2013 Super Crew with 6.5’ bed and 3.5 turbo. 160k miles. If I give it enough gas the gear drops I get a terrible shudder. Not if I’m easy on the gas. No engine codes but I just swapped plugs and throttle body with a dealer part.

 

video of sound? i have my thoughts but want to hear it

 

When was the transmission fluid serviced?
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no video just did it yesterday. No noises. Just very jerky. Like it lunges. No CELs. I can take it out later and get a video. All tight under the truck. Feels like wife’s Touareg did when carrier bearing went out but it’s very tight can’t feel any play.

 

I did that and filter at 100k. Maybe 120. Ford fluid.

 

Wiggle the driveshaft and feel for any play. I was originally thinking maybe torque converter

 

so yesterday it drove fine all day. Today I go to start it and nothing. Charger says battery totally flat. Not sure if this is related but charge batt now then check alternator I guess....holy hell.