I just put my engine together and I'm getting a horrible vibration. Almost like when I had my V6 2.8 with a T-5 and didn't have a pilot bearing in the crank.

I just completed a 357 swap. Started it up and I'm getting a crazy vibration around 1k rpms, my idle at the moment. When I was installing my 700R$ I did notice a PILOT BEARING installed but didn't think I'd have to remove it.

Is this the cause of my vibration? Thanks for any help!!

 

No pilot bearing or bushing used on an auto, look elsewhere for the vibration!
flexplate or trans internal?

 

Pilot bearings are only needed with a manual transmission. It supports the end of the input shaft. Automatic transmissions have a torque converter bolted to the flexplate. A pilot bearing isn't required and it doesn't matter if it's still in the back of the crank or not.

 

That's not what I wanted to hear

Well guess next would be flex plate? Could have the engine off balance probably?

 

That would be my first guess. Different bore meaning none stock components. Was the rotating assembly balanced before it was assembled?

 

I do know it was bored .40 over. So . So over sized pistons, and that's it. And yes I believe it was. The vibration feels right at the flex plate exactly. Right in the mid section of the car.

 

Fixed it. It was a warped flex plate. To be on the safe side I'm going to go ahead and pull the pilot bearing.

 

There's no pilot bearing in an automatic. The torque convertor has a stub machined on the side facing the engine and the crank has an appropriate sized hole to accept the stub.
.825" stub for most V6 applications. 1.703" for V8's and 90* V6's.
No bearing or insert.

 

Yeah It's even possible that with that pilot bearing being in there originally, and me forcing the TC on it, may have warped it.

I'll keep you guys informed.