I had a TC bolt back out sitting in the case/adapter hitting the flex plate, fixed that. Used red loctite on everything, all bolts are tight, billet goerened flexplate installed. Still getting a rattling sound when the torque converter is locked under load. I think the noise is coming from the TC, not the motor, because it only makes noise in lock up. Hard acceleration in 1st 2nd and 3rd is noise free. Truck idles fine, no abnormal noise. After doing some reading, some cummins people complain about ATS torque converter rattle and early 7.3s too. Anyone ever heard of this? Converter is a DPC triple disc. Transmission shifts fine, no slipping to my knowledge. @Dynamic?

 

Valvetrain?

Interested in hearing what this could be. I've heard nothing but great things about DPC converters. It'd be nice to be able to slap a gopro under there and go drive and see if it helped pinpoint where the sound could be coming from.

Anyone here use a gopro? and how much are they?

I think they're a few hundred bucks now a days, for something like the gopro hero 4, obviously going up in price for the higher resolution ones. My brother has one and it's definitely a nice to have but I'm not sure I'd buy one just for that.

btw I did some googling of you're issues and I found a lot of complaints about the ATS converter but not a DPC. Apparently people were being told by ATS that it wasn't an issue and they were likely just hearing clutches. One guy said when he tore the trans apart found all sorts of burnt clutches and that was the issue. Obviously don't know how much that applies to your situation so worth note.

Called the experts at Goerend, they want a video of the sound. Then Dave G will call me back with a diagnosis, and if it's the TC I will have Goerend rebuild it.

 

In the meantime, I checked the valvetrain for anything obvious...nothing. And installed my new valve cover finally.

 

Can't go wrong with their converters, mines doing great! 

 

I need to get a valve cover like that! 

It's definitely possible to have a rattle in the converter, but it doesn't happen often. As long as all of the bolts are torqued to specs and you're still getting the noise, it's definitely a possibility. Both Goerend and DPC are top shelf converters. I use a bunch of both, and both stand behind their products like none other...

10 hours ago, Dynamic said:

It's definitely possible to have a rattle in the converter, but it doesn't happen often. As long as all of the bolts are torqued to specs and you're still getting the noise, it's definitely a possibility. Both Goerend and DPC are top shelf converters. I use a bunch of both, and both stand behind their products like none other...

 

I have a bottle of red lubegard on the shelf, is it even worth trying? Currently running just NAPA ATF+4

Edited June 24, 20177 yr by CTcummins24V

Finally solved, a day before I sold it!

 

front axle, intermediate shaft bushing was all worn out. With the CAD removed, I could lift both the intermediate and right outer shaft 1/4”, so both shafts, shift fork and collar were rattling hard with the torque converter locked.  Noise would disappear in 4 Wheel Dr. 

I had a rattle I swore came from the transmission..

Checked tourqe converter bolts. Good there.

 

Turns out it was my rear axle.

I'm making quite a bit of power so my rattle turned out to be the flex plate was broken.  Something unique to cracked flex plates is the noise they make if you just barely bump the starter.  It's kind of hard to explain but it sounds like a twing or a loud tang noise.

5 hours ago, army_greywolf said:

I'm making quite a bit of power so my rattle turned out to be the flex plate was broken.  Something unique to cracked flex plates is the noise they make if you just barely bump the starter.  It's kind of hard to explain but it sounds like a twing or a loud tang noise.

Is this how they check for cracked wheels on train I wonder, seen a union pacific guy with a hammer walking along the train smaking wheels.

Would make sense. You always want to 'ring' a grinding wheel before putting it on to make sure it's not cracked.

Makes me thing of adjusting big brakes. Had one lock up this week.  

 

I got outa the truck fire exstinsher in hand I didnt have tools to unlock it. Smoked my way through town.  Close to a fire.