I just rebuilt my c4 and put in a new torque converter. When I am driving I can hear a rhythmic clunking from what sounds like the transmission area. Transmission shifts fine but I am hearing a clunking in every gear. Strangely, when I put the car on jacks stands and run thru the gears I hear nothing. So it only appears to clunk under load. When I bolted up the torque converted to the flex plate I was careful to make sure the drain plug lined up with the hole in the flex plate so I don't think thats the issue. The u-joints were fine prior to the rebuild.

Any ideas ?

Thanks

 

Spacer plate/dust cover hitting flywheel?





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Is there supposed to be a spacer plate between a c4 and a 351C ? I didn't take off the flex plate. Don't those go between the flexplate and the block ?

 

There should be one.

Are you saying there isn't one installed?

 

No. And prior to rebuilding the c4 I had no problems.

 

Check your yoke and the bearings at each end of the driveshaft. It could just be that. If you didnt remove the flexplate, the block plate should still be on the engine

 

Ok I looked and there is a block plate. Just didn't remember seeing it. Replacing u-joint at differential. 2 needle bearing were missing. Felt tight but better to replace and rule out that possibility.

 

FYI the clunking is at the speed of the drivetrain and not the speed of the engine. If its not the flex plate or torque converter is there anything internally that could clunk ? Broken pump gear ?