Harmonic balancer 340

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Majestic

Majestic

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I have bought pulley after pulley and none have worked. I think my harmonic balancer must not be seated all the way. Anybody have any measurements or should I just try to tighten it.
 
Majestic said:
I have bought pulley after pulley and none have worked. I think my harmonic balancer must not be seated all the way. Anybody have any measurements or should I just try to tighten it.
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Post a picture of the balancer on the engine. Otherwise we will just guess
 
Here's my pic. Hope it shows up. First time using pics on here.
 

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I think the lettering says "Use with 340 cast crank only". As far as I know, there is only 1 cast 340 crank damper.....used in both late '72 and '73??

OP, can you snap and post a pix from the side, showing the relationship between the timing cover and the back of the damper.

Is the problem that the pulleys are too far out to align with the alternator, PS pump, etc? Have you torqued the damper bolt to final torque? It is quite high, like 135 ft lbs.
If you torque on the damper bolt, it ought to slowly pull the damper in with a steady torque level, and without having to go any where near to the final torque level. When it seats, the torque should very suddenly go way up.

If it starts to bind up as you pull it in, then you may be having some interference between the crank key and the key slot in the damper; I would then recommend removing the timing cover and seeing if the damper seats against the slinger and the crank timing sprocket.
 
Ok I will get some more pics tomorrow. I just had this motor put in and not sure what he torqued it up to. I appreciate everyone's help. It's getting in my pocket buying pulleys and not working. It has to be something with the balancer.
 
73 was the only year for a cast iron crank in the 340.
 
I thought they put them in some of the late production '72 models too.....or is that when 360's came out?
 
krazykuda said:
73 was the only year for a cast iron crank in the 340.
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Um no they also came in 1972.

Question for the original poster, are you using the new 1970 and up style timing chain cover that has the timing marks on the drivers side, if so I can measure from the back of the cover to the edge of the balancer to give you an idea if it is seated all the way on.
 
awh....google...

Note: In ’72, the cast crankshaft replaced the forged crank in production on April 11,1972 with 340 engine #HM340R-3911-8000. Damper stamped ‘Use with 340 cast crank only’
 
70aarcuda said:
awh....google...

Note: In ’72, the cast crankshaft replaced the forged crank in production on April 11,1972 with 340 engine #HM340R-3911-8000. Damper stamped ‘Use with 340 cast crank only’
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So they pulled it ahead for the last two months of production for 72...
 
sireland67 said:
Um no they also came in 1972.

Question for the original poster, are you using the new 1970 and up style timing chain cover that has the timing marks on the drivers side, if so I can measure from the back of the cover to the edge of the balancer to give you an idea if it is seated all the way on.
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Yes the marks are on the driver side. That would be a big help. Thanks
 
This is the best picture I could take, had to hold a flashlight in one hand and the camera in the other.
Picture is of a 1972 340 cast crank, factory balancer and timing cover.
The measurement is 2.4" from the timing chain cover to the back side of the balancer.

hF9M0y.jpg
 
Our 340's damper is about 1/8" from the raised timing mark area, and the back of the damper is about the same distance to the mounting ears of the timing cover. (It varies from 2.3" to almost 2.5", depending on where I measure to.)

(BTW, our damper is a neutral balance with an earlier crank.)
 
nm9stheham said:
Our 340's damper is about 1/8" from the raised timing mark area, and the back of the damper is about the same distance to the mounting ears of the timing cover. (It varies from 2.3" to almost 2.5", depending on where I measure to.)

(BTW, our damper is a neutral balance with an earlier crank.)
Click to expand...

1/8" from the raised portion sounds right, you can see the raised part of the timing marks in the very top of the photo I posted.
 
I going to assume for a second that his balancer is fully seated.
The next thing to check is:

What accessories are you trying to align, you may need all the brackets and pulleys, from a 70 up Mopar to get everything to align correctly.
Pre-1970 brackets are different than post 1970.
 
dano said:
So what is your fit issues with the pulleys?
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The crank pulley is too far out to align with ac pulleys. The alt. and ac pulleys line up with each other. It looks like I'm about a 1/4" out too far. I'm gonna check the measurement you all gave me when I get home. Thanks again
 
So I measured the balancer. It was 2.75 from cover and .5 from timing marks. So I think its close to 3/8 off. I removed the crank bolt and the threads have minor damage. Do I need a special tool to remove the balancer?
 
What are the chances your thrust bearing is kapput? I think there's only about 1/8 " to be had there, but I guess it's worth a check.
I pulled a teener once, with a shot bearing. The TC bolts were cutting a channel into the back of the block already.They had "machined" their way into the rear cam plug. It required brazing to repair, and the crank was junk. I think I tossed the rods too. The block lived. It became my winter motor, years ago.I can't say it's related but the tranny behind it was puking oil too.

Easy check; just pry the balancer forward, then push it to the rear. End play usually falls around .007 to .010. It should not "clunk". .010 is about the thickness of two or three pages of newspapers.
Yes you need a special tool to pull that balancer off. And a longer bolt plus some anti-seize to reinstall it.
I'm not sure removing it will accomplish anything. There's nothing in there to prevent the balancer from seating. With the possible exception of the oil flinger. I suppose it could have become dislocated from the key during a careless damper install, but that's nearly impossible. Even if it was on backwards, once the cover is on, I don't think it can move forward enough to come past the key.Anybody know for sure?
 
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