Possible knocking from bell housing?

[snacks1358]

Hi there, current issue with the truck is...

There is a knocking sound, seemingly coming from the bell housing.

Background is: I traded a van for the ST, ST ran like crap, changed plugs and wires. Plug on driver side rearmost cyl. broke, shoulders and all. Shop removed threads and installed plug extension. ST now runs well. ST was not knocking when I got it...

However, now it has acquired said knock. I've tracked it to underneath, possibly the bell housing. It's a consistent knock, more frequent with higher RPMs. Sometimes the sound changes depending on the pitch of the truck, fore or aft.

I am wondering if perhaps the transmission dip tube rotted off inside, (if that's even possible), or something of the sort. Or it could be the timing chain?

Stethoscope coming soon in the mail...

Any input is welcomed, I also, will update you fine folks!

Thank you for your time,
Snacks

 

[snacks1358]

I forgot to mention, the other day I started it, NO knock! It was facing slightly uphill but by the time I finished loading it for the dump, it started knocking again... Sitting, idling, never touched the gas...