Long story short, I have a "knock" coming from my bellhousing. Or Im pretty sure thats where its coming from. Ive heard that the splines inside the torque convertor should only turn one way. I can turn the top set of splines both ways with my finger easy.

Backround:160K miles on L76, Mobil 1 5-30 its entire life. At 80K, lifters AND cam changed under warranty. At 156K, cam and lifters changed. Caught it quick. One DOD lobe had started to get wiped. At 160K, changed cam again cause of the knocking. Lifters AND cam look new. Compression test 170s all cylinders. VE on HP Tuners was +10% or lean at all rpms(small cam).

Oil pressure during this time is 60s cold/55ish hot idle in summertime Texas Mobil 10-30(as per HP Tuners scanner). Melling 10295 Copo spring.

I know rod knock sound, it isnt that.

I already bought a new SFI flexplate, havent tried starting it yet. I thought about cranking it without torque converter, but Id rather fix the problem before hand. Hence the testing question. I would have to reinstall the exhaust because cranking without is too loud. Kinda of a b, plus Id have to have trans close since it wont crank without it plugged in(I think).

Any ideas? Or should I just sent it to a torque converter place for testing?

 

being able to turn the top splines both ways in the converter is normal. That is the stator which is sandwiched between 2 bearings and/or thrust washers. the only 1 way thing is referring to the sprag inside the stator that will do its job once it is splined onto the transmission.

I would start by checking to make sure all the bolts on the flexplate and converter are tight. Since its a new SFI flexplate Its probably safe to assume the flexplate isn't cracked.

 

Pull flywheel look for cracks around the mounting bolts that radiate outwards

 

I would start it up without the torque converter bolted to the flex plate. No noise send torque converter off to be tested. If noise is still there you have other problems.

 

Just an idea. I have a 2011 Silverado 5.3 6l80e. I heard a knocking noise coming from the bellhousing also. Starter went bad and the gear was bouncing off the flexplate.