harmonic balancer bad?
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Mountain Pass
Joined: Jan 2014
Posts: 170
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From: South Carolina
harmonic balancer bad?
I have at idle up to maybe 1000 rpm an oscillating vibration that you can actually see. It's very slight but it's there. You can feel it when your sitting in the truck. Once you get above 1200 or so rpm's you can't tell anymore. I've never had a truck that did this so I figured I'd put it out there. But it's oscillating, not constant. Like every 2 seconds or so it comes around. Just curious if anyone ever had this and if so is it harmonic balancer related. Thanks
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My 85 had a shake like that, I was fairly certain it was injectors, but I rebuilt a different engine for it and used the same ip and rebuilt the injectors and the shake didn't transfer...used the same harmonic balancer (couple years old) and the same flywheel and clutch (three years old and like new)
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Mountain Pass
Joined: Jan 2014
Posts: 170
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From: South Carolina
Lonewolf, it doesn't surge. The idle stays the same but the vibration comes in 2 second waves. I don't know the history of the truck so who knows what flywheel I have . Most likely stock original.
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That's what mine did, you couldn't see it in the tach, or the tail pipe, it just vibrated off off on off off on off off on. It was weird how it came and went consistently. You could really feel it if I put my hand on the gearshift
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Mountain Pass
Joined: Jan 2014
Posts: 170
Likes: 10
From: South Carolina
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Does the motor change tone when it misses?
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Scope Wizard
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weird..I guess a dual mass flywheel can cause vibration before you would get the classic thudding or clunking
easy enough to check the Harmonic balancer visually.
you might be able to track down the vibration with a Strobe light.
sorry I thought at first it was a Surge.
easy enough to check the Harmonic balancer visually.
you might be able to track down the vibration with a Strobe light.
sorry I thought at first it was a Surge.
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Mountain Pass
Joined: Jan 2014
Posts: 170
Likes: 10
From: South Carolina
It doesn't miss or anything. It runs and sounds great. Was feeling pretty good about it all. Went out today and I just had a feeling to check the driver's side valve train. That's where I found a broken head bolt in January. Pulled the valve cover and found another broken head bolt. Cylinder 6 at the exhaust pushrod. Almost right in the middle of the head. I guess they have been stretched being torqued so many times. Going to pick up a leakdown tester Lonewolf. Going to check the cylinders, And being that it looks like I need head bolts, I might as well do studs. While I'm at it, head gaskets. Honestly I'm starting to get tired of tearing this down and putting it back together stuff.
Posting Guru
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Sorry to hear the bad luck, call arp for the stud part number for a single stud, a nut, and a washer, then check distributors/dealers and find a good price. Just tell arp you just need a couple that stretched on you so they don't try and just give you the set number. That's what I did. My studs were bigger than yours yet cheaper....
I would highly recommend Allen Bailey with Allen's fasteners, he gave me a song of a deal on my 9/16" stuff. Ordered two extra of everything just incase and it was $495 shipped!
If he doesn't stock it all, he also will ship you what he has, them send the rest when he gets it in a few more days for no extra charge. That way you can at least get started.
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Mountain Pass
Joined: Jan 2014
Posts: 170
Likes: 10
From: South Carolina
I found a site that's selling them for around $250. I'll check out Allen's. Fel Pro gaskets are the way to go also? I'm hoping I find what's causing me to burn some oil on steep hills. Just got the fuel dialed in. If the truck was a Lariat, I wouldn't mind the extra work, but it's an XL, doesn't even have air.
Posting Guru
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I found a site that's selling them for around $250. I'll check out Allen's. Fel Pro gaskets are the way to go also? I'm hoping I find what's causing me to burn some oil on steep hills. Just got the fuel dialed in. If the truck was a Lariat, I wouldn't mind the extra work, but it's an XL, doesn't even have air.
Justin (R&D) told me all the gaskets are equal, and he also uses 7.3 gaskets on everything.
Are you turbo?
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Mountain Pass
Joined: Jan 2014
Posts: 170
Likes: 10
From: South Carolina
No turbo, but it would be nice. Lol. I thought the 6.9 gaskets hat the cutouts for the coolant passages that the 7.3 doesn't. This truck warms up fast and has great heat.
Posting Guru
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Apparently they ditched that grommet area because it makes them too weak. He says it won't make it run any hotter if you use the 7.3 gaskets.
Until my truck gets done I won't know either but it seemed to run just fine temp wise the little bit I drove it.
Until my truck gets done I won't know either but it seemed to run just fine temp wise the little bit I drove it.