal IIRC.
I got a replacement from my local Chevy dealer. I installed it using the above method while the engine was installed. There was no other way to do it, short of pulling the engine. I folowed the servicae manual. As mentioned, 10 years later I rebuilt the engine(tired, oil burning, etc), and then had the snout threaded for the 7/16-20 bolt at the recommendation of the machinist.
Drilling and tapping the crank with the engine installed is a difficult task. I wouldn't attempt it. I did one with the engine on a stand and it was a chore. I feared breaking the tap the most. Then if you did fail somehow you have to hammer the HB on regardless.
RichComment
-
Re: crank damper attachment....
Even the bolt on balancers are not are "sure to stay put" item. I went to use my bolt to bar the engine over while adjusting my valves (Hinckley/Williams method) and found it to be loose. Once I re-torqued it, it worked fine.
Stu FoxComment
-
Re: crank damper attachment....
I watched a service tech at our local Chevy dealership install one in the 60's, among other things. Bill used a 2 or 5 lb hammer as I recall. He began with a piece of wood between the balancer and hammer but that soon went away. SteveComment
-
Re: crank damper attachment....
Bill, damper install section from 1957 pass car shop manual. Gary....
Install Harmonic Balance 1957 Shop Manual.jpgNCRS Texas Chapter
https://www.ncrstexas.org/
https://www.facebook.com/profile.php?id=61565408483631Comment
Comment