302 Flywheel imbalance

[Airmapper]

I knew I'd screw something up. I think I ordered the wrong flywheel for my engine. I don't know the exact year, but I believe it's about an '83 302.

The one I took off has 164 teeth ring and I think 28oz imbalance, because the cast balance isn't as big as the one I got.

The one I got looks right, but the cast in weight looks a lot bigger, I'm guessing it is 50 oz.

I had the good fortune to catch Elmer Fudd behind the counter today, and he just looked at me funny when I asked him to check the imbalance so I just took it and left. My bad. But still I ordered it based on an '83 302, 164 teeth, and NAPA's website doesn't give imbalance info.

So does anyone know the correct NAPA part number? (Or heck, I'm almost fed up with NAPA, so somewhere else may work too.)

 

[Broncobowsher]

Did the old one work without shaking? Does it have any numbers on it.

'82 is when the 50 oz-in came out. About an '83 is getting fuzzy at the change over time. Ford is known for not rolling out changes across the board all at once.

 

[Viperwolf1]

This should be the 50 oz version, spec'd for '86 mustang
BK 6005059
# Flex Plate Teeth : 164
Balance Weighted : Yes
Crankshaft Diameter : 1-3/4"
Flex Plate O.D. : 14.23"
Manufacturer : Pioneer Automotive Industries
Manufacturer Part Number : FRA-214

28 oz version is BK 6005012
# Flex Plate Teeth : 164
Balance Weighted : Yes
Crankshaft Diameter : 1-3/4"
Flex Plate O.D. : 14.23"
Manufacturer : Pioneer Automotive Industries
Manufacturer Part Number : FRA-205

 

[Quick & Dirty]

If you don't know for sure what year it is, or if it's been exchange rebuilt, your best bet is to drop the pan and look at the crank number on the first counterweight.

2M and 2MA are 28 oz-in.
2MAE is 50 oz-in.

1M is 289

 

[crews44]

If you don't know for sure what year it is, or if it's been exchange rebuilt, your best bet is to drop the pan and look at the crank number on the first counterweight.

2M and 2MA are 28 oz-in.
2MAE is 50 oz-in.

1M is 289

Thats some good info right there.

 

[Airmapper]

Did the old one work without shaking? Does it have any numbers on it.

'82 is when the 50 oz-in came out. About an '83 is getting fuzzy at the change over time. Ford is known for not rolling out changes across the board all at once.

No shaking that I noticed, I think it would be enough to notice with the wrong flywheel. It runs like a top, I've had very little trouble with the engine.

The number on the old one is: C5AE-6380-E

Photo below as well of old and the one I have, NAPA part #: 88161

This should be the 50 oz version, spec'd for '86 mustang
.....

Thanks again, you need a red phone, the Viper Bronco Help Hotline.

If you don't know for sure what year it is, or if it's been exchange rebuilt, your best bet is to drop the pan and look at the crank number on the first counterweight.

2M and 2MA are 28 oz-in.
2MAE is 50 oz-in.

1M is 289

This is great info, because I don't have a clue what the PO did with this engine. I didn't know till like a week or two ago when I pulled the seal it wasn't the original 302 it came with. I haven't been able to find the casting #, scraped around under the pass. exhaust and never located it. Even if I did, heck it may just be the a block and the rest off another year.

Thanks for all the help, this is probably beginner stuff, but I am a beginner I guess, never done this before.

 

[barronj]

Thats some good info right there.

No joke! My only problem is how to file that away so that when I need it down the road, I can find it again.

 

[Airmapper]

I checked the crankshaft, 2MAE.

According to Quick & Dirty, this should be 50oz. How is it possible for me to have had a 28oz flywheel all this time and not noticed some shaking at idle? Is it just not that pronounced?

I've been having issues with it on takeoff, but not during driving or at idle.

 

[Airmapper]

Any ideas? I'm still kinda hung trying to figure out which one is right. What are the symptoms of flywheel mismatching?

 

[broncnaz]

Sometimes the harmonic balancer will absorb the vibrations up to a point. So at idle and lower rpm's it may not have been noticeable. Basically mismatched symptoms should be engine vibrations. Its always possible that the PO had the crank balanced to 28 oz.

 

[barronj]

Take your harmonic balancer off, take it & your old flywheel, your new flywheel, and the data from the crank, and head down to your friendly machinist & have him sort you out. Good luck!

 

[Airmapper]

Is there any way to ID the harmonic balancer without removing it?

I really appreciate the assistance, believe me I need all the help I can get. But really I'm having a hard time grasping the idea this is as complex as suggested, I wouldn't think tearing down the engine and outsourcing work to a shop is necessary to get the correct flywheel. I mean hell there are only 2 choices, 28 or 50.

I ID'ed the crankshaft as 50oz if Quick & Dirty's info is correct. Now I didn't notice any machine work done to it if there was, I'm not sure what to look for, but the counterweights didn't appear to be ground or shaved off, had a normal cast surface look to them.

If I can ID the balancer, then I have another piece of the puzzle. Leaving me with the correct flywheel, if I understand this correctly?

 

[BDAZSVT]

I am not an expert but shouldnt a C5AE-6380-E
be 28oz? C5 would be a 65 date. I would assume a 50oz would an E_ number.

 

[Airmapper]

I am not an expert but shouldnt a C5AE-6380-E
be 28oz? C5 would be a 65 date. I would assume a 50oz would an E_ number.

I'm 99% sure the flywheel that came of is 28oz. What I don't know is if the wrong one was on there to begin with, or if I need to keep it at 28oz.

My assumption is the PO used the Bronco's original flywheel when they stuck a newer 80's 302 in. That is why I'm having a hard time with this, I need to be able to check the rest to see if they intentionally fixed it to run 28ooz imbalance, or just did a hack job, which I suspect since I've been finding dumbass fixes all over this Bronco.

 

[pcf_mark]

i had the incorrect flexplate on their for a few months but drove it sparingly. The idle was pretty good but going down the road it would vibrate and when you got off the gas it would vibrate through the chassis. It was very low frequency no super obvious. My Dad could not detect it just thought it was old car syndrome.

 

[TwoDalesDad]

Believe ME....When I was Running a Shop I Tried Extremely hard Not To Have the same problems happen to my customers.....That Had Happened to me....When The Shop Is Busy...and things are flowing at normal speed.....There are so many greesey parts running through the steam cleaner....that parts...R...Parts...they fall into the next basket....without REAL CARE PLACED HERE.....THINGS GET MISMATCHED.....

 

[Airmapper]

Does anyone know how to properly align the flywheel when I put it back on? This one does not appear to have any line up method.

I'm still looking for how to identify the harmonic balancer.

 

[rastiss]

due to bolt spacing, flywheel will only go on in one position. unless you use a reamer....

 

[broncnaz]

X2 all the bolt holes only line up one way. As for ID of the balancer usualy the casting number is on the rear so removal is a must. now you can look to see how many bolt holes it has 3 and its likely to be a bronco balancer 4 and it could be off about anything else both 28 and 50 oz.

 

[Airmapper]

Thanks, I had in my head those holes were evenly spaced. I had read about some 302 flywheels needing to be lined up manually (no forced alignment) I assumed I had one. After I read these replies I went to look again, it's hard to tell by eye, but I dug out my calipers and found one hole a little off pattern.

now you can look to see how many bolt holes it has 3 and its likely to be a bronco balancer 4 and it could be off about anything else both 28 and 50 oz.

Mine has 3. I guess I'll reluctantly take it off and find out for sure. If the crankshaft is indeed 50oz, I need to make it all match.

Thing is I really hate to put much work into the engine. I even decided not to replace main seals and such because I'm not really sure if I'll keep it or not. Just planned to run it as is until I made up my mind to rebuild the 302 or swap in a 351W.