Debris in Transmission Pan?


Hey Austin,

I am changing the automatic transmission filter in my Ford F150 4.6 V8 and I found this yellow plastic thing inside the transmission pan. What is it?

Hey Donald,

Oh no, not the yellow plastic retaining pin that holds everything together!!!!! Actually that is to help keep the fluid from burping back up through the dipstick tube. Just push it back into the dipstick hole and you should be good to go. In case you are unaware, that round ring stuck to the bottom of the transmission pan (upper left portion of your picture) is a magnet to catch all the metal shavings and debris that is wearing off inside the transmission.

Picture 206

Don’t be too alarmed if you can pick off a 2 finger pinch of metal filings from the magnet…that is pretty much normal wear and tear. I have seen bits and chunks of plastic and metal in the bottom of some transmission pans….that’s NOT a good sign. Just clean off the magnet, reinstall the plastic burp plug in the dipstick, replace your filter and reuse the Ford hard plastic gasket.

Lucas makes some really good semi synthetic transmission fluids and additives

Austin Davis

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."
  • Julio Rogelio Maria de Camargo

    Y’all are idiots. The transmission was built elsewhere, and didn’t come with the dipstick tube in it. Instead, it came with that yellow plug, which was pushed in by the tube during vehicle assembly.

    Put it back in the tube, and your dipstick will promptly deposit it back in the pan. Its presence indicates that you’re the first one in there.

  • Austin Davis

    Hi there, thanks for your question. I am not a transmission mechanic, so I would encourage you to visit one. There used to be an oring at the base of the dipstick tube, but not real sure if they do that anymore on 2005 and up. What I am concerned with though, is this only happens when you pull your camper. To me this tells me that the transmission is probably overheating and causing the fluid to gulp up into the filler tube.

    Do you have a transmission cooler installed? If not, I would install one. Have you serviced this transmission filter lately? if not, I would consider it unless you have a lot of miles and have other shifting or slipping issues. Maybe use a synthetic oil which tends to run cooler than conventional fluid.

    I am more concerned with the possibility of transmission overheating than the leak.

  • steve meadows

    2005 f150 leaks around transmission dipstick tube only when i pull my camper.stays dry all the rest of the time. is there a o ring there or what. what do i need to do. I am a pretty good mechanic just need to have some good advise