I'm building a 1970 f100. I recently fired up and timed my wicked 306 I built that is backed by a built c4. I noticed a clatter/vibrating kind of noise around 2200 rpm and seems to get louder with acceleration, but goes away at about 2600 rpm. there is no noise at idle other than a nasty lopie cam, but it sounds to me like it is in the bell housing. I had a guy come over who has built several pulling trucks and motors and he thinks its something with the block plate, flex plate, and convertor. if anybody has any suggestions they would be very appreciated!

thanks josh

 

By chance did you have the flexplate re-balanced. Someone added a bit too tall a weight to it?

 

yeah the guy who balanced my rotating assembly said the flexplate wasn't balanced very well and added a little weight

 

It may be a bit too tall. Take the convertor nut access plate off and check to see if you find signs that weight is hitting something.

 

does it sound like a problem in the bell housing? I don't think its a bearing since the longest its ran was for 15 mins without a load and there isn't noise the whole time.

 

alright I will try that. thanks for the advice!

 

378941-S .. Torque Converter Lock Nut-3/8" -24 / These nuts have a nylon insert that locks them in place.

These nuts should not be used more than once, because if they are, they may cause the flexplate to wobble on the converter.

Nuts are the same: C4 - C6 - FX/FMX/MX Cruise-O-Matic / AOD