F250 Xsmn squeal

[dw8ite]

I have a 2012 F250 with a six speed automatic transmission. I use this mainly to tow a 14,000 pound fifth wheel. On this trip to Colorado when going downhill I noticed a squeal every time I tried to slow down into third gear. It will squeal until the RPMs drop a few hundred and then it will quit. I know very little about transmissions so I was hoping somebody here could offer some suggestions on what the problem might be and hopefully there is a solution like adding BG oil treatment.
Thank you,
Don

[Skilletface]

Originally Posted by dw8ite

I have a 2012 F250 with a six speed automatic transmission. I use this mainly to tow a 14,000 pound fifth wheel. On this trip to Colorado when going downhill I noticed a squeal every time I tried to slow down into third gear. It will squeal until the RPMs drop a few hundred and then it will quit. I know very little about transmissions so I was hoping somebody here could offer some suggestions on what the problem might be and hopefully there is a solution like adding BG oil treatment.
Thank you,
Don

Not an expert here; I know on my model if accelerator pedal is touched after the transmission down shifts, depending on speed, it will up shift even when in Tow Haul mode or transmission brake is active.