440 flexplate/ torgue converter info

1969dodgedart

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Looking for some info on flexplate vs torque converter combinations. Presently have a B&M 10237 flexplate married to a 3000 stall converter, 440 has cast crank ( rotating assembly has been balanced) as well as 727 has been rebuilt. Getting a vibration in reverse/ forward that follows rpm 1000- 3000. When I see the moon shaped piece out of the flexplate and no weights on converter can't help but think thats the issue?
 

GTX JOHN

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You have the wrong flexplate = It is for an external balanced converter.
Theer are several different ones.

IF your engine is NOW internally balanced you need a full round neutral
flexplate and a neutral balanced dampener!

Pronto!

Before you wipe out the thrust on the crank and the front
pump on the transmission.
 

doug 371

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the moon shape is so you don't need converter weights. If the converter does have weights by chance they will be at the opposite of the moon
 

Max1196

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10237 Plate, cast crank, balanced as a unit, No visible weights on the convertor, harmonic balancer is an external use unit? Describe what you see for a balancer, and report back.
20221106_151420.jpg
 

1969dodgedart

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No visible weights on converter, externally motor balanced with Performance Products harmonic super damper balancer that was balanced with rotating assembly.
 

33IMP

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Step one is to find out if it's an engine vibration, or a driveline vibration.
If it vibrates in neutral on the driveway, it's engine related. (or flexplate/converter).
 

33IMP

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Next test: find an isolated road, run it up till it shakes, kick it into neutral, and kill the motor. If it's still vibrating......? Further investigation to do, but it ain't the engine!
 

1969dodgedart

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Did some testing: took v belts off ran the engine up / down still feel the vibration( alternator pulley looks a little wonky so will check the run out on that next weekend),ran it down the road and vibration is there following engine rpm after I put v belts back on .. ran the engine up/ down in P / N still feel vibration in the steering wheel and in the floor at ur feet. Pulled the crank pulley to recheck the harmonic balancer had the proper weight installed , which it does . Next plan of attack is to pull 727 and check TC / trans / flexplate.
 
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