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302 Harmonic balancer installation issue

Bustedbroc

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Jr. Member
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Oct 12, 2023
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59
Hello folks, 1974 bone stock 302 Bronco. Replaced timing chain set, oil seal and water pump. After putting the old harmonic balancer back on I noticed it was shot. Purchased a new 3 bolt balancer from Jeff's Graveyard, https://shop.broncograveyard.com/Harmonic-Balancer-302-1969-77-New/productinfo/10412/. It looks identical. Lubed everything up and tried to install. I cannot get it on. If you look at the ID of each balancer they both have a step where the diameter is slightly smaller to ensure a tight fit the last 1/2 way onto the crank. At that step is where the new balancer stops. I cannot get it on enough to align the key in the keyway. I tried heating the inner hub portion of new balancer some and tapping on it with a block of wood and hammer but no go. With the old balancer I could slide it on far enough to align the key and then use the center bolt to draw it in the rest of the way. I do not have a linear caliper deep enough to measure the smaller ID bit it seems to me that the ID on the new balancer is slightly out of spec. I see Tom's has a harmonic balancer that replaces both 3 and 4 bolt types. has anyone used on of these?
Thanks, FM
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,944
I would check the snout of the crank very carefully. Make sure it didn't take a hit and get mushroomed out. That can make it a thou or two larger and the damper is already a press fit.
 

Double66

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Mar 18, 2017
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175
do you have an install tool?? How are you heating the hub??
Definately use an install tool instead of the crank bolt to pull in the balancer. If the bolt were to shear off in the crank it would be a bad deal. You shouldn't have to use heat for installation. If it's just a one time use a lot of the parts stores let you rent an installer for the day.
 
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Bustedbroc

Bustedbroc

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Oct 12, 2023
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Thanks for all the tips. I would prefer to use a new balancer sine mine has a slight wear groove from the old seal. I will double ck the snout but as I said I cannot get to the point of aligning/getting the key into the keyway whereas the old balancer has no such issues. I will definitely check for the installer. Tks, FM
 
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Bustedbroc

Bustedbroc

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Also, as far as warming, I just hit the center hub with a bottle propane torch a bit to get it to the starting point. Its cold up here in NY. Cold crank/warm hub, no diff. FM
 

Wild horse 75

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May 9, 2023
Messages
358
Loc.
BC
Thanks for all the tips. I would prefer to use a new balancer sine mine has a slight wear groove from the old seal. I will double ck the snout but as I said I cannot get to the point of aligning/getting the key into the keyway whereas the old balancer has no such issues. I will definitely check for the installer. Tks, FM
You can get a repair sleeve and seal to fix that.
 
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Bustedbroc

Bustedbroc

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Oct 12, 2023
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I guess that is true. I was trying to avoid removing the timing cover and resealing it.
FM
 

bronco italiano

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73azbronco

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i had issue on crank install of balancer during two rebuilds, both bad balancers, out of spec.
 

NJBronk

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Oct 11, 2022
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Just chiming in that the install tool really makes it easy. Free to borrow from my local Autozone and got it on in 5 minutes.
 

spap

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Jan 2, 2010
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As mentioned
Used a speedy sleeve on my first bronco, never had an issue.
always surprises me that a piece of rubber can wear our metal.
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
34,944
These days I figure the rubber in the balancer is shot or close to it before I worry about the groove worn in it.
 

73azbronco

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Nov 11, 2007
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Just chiming in that the install tool really makes it easy. Free to borrow from my local Autozone and got it on in 5 minutes.
I own the tools, but I was starting to bend the grade 8 washer, so I removed, measured, way to small.
 
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Bustedbroc

Bustedbroc

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Oct 12, 2023
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Thanks all for the input. I spoke with Ron from DD. Original balancer is getting rebuilt. They cut and sleeve form the groove worn. No need for me to replace the seal with oversize. That should take care of my issue.
 

mustanggarage

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Aug 14, 2018
Messages
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my dad who taught me every thing I know about mechanics would have me take a piece of emery tape and loop it around the crank shaft and see saw it back and forth until the snout was shiny and no burs present before installing a new balancer.
 

anoblefox

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Apr 24, 2011
Messages
241
use a thin coat of STP oil treatment. There is nothing better for shear/ sliding surfaces for installing bearings in a press fit situation. I would personally never use it in my engine crankcase though!
 
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