360 vibration = flywheel or balancer?

[russ8877]

I bought someones abandoned project as a parts rig. It had a 360/T176/d300 already bolted together. He said the 360 was out of a Waggy, so it's probably safe to assume it was an auto tranny, and the flywheel was swaped onto this motor from something else. I droped the whole pig into a cj5 and finished the details.

It runs great EXCEPT for a vibration around 2000-2500 rpms. It's far more noticable with a hand on the steering wheel, than a hand on the carb. It's not a driveline vibe. It vibrates sitting still, just as much as going down the road.

A couple questions about flywheels.
1.Does a 304 have the same flywheel balancing as a 360?
2.Could he have installed a 258 flywheel?

Would it be worth the money to try a fluid filled harmonic balancer first?

Thanks for any help you can offer.

[grignac48]

The AMC engines are externally balanced, so if the flywheel was changed it has to be balanced with the specific crank. Doesn't matter if it came from another engine. May be part of the issue. When the trany was changed if they did not put the bushing in the end of the crank for the transmission that can cause wobble and vibration.

Good luck :shock:

[tufcj]

258 is neutral balanced, 304 is different from a 360 is different from a 401.

Some people get away with a 304 flywheel on a 360, some vibrate. Best bet is to find a known 360 flywheel and swap it in.

Bob
tufcj

[LanceM]

Sorry to bring back an old post but was wounding what info i'd need to know to tell the machinist to balance my 304 manual flywheel for my new 360 engine which had a auto flexplate on it? Or is it to late now that my engines aready built and in the jeep? It's been balanced and bored 40 over if that makes any big dfference?

Many Thanks

[tufcj]

If it was balanced with the manual flywheel as part of the build, then you're good to go.

Part of the balancing process is spinning the crank/harmonic/flywheel as a set, and adding or removing weight as needed.

If it was balanced with the automatic flexplate, then you swapped on the flywheel, I'm sorry to say you wasted your money on the balance job :smile: , since you now have an unmatched component in your system. If that's the case. and you still have the flexplate, you can have the flywheel "match balanced" to the flexplate, but you will need to take it off and deliver both to a machine shop.

Bob
tufcj

[LanceM]

Well not good, the engine didn't have any flywheel or flexplate on it when it was done :smile: you'd think my engine builder would have known this :roll: but i do have an old 360 flexplate kicking around so i'll take that in with my 304 flywheel and get it matched

Many thanks

[LanceM]

Well it's time to take the flex plate and fly wheel into the machine shop to get matched up, but i found two flex plates in my pile of parts. Are they both AMC 360 flex plates? And to make sure my fly wheels off a 304 and not off a 360 i've posted some pics of it too :-|


Flex plates

http://img219.imageshack.us/img219/1566/1001552j.jpg (http://img219.imageshack.us/i/1001552j.jpg/)

http://img255.imageshack.us/img255/2186/1001553.jpg (http://img255.imageshack.us/i/1001553.jpg/)

http://img153.imageshack.us/img153/3873/1001554.jpg (http://img153.imageshack.us/i/1001554.jpg/)

http://img697.imageshack.us/img697/4797/1001555ua.jpg (http://img697.imageshack.us/i/1001555ua.jpg/)

Pics of my 304 fly wheel?


http://img202.imageshack.us/img202/2872/1001543.jpg (http://img202.imageshack.us/i/1001543.jpg/)


http://img219.imageshack.us/img219/6459/1001548e.jpg (http://img219.imageshack.us/i/1001548e.jpg/)


http://img163.imageshack.us/img163/2174/1001549d.jpg (http://img163.imageshack.us/i/1001549d.jpg/)

http://img405.imageshack.us/img405/4817/1001550v.jpg (http://img405.imageshack.us/i/1001550v.jpg/)


Thanks

[tufcj]

The top flexplate is from a TF727, the second is from a TH400. It's hard to say what engine they were behind.

The 360 and 304 balance is close, since they use the same crank and rods. The bigger bore of the 360 makes the pistons slightly heavier so the balance is different. I've seen some people get away swapping flywheels, some vibrate.

The flywheel from a 6 cylinder is the same, but zero balanced, it will bolt onto a V-8, but will really vibrate.

Sorry I can't be of much help.

Bob
tufcj

[LanceM]

So the flywheels off a 258 :shock: I've ran this behind my 304 for like 5 years :mrgreen: Guess i was one of the lucky ones :t:


Thanks

[Old Rugged Crosser]

Lance:

How did you post those nice pictures? I tried to do that last night but was unable to make it happen. I know this is off the subject at hand but I need to know. Would you be so kind to let me know?

Old Rugged Crosser

[tufcj]

You can't post directly. Go to a free service like Photobucket (the one I use) or Imageshack, and upload your pictures there. Once you load them, they provide direct image links that you can cut/paste into your message.

Bob
tufcj

[LanceM]

Ya i used http://imageshack.us/

Make sure you click on the Upload Options / Resizing >> And resize it to 640 x 480 so it's not huge :wink:

[Old Rugged Crosser]

Thanx guys for the info. I was able to download the pics and they are at the new idea products section. You can view them there.

Thanx again,

Old Rugged Crosser