[69_cat]

So I’m assembling my 69 351w straight out of the machine shop and my harmonic balancer slides on by hand. I assumed the one I got was Chinese crap with poor tolerances so I dug out the original and it now slides on by hand even though we used a tool to get it off. All the machine shop did was clean and polish the crank so I don’t think they had anything to do with it, but this doesn’t seem right. The only thing I could think is the factory balancer had paint inside and out so that could have added the thickness I’m missing (.004). My cousin has advised me to paint the inside like factory and put blue loctite on and wait to replace it when I can afford a forged crank. Let me know what y’all think, this was an 160,000 mile H code that I’m turning in to a 350-375 horse street engine, I’ll probably only take it to 5,000 rpm. Also let me know what the risks are if you think it is a bad idea to keep this crank.

 

[69_cat]

So I got in contact with my machine shop and they said they’ve never heard of this happening. The only advice they gave me was to “mushroom” out the woodruff key with a hammer and screwdriver so it doesn’t slide around (mine could be put on and taken off by hand) and maybe that’ll make the balancer a press fit as well. They said they weren’t concerned about the harmonic balancer because it’s torqued to 100ft/lbs so it shouldn’t move anyway. What do y’all think, should I take the pan and cover off and buy new gaskets just to mushroom out the woodruff key or not worry about it? Should I be concerned about the balancer being lose? (I feel like it was press fit for a reason) I have no idea what to do here, both solutions take a lot of time and/or money so I’m kinda leaning towards just torquing the balancer on but I don’t want to have my $3,000 engine build blow up.

 

[85ltdcrownvic]

I would not do that. If the machine shop is suggesting that, it’s not a good machine shop. Do you have a caliper to measure the crank snout? I’m willing to bet they machined it instead of cleaning it up. They should fix it imo.


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[69_cat]

I would not do that. If the machine shop is suggesting that, it’s not a good machine shop. Do you have a caliper to measure the crank snout? I’m willing to bet they machined it instead of cleaning it up. They should fix it imo.


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I measured and I’m only .004 off and there’s still rust blemishes on the snout of the crank so I doubt they machined it, but I guess that is a possibility.

 

[85ltdcrownvic]

.004 from where it should be or before? What about the size of the inside of the balancer?


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[69_cat]

.004 from where it should be or before? What about the size of the inside of the balancer?


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The balancer is .004 larger than the crank snout if my harbor freight measuring tools are accurate.

 

[85ltdcrownvic]

The balancer is .004 larger than the crank snout if my harbor freight measuring tools are accurate.

It’s accurate enough. Yeah it sounds like it was at least touched. The thing is it needs to be pressed on or you run the risk of it slipping. I don’t see how what they suggested would fix it. All that would do is mess up the crank more. It can’t be safely used now, push them to make it right. I wouldn’t trust it the way it is.


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[Big Block Ford]

Does it slide the full way on. Usually you can slide it partially on then it needs to be put the rest of the way with either a pulley installer or often with the crank pulley bolt.
The correct way is the installer tool but usually its the bolt that gets used.

 

[69_cat]

Does it slide the full way on. Usually you can slide it partially on then it needs to be put the rest of the way with either a pulley installer or often with the crank pulley bolt.
The correct way is the installer tool but usually its the bolt that gets used.

It slides all the way to the timing gear

 

[jwko]

Are you sure you got your original crank back and not an exchange?

 

[69_cat]

Are you sure you got your original crank back and not an exchange?

I believe so, it still has the c9 part number and Ford stamped on it

 

[69_cat]

So what I ended up doing was I took out the woodruff key and put red loctite in the channel, put the woodruff key on and used a center punch on either side of it on the crank (machine shop’s recommendation) to snug up the crank to the woodruff key (it was obvious this has been done before). After letting the loctite dry I put my harmonic balancer on with blue loctite on about 2/3 of the inside bore so it wouldn’t squeeze out and cause my timing gear to stick, I also painted the inside. To make sure it was all the way seated I used a harmonic balancer tool I rented and it did nothing so it was definitely all the way on the crank. Before the loctite dried I torqued the bolt down with blue loctite on the tip and anti seize towards the top that may get exposed to moisture. I’m keeping my fingers crossed that this works, it survived the first start up so it should be fine for 100,000 more miles… right… I’ll let y’all know what happens.