Knocking/Tapping Noise

[country_3030]

This morning my truck started making a slow knocking/tapping sound from the front of the transmission. It started while sitting in the wataburger drive through. After continuing to work it quietened down but is still there. I am not positive it is from the trans but sounded like it when I crawled under it. My thoughts were maybe front pump busted or torque converter. Please help with any insight to problems similar that others have had. I work as a Toyota technician but have not heard a noise like this one before. It does vary with rpm in all gears including park and neutral.

[Trevor]

possibly a bottom end knock like a rod bearing?

[country_3030]

Dismiss this please. I found out the source of the knock after I got off work and got it on a rack. Put the truck up on the rack to listen and it was knocking at about one knock every second until it just started rattling. Strangely enough it was coming from the drives side cat. Guess it is time for headers now that the cats are busted.

[ImportThis]

i been telling you that you need headers!!!