engine vibration

[steelworker77]

Well what I thought was just driveline vibration on my 71 with a 302 stock 3speed seems to be engine vibration. Just got this rig about a month ago and trying to really make it dependable as a daily driver/nice cruiser. Just installed WH 2 1/2" lift with bilstein shocks and that made a massive difference. You can cruise at 60-65mph with one hand on the wheel comfortably.

Issue is I am getting a vibration starting around 2k and gets worse at high rpms. Its by no means rattling your teeth out or anything like that but there is definitely something there. I knew the 302 was from a later year something as there was a plugged oil level sensor hole in the pan. After checking the date code on the block its a E0AE which should be 1980 full size car if I am correct. I believe this is when the switch from 28-50oz balance was. Meaning it really could be either at that point. I am wandering if the donor motor was a 50oz motor including balancer and the stock 71 flywheel was used.

How bad of a vibration would I have? I really dont want to tear the trans out of this thing for no reason if I dont have to. Guessing I could start at the balancer and pull that and see if its a 28 or 50? Any other ways to tell without pulling it?

I originally thought it was driveline vibration as there was a bad u joint that was just replaced but the vibration goes away if you push the clutch in while driving. And just sitting still and holding rev's you get the vibration.

Thoughts?

 

[blade]

Does the engine have v belt or serpentine setup? If they ran the original setup with the older harmonic balancer that could be a problem also. If that is the case the flywheel is probably wrong too.

 

[steelworker77]

V Belt setup. I am reading it was late 81 till they made the switch to 50oz. Being a 1980 date code I guess it could go either way???
Are the timing marks different on the balancer from 1971 to 1980 just so I can try and determine if the balancer is original to the motor. Then I would at least maybe know if the motor should be 28 or 50oz balance and can go from there. Being a 1980 it seems it could go either way.

 

[steelworker77]

Well balancer looks in good shape. Has E4TE stamped on the rim with the timing marks so im assuming an 84 which would be 50oz. It definitely feels like a balance issue.

Wonder if I could pull a drain bolt and stick a bore scope In the oil pan to see the crank and check for markings. Either the flywheel is wrong weight or balancer or both.

 

[steelworker77]

Couldn't see anything crankwise. Flywheel is definitely a 28oz after pulling starter to see. So balancer is a 50 and flywheel is a 28. Wandering which one is correct? I have a hard time believing that isnt the original balancer but would a E4TE balancer be on a e0ae motor?

 

[jamesroney]

Couldn't see anything crankwise. Flywheel is definitely a 28oz after pulling starter to see. So balancer is a 50 and flywheel is a 28. Wandering which one is correct? I have a hard time believing that isnt the original balancer but would a E4TE balancer be on a e0ae motor?

What's the date code on your E0AE block? (and no, the engineering number of "E0AE" is not a date code...)

The E0AE-6015-D3C ran thru the conversion from 28.2 to 50 oz imbalance. I'm pretty sure you could get a E0AE from 1980 to 1986 in the truck.

Regardless, no one can know what crank is in your 40 year old block. And unfortunately, a rebuilder could have changed them out. Most likely, with an E4TE balancer, it is an 82-86 50 oz crankshaft. But the only way to know for sure is to pull the pan and look at the crank. You can go by the crank stamping, or you can look at the internal weights and tell right away. (I can't, but I am told that an expert can see the difference from about 10 feet away...)

And yes, the E4TE balancer could most certainly have come on an 84-86 EOAE block.

 

[steelworker77]

Would make more sense with it being newer than 1980 as there is an oil level sensor plugged off in the side of the pan. I will check for the actual date code. When was the switch from 2 to 1 PC main seal

 

[jamesroney]

Would make more sense with it being newer than 1980 as there is an oil level sensor plugged off in the side of the pan. I will check for the actual date code. When was the switch from 2 to 1 PC main seal

11/30/1982

 

[steelworker77]

Just an update. That was indeed the issue. New 50oz flywheel and clutch installed. No more vibration. Was able to button up some leaks while it was apart as well. Couldnt be happier.