Thread: Sounded like a cracked flexplate, but it looks perfectly fine.

I had what sounded like a broken flexplate (a rattling, metallic sound at idle that quieted down/went away with the application of throttle), but I have my transmission out of the car and the flexplate looks to still be intact. What else could cause something like this. I noticed that the input shaft of my trans has a lot more in/out play in it than the one I'm planning on putting in. Also, I was able to push the torque converter side to side (like checking for a bad wheel bearing) and it seemed to move a good, noticeable amount.

I'd like to get this thing put back in the car tonight, so any and all information/suggestions welcome.

rod knock? oil pump finally building pressure at higher rpm? you have an oil pressure gauge?

No rod knock, 50 psi of pressure at idle. It's definitely in the transmission. It would get louder in gear and quite down in neutral/park.

send a blank check to dave.....

Thanks for the advice?... If I had the money to do so, I'd definitely be doing that.

Another problem has reared its ugly head. 5 of the flexplate to crankshaft bolts sheared off upon removal. I looked at the shear zones of each bolt, and it appears that two of them had been cracked and nearly broken for a long time prior to removal, and the others had small cracks before removal. I suppose I may have over-torqued them when I re-assembled the engine last year?

Anyway, I'm working on drilling the bolts out and re-tapping the holes. It's a slow, delicate process. I have only one of the holes drilled out, but ran into some problems with the cheap-o tap my roommate has. Bought a new set at work today and will have all day tomorrow to (hopefully) finish the drilling/tapping process so I can get the trans back in by tomorrow night.

I bought new ones when I did the build.

fwiw, my 2750 torque converter was going bad and was making sounds exactly like a broken flexplate when my flexplate was 100% fine.

Originally Posted by skidoojames151

i dont think the flexplate bolts are re-usable, thus your broblem

they arent because they are TTY, but when was the last time you didnt reuse a bolt because it was in the motor once already? i have reused crank bolts and not cared.

i didnt reuse flexplate bolts.