Radiator change seems to have fixed transmission knocking at idle

[holmesnmanny]

My tranny has been knocking at times when at idle and slightly on an incline. I've always thought it was coming from my blown struts but have always thought it was the radiator tranmission fluid compartment that was corroded to the point of preventing fluid movement due to the fact that there are some days when the tranny runs like it's fairly new still so the other day I saw a slight crack at the top of the radiator and figured it was a good time to change it out. Now the knock is almost completely gone, even when I run it hard.

The tranny was simply overheating.

My radiator was oem so this could be good advice to those in the same boat as me. Even if it's not leaking if the thing is really old just change it anyhow.

[Doctor J]

Wow the knock must be produced by tranny pump by pass valve or pump itself.
A quick way to check for the pump noise is to pull on the TV cable at idle and see if the noise increases.