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Discussion Starter #1 (Edited)
I just copied this from another site (motownmuscle) im on so I didn't have to retype everything...If the guy that built the engine from MM replys on the thread I made,i'll copy his post and put it here....

Long story short and im on 3hrs of sleep so please bare with me...This was a MM members car and he fully rebuilt the whole engine..Sold it to another guy and told him about the vibe and the guy never bothered to have it taken care of..Didn't drive it much and pretty much sat in storage...Now that I have it,im trying to fix it with no luck what so ever
..Not sure how the engine was put together and im thinking somthing is going on with the crank..Im thinking bent crank or spun bearing but again,thats what im thinking..Never bent a crank or spun a bearing so don't know if either will do this..
When I talked to the MM member that did the build,I think he said the vibe started a little after the rebuild..Not really sure so i'll message him with a link to this thread and hope he will add a little input on this that could help track down the issue..
Anyways,
Anything after 3500RPM will give a BAD vibe through the drive train..When I take off from stop lights or pushing the gas at low RPM to go around someone while driving,I can hear a click,click,click coming from the bell housing area..I thought it was the trans and so did the guy that built it so I replaced EVERYTHING..Flywheel,whole clutch set,throw out bearing,pilot bearing and put another trans in it that is 100% perfect as it was out of my old car..
Got everything done and was happy as hell thinking it was fixed but how wrong was I..When for a test ride and its doing the exact same thing
..
Also,
Before changing everything,the rear seal started leaking bad..As soon as I started the engine,it was dripping at idle and the drive was conisitent as in every half sec..Changed the rear seal and it didn't even last a day..Drove around (keeping it under 3000RPM due to the vibe) and after 3 or so hrs,the rear seal is leaking again..Not bad at all and after 3 weeks,oil is still full but I also don't drive it much..Heres a video I took today and just watch how bad my hand vibes on the shifter.... Thanks for any input I can get on this..

 

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need to check the bearing behind the input shaft on that trans. Remove the 4 bolts that hold the input retainer on. (Your throw out rides on it) pull the input and see if the guts are missing from that bearing. It will do just what you are explaining.
 

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Early 302 engines used a 28oz-in external balance flywheel and harmonic dampner. Post 1982 302/5.0 engines had the later 50oz-in balance.

If the harmonic dampner and flywheel are the wrong balance, it will shake like that. There's a good chance someone has the wrong dampner and/or flywheel on the engine.
 

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Discussion Starter #5
Jared,
Im sure thats not it..I took a Tremec out and replaced it with a World-class T5 from my old car that was fully rebuild with all new guts and bearings...When I took the World-Class out of my old car,it had maybe 300 miles on it and was perfect..When I did the swap,I also put brand spanking new throw out bearing,pilot bearing,50oz flywheel,clutch disk,pressure plate along with rear seal in the car....Nothing changed and still has the same vibe :( ..Car has a SFI balancer but a buddy give me a stock 50oz so going to change that tomorrow and see what happens..Have a feeling thats not going to change anything because I had balancers go bad and the front seal always leaked...The new rear seal I put in is already leaking again...
Thanks so much for the reply..
 

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Discussion Starter #6
Early 302 engines used a 28oz-in external balance flywheel and harmonic dampner. Post 1982 302/5.0 engines had the later 50oz-in balance.

If the harmonic dampner and flywheel are the wrong balance, it will shake like that. There's a good chance someone has the wrong dampner and/or flywheel on the engine.
Its a 50oz balanced 91 302 HO ..Balancer and flywheel are both 50oz..
 

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check the casting numbers on that crank, its possible that its and early 28oz crank in that motor with 50oz stuff hanging off it. Good call mike, when i read it i assumed it was known what was inside it. That is a possibility as well.
 

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Discussion Starter #8
check the casting numbers on that crank, its possible that its and early 28oz crank in that motor with 50oz stuff hanging off it. Good call mike, when i read it i assumed it was known what was inside it. That is a possibility as well.
The guy that built the engine told me the block is the OEM block for the car along with crank so everything is 50oz balance...Don't have the time or money to get into ripping it apart right now so its going to have to be parked :( ..Last thing I need is the crank to snap and trash the rest of the engine..Only thing im not sure of is the balancer..I know its a SFI balancer but not sure if its a 28oz or 50oz,I do have a 50oz a buddy give me the other day..My 5 year old is home from school (very bad cold) so not sure if i'll beable to get it done today...Heres the sale ad for this car http://motownmuscle.com/forums/show...le-black-306-HCI-5-spd-southern-car&highlight= ...Its a real shame that this is going on with a brand new build but I have no ideal on how the engine was put together :( ..So far im getting no reply from the guy that buil it and I really wanna know who built it...
 

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Just went thru something similar. "the guy" that I bought my engine from said it was internal balanced and it even came with the "right" flywheel and balancer... After starting it up and fixing a bunch of other stuff that was wrong I made a run down the track. It vibrated so bad it broke the oil pump. I beat my head a bunch trying things, I finally gave up and took it to my machine shop to have checked out and balanced. It was not at all what "the guy" told me it was. Not internally balanced, wrong balancer and flywheel, not forged, took out thrush and screwed the crank... Got screwed (thanks Bowtiepony....). Anyway, before its junk, find out what you got. Taking someone's word for it is expensive.
 

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The guy that built the engine told me the block is the OEM block for the car along with crank so everything is 50oz balance...Don't have the time or money to get into ripping it apart right now so its going to have to be parked :( ..Last thing I need is the crank to snap and trash the rest of the engine..Only thing im not sure of is the balancer..I know its a SFI balancer but not sure if its a 28oz or 50oz,I do have a 50oz a buddy give me the other day..My 5 year old is home from school (very bad cold) so not sure if i'll beable to get it done today...Heres the sale ad for this car http://motownmuscle.com/forums/show...le-black-306-HCI-5-spd-southern-car&highlight= ...Its a real shame that this is going on with a brand new build but I have no ideal on how the engine was put together :( ..So far im getting no reply from the guy that buil it and I really wanna know who built it...
An old 302 crank will have "2M" cast into it on one of the counterweights... and is visually different from the 50oz-in 5.0 crank. (less counterweight) The older cranks also come with a raised ring in the back where the rear main seal rides. You should be able to google the images.

There is a significant difference between the counterweights of the 28oz-in and 50oz-in harmonic dampners and flywheels. The 50oz-in will have a much larger weight. On the dampner, it might be almost have the circumference of the thing. The 28 will be about half as big. You should be able to look at a known unit and compare. You should also be able to visually tell the difference between a 28 and 50 flywheel. Google images might be your friend to get a reference to go by.

Good Luck!
 

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Been to that rodeo, flex plate was replaced and discarded without the shop seeing that it was part of the balanced assembly.
 

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Discussion Starter #12
Thanks sooo much for the replys guys and im now 99.9% sure its a spun bearing at the back of the engine..The guy that had the engine rebuilt replyed yesterday and here it is in the quote---->

So this was my car, and you got a hell of a deal on it.. if you want to sell it back to me in a few months for what you paid that would be cool.
Anyways here's the history on it all before I sold it. I bought the shortblock from another MM member who worked at state motor on Gratiot. It was all redone and supposedly balanced and done right. I bought the heads and cam from another MM member (both used). The distributor, waterpump, intake, exhaust, and rockers I re-used from previous motor. The rest I bought all new, like the oil pump, pushrods, SFI balancer, gaskets, etc. The motor ran like a champ the first couple years, during which I went from auto to T5 and it still ran like a champ. The flywheel, driveshaft, all that stuff is correct, since I just said it ran great with all that up until one day. I was at the dream cruise one year and did a first and second gear burnout and followed it by full dragging it up to 4th gear. After that night is when the vibration first became noticeable. It was very very minor but I could feel a little something. Drove it like that for a while until it slowly got worse. I remembered when I did the T5 swap that I did not put the alignment pins in the flywheel so I thought ok the clutch must have shifted a little on the flywheel and thats what was causing the vibes. So I dropped the trans, put a new flywheel / TO bearing / pilot bearing / new bolts and new alignment pins, also fixed the speedo gear in the trans. I didn't check the input shaft at the time and put everything back together. I was already trying to sell the car but wanted to see if I could fix the vibration. After I put that all back together the vibration was still there but it was a little better then it was before (less shaking). I thought maybe the trans was junk and the input shaft was bent but was done messing with it and just wanted it gone. Right after that I sold the car to the guy that you bought it from.

So anyway, if you swapped the trans and its still doing it, then I would start looking at the motor. I already tried pulling the belt off and running with no accessories but it still had the vibe. I would try swapping the balancer just to be sure and if that doesnt do it then take the oil pan off and check up in there, then go to the rockers, pushrods, valve springs and check there. Worse case is its a spun bearing or something else in the block.

Hope that helps and good luck.
So ^^that^^ was the info I was hoping he would post so it helped track down this issue..So the engine ran 100% perfect for the first few years then the issue started so I know its not a issue with the balance of the engine..Ive been thinking spun bearing for a week or so but without knowing how it was before hand,I wasn't sure..Had all the signs of spun bearing and one thing I forgot all about was oil pressure..Has a HV pump so engine still had awesome oil pressure but at idle,I noticed the gauge would drop all the way down then back up..When I changed the rear seal it didn't do that anymore and thats because it has brand new oil,so kinda slipped my mind :rolleyes: about the oil pressure acting goofy..Now the plan is to put the car on jack stands,take motor mount and oil pan bolts out then lift it up enough to get the pan off so I can change the main bearings...
Really SUCKS I did all this work but I had no ideal what I was getting into so it is what it is..Not sure when i'll have time to do this but when I do,i'll take pics/video as I go and report back with them...
 

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Discussion Starter #13
BTW,
Wish I got that info from him before tossing money,time and parts into it..I could of had this done a while ago but I now have to drop the trans again and put my Tremec 5 speed back in.Almost end of season so i'll do that when spring comes around,just wanna get this done and drive it a bit..
 

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Discussion Starter #15
engine balance, fly wheel wrong or balancer my buddy had a ford ,in that year there was 3 differant trans flywheel balancer combos
Its posted above that the engine ran perfect for a few years..They only have a 50oz balance for this year stock..
 

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I think its a mismatched balancer/flywheel or Trans problem or an accessory drive problem....

The Yellow Bullet where people throw out advice without reading the OP's prior posts LOL
 

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Discussion Starter #20
Not at all being funny man but you have me soo lost with your post..Im the OP/person that started this thread..If you read the post,you'll see that the engine ran perfect for a few years so the engine balance is correct..ALL newer 302 HO and non HO engines are 50oz balance,Ford didn't make 3 different balanced lower ends for them..The only other SBF's that had a different balance are older 351W's and older 302's and them are 28oz balanced...
 
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