1980 Chevy Harmonic Blancer replacement

old · May 30, 2019

So my tractor hauler which is a Chevy heavy half 4X4 pick has a bad blancer that I need to replace. So can it be done with out pulling the radiator?? Looks like there is room but also looks like it will be a blind spot type of job. So any body replaced one and if so how hard a job. I'll be needing this when I get the Mahindra done to haul in a MF85

Bob · May 30, 2019

No problem to pull balancer without removing radiator.

Cover radiator core with a heavy piece of cardboard to prevent damage, tho.

I assume you have a suitable puller and a damper re-installation tool?

old · May 30, 2019

Puller yes but a device to install no

CenTex Farmall · May 30, 2019

The installer is a "must have" as the balance is a press fit and hammering is an absolute no-no.

Most chain auto parts store have tool rental programs. You pay a deposit and get it all back when you return the tool.

You can make one on a lathe or by welding a bolt onto a large piece of all thread.

"while you're in there" it's a good idea to change the front seal.

rustred · May 30, 2019

I worked in a GM garage and changed many timing chains on those engines. puller yes, but have never used an installer nor seen any other mechanic use one. I always used a brass drift . they do not go on that hard. plus once part way on you can use the bolt and washer to push the damper home.

CenTex Farmall · May 30, 2019

No, it's not a heavy press fit.

Sometimes on brand new ones, depending on manufacture, they can be a good medium fit. Did have one I bought where the ID was 1.5 thousands smaller than the crank snout! You would never beat than on with any size hammer. Used, yes you can pull it on with the bolt and I have done that before, a long time ago. It's riskier to the threads inside the crank snout though. I have seen cranks with stripped out threads before.

That's why, sight unseen, I recommend the installer for the OP. Also, not much room to swing with the radiator in place.

JDEM · May 30, 2019

I just put the balancer-pulley back on my 1994 350 engine. No way would I drive it on with any punch. It fits pretty tight and I am not going to subject an engine to that kind of abuse (unless I am mad at it and junking it).

I had no trouble coming up with a threaded rod and nut to push it back on.

Hey, you pulled it off and likely have an idea of how tight a fit it is.

Also, as Bob already stated - there are local auto parts stores with free tool rentals. I know my local Autozone does it. I simply already had what I needed.

timcasbolt · May 30, 2019

(quoted from post at 19:23:52 05/30/19) I worked in a GM garage and changed many timing chains on those engines. puller yes, but have never used an installer nor seen any other mechanic use one. I always used a brass drift . they do not go on that hard. plus once part way on you can use the bolt and washer to push the damper home.

I've put 'em on with a post mall, but I wouldn't do that today. Too many potential problems doing it wrong when all you have to do is do it right.

Steve@Advance · May 30, 2019

While you're that close, might be a good time to do the timing chain if it's high mileage and never been done.

4wdtom · May 30, 2019

If the end of the crankshaft is threaded so you can pull it on I would. You don't want to be hammering on the end of the crank.

wilson ind · May 30, 2019

installer for the op?? you mean the dampener ?? Do not know what part you are referring to?

tomNE · May 30, 2019

dampenor is fairly easy but if you have never installed a chain on a small block; have someone talk you thru that once before starting. easy enuff job if you know the tricks. chain is a peice of cake but getting the cover off and then back on without any leaks can try your patience!

CenTex Farmall · May 30, 2019

OP= Original Poster, i.e. the one who posted the original question.

I recommended using a "made for" dampener installation tool.

CenTex Farmall · May 30, 2019

Been a while since I worked on a small block, but I remember that there are two different thicknesses for the half circle shaped rubber gasket that goes between the bottom of the cover and the front of the oil pan.

To get the cover that's made for the thicker one out you pretty much have to loosen some of the oil pan bolts toward the front and get the oil pan to move down just a bit. As you say, a bit of a pain. Brake cleaner and RTV to the rescue!

Small block is easy enough to turn by hand so you can feel if there's significant slack in the timing chain before you open it up.
Summit has a good price on full roller, double row timing sets in their house brand. Made over here IIRC.

Determined · May 31, 2019

(quoted from post at 11:56:28 05/30/19) So my tractor hauler which is a Chevy heavy half 4X4 pick has a bad blancer that I need to replace. So can it be done with out pulling the radiator?? Looks like there is room but also looks like it will be a blind spot type of job. So any body replaced one and if so how hard a job. I'll be needing this when I get the Mahindra done to haul in a MF85

You did not mention what size engine in your truck.

Your 1980 heavy half may have come with the 400 small block in it.

If yours has a 400 it is externally balanced, the balancer, flexplate and or flywheel are weighted and are application specific to the 400.

One from a 350 will physically fit on it but it will shake and vibrate itself to death.

old · May 31, 2019

It has the 350 4 bolt main engine ion it

1980 Chevy Harmonic Blancer replacement

old

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