Will Posted January 14, 2017 Share Posted January 14, 2017 Got the trans rebuilt and back in the car and she's back on the road. Got a call from my trans guy today and he said he felt a slight vibration right around 2k that concerned him. He was worried there may be a balance issue with the crank and if not addressed would cause pre mature failure down the road. I know for a fact the passenger side header is taping the lower control arm and needs to be massaged in with a hammer. it has the correct flexplate on there but I honestly can't remember if the balancer on it came with it or was off my 402. Or could tit be bad maybe? Have you guys ever heard of any thing this before? He's a very reputable local guy so I don't think he's making it up. Just wanted to throw it out there if anyone has ever heard of something similar. Thanks Quote Link to comment Share on other sites More sharing options...
mrj52 Posted January 15, 2017 Share Posted January 15, 2017 Is your motor a 402 or a 454? New flex plate? Old or new torque converter? Love to help but we need just a little more info on your machine....... 1 Quote Link to comment Share on other sites More sharing options...
Will Posted January 15, 2017 Author Share Posted January 15, 2017 Sorry, the entire drivetrain is new. 454 bored slightly to 468, Continental 9 inch converter, 168 tooth flexplate for 454 BB, Pro Sport Harmonic balancer, and a TH400. Poly mounts all the way around as well. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 15, 2017 Share Posted January 15, 2017 a 454 is externally balanced, the proper balancer and flexplate are a must or it will vibrate Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted January 15, 2017 Share Posted January 15, 2017 Definitely make sure the flex plate is not cracked, you know the usual spot. Quote Link to comment Share on other sites More sharing options...
Will Posted January 15, 2017 Author Share Posted January 15, 2017 Has anyone ever heard of having a balance issue and it only showing at lower rpm's? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 15, 2017 Share Posted January 15, 2017 yep the first thing is to unbolt the torque converter from the flexplate and run the engine to see if it still has the vibration this will eliminate/confirm if it's the torque converter/trans or with-in the engine Quote Link to comment Share on other sites More sharing options...
mrj52 Posted January 15, 2017 Share Posted January 15, 2017 Also check the fan/fan clutch combo, temporarily disconnecting the belts and run the motor. 1 Quote Link to comment Share on other sites More sharing options...
MC-71 Posted January 16, 2017 Share Posted January 16, 2017 Could just be the ends of your cross member that hold your tranny in. The rubbers can be weathered or the tranny guy didn't reinstall them. Carl Quote Link to comment Share on other sites More sharing options...
Will Posted January 18, 2017 Author Share Posted January 18, 2017 Update* through some research realized that the SCAT crank that's in there does not come with a dowel pin for the flywheel. Apparently none of them do. So when I had some starter issues previously and I replaced the flywheel because of some partially chewed teeth I may not have aligned the flywheel properly for the external balance. Gonna back the trans off tomorrow and check. Quote Link to comment Share on other sites More sharing options...
Will Posted January 20, 2017 Author Share Posted January 20, 2017 Turns out the flywheel was out of place and with some repositioning she's now beautifully balanced. Thanks for the help guys. Quote Link to comment Share on other sites More sharing options...
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