302 New Flywheel Vibration
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302 New Flywheel Vibration
Just finished rebuilding the 302 (auto) in my 70 PU and reinstalling. I've got a really bad vibration in park (and anywhere else) when revving the engine. I'm almost positive it's a flywheel problem. The teeth on my original flywheel where beat up so I replaced it with a new one.
The original flywheel had a large weight attached to it a couple inches from the teeth. The new one did not have this. Other than the mounting holes, it looked alot different. It didn't bother me as I figured it must just be balanced differently but good.
The engine itself is a little confusing as well. The heads take the older style exhaust port (small) gaskets. But the block takes a one piece rear seal. According to NAPA, they didn't use a one piece until 1981.
Anyway, what I'm really asking is...
Are there more than one 302 flywheel? What are the specifics on them?
Thanks!
Larry
The original flywheel had a large weight attached to it a couple inches from the teeth. The new one did not have this. Other than the mounting holes, it looked alot different. It didn't bother me as I figured it must just be balanced differently but good.
The engine itself is a little confusing as well. The heads take the older style exhaust port (small) gaskets. But the block takes a one piece rear seal. According to NAPA, they didn't use a one piece until 1981.
Anyway, what I'm really asking is...
Are there more than one 302 flywheel? What are the specifics on them?
Thanks!
Larry
Last edited by LBell101; Feb 25, 2003 at 07:18 PM.
Post Fiend
Joined: Feb 2001
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From: Iowa
302 New Flywheel Vibration
Larry
The early 302 had a 28 oz balance and then it changed to 50 oz around 1982. Sounds like you have a later model block and maybe crankshaft with the one piece seal. If you had no vibration before, hopefully you have the old flywheel around so you can figure this out. I agree you have most likely located the problem.
The early 302 had a 28 oz balance and then it changed to 50 oz around 1982. Sounds like you have a later model block and maybe crankshaft with the one piece seal. If you had no vibration before, hopefully you have the old flywheel around so you can figure this out. I agree you have most likely located the problem.
Last edited by fatfenders; Feb 25, 2003 at 07:30 PM.
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302 New Flywheel Vibration
Yeah, as fatfenders said, you've probably got an out-of-balance situation on your rotating assembly now. Ford engines are externally balanced with the flywheel and harmonic balancer and the weight you speak of is important. Ideally it woud have been best to take the entire rotating assembly in to get it balanced as part of your overhaul. You would be looking at dropping the pistons/rods, crank, flywheel and harmonic balancer out to get this done now. If you didn't change much weight in regards to pistons/rods during your overhaul, then your best bet now would be to take the original flywheel in to the machine shop and have them install a new ring gear on it and reinstall that. I think that will probably get you back in shape. Chevy engines are internally balanced and are much more forgiving in regards to this. Alot of Chevy guys don't spend the money on the balance because they never had to and then when they go to overhaul a real engine (FORD) and don't balance they run into vibration trouble.
Randy
Randy
Last edited by PigFarmer; Feb 25, 2003 at 08:55 PM.
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302 New Flywheel Vibration
Thanks guys!
I think we've figured out what happened. The NAPA part number is one digit different than what it should have been. The one I have is the same dimemsion but unbalanced. The one I should have gotten is a balanced unit. Basically one has the wieght on it and the other doesn't. Damn.
When the correct one comes in I'll compare it to the old one CAREFULLY before install.
Larry
I think we've figured out what happened. The NAPA part number is one digit different than what it should have been. The one I have is the same dimemsion but unbalanced. The one I should have gotten is a balanced unit. Basically one has the wieght on it and the other doesn't. Damn.
When the correct one comes in I'll compare it to the old one CAREFULLY before install.
Larry
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