Weirdest shifting truck I ever had. The shuddering you're feeling is from the torque converter. Inserting the dipstick is done by turning it a little as you push it in, make sure you clean it up , free from any rust ,etc. It is designed to be shifting all the time, that's why it has extra gears! The F250 experiences shudder every time it shifts into overdrive; however, it's been doing this for the past three years and the condition hasn't changed or gotten worse but differs depending on whether it's towing or not. So in the future if there is premature failure, it is on record.
I turned the truck around went back down the road, turned around again and re-drove up the route again at the same speed. No slipping and very eager to downshift. This phenomenon was first described to me by an off-road suspension guru when these frames were first put into production. I've read where a few others here experienced the same improvement so it's worth a try. I posted something similair a few days ago. Otherwise, this transmission shifts very smooth.
Then if you can video it. Vehicle has a non-serviceable transmission cooler. I bought a 2010 f-150 with 13,000 on it. If you do take it in, please reply to your post and let me know what they tell you. Buy a recycled 2010 Ford F-150 transmission and save thousands of dollars. And by cause I mean exactly what driver inputs and road conditions cause the vehicle to react abnormally.
Now the shifts are firm and deliberate. Somethings are just different - doesn't necessarily make them wrong. My issue is not nearly as bad as what you are experiencing but mine does shift hard sometimes from 1st to 2nd gear however it has gone away lately. Never had these types of issues when getting warantee work done on my Honda's and Harley's. In the mean time, I just have to keep my fingers crossed in hopes that they can solve the issue.
You bought a truck with a 6 speed transmission. Look for the wiring harness bundle along the top of the compartment, at about one third of the way from the engine and the left side, again facing the van. Or it may just be the way it is. It almost feels like it's lugging a little. But the thumping noise does bother me a little.
I only experienced this twice and it was within the first 10,000 miles. I have only had the truck for 6 months and it has 3800 miles on it. The vibration can be felt under your feet all throughout the truck and then it goes away. Sometimes I take off from the light and it hits from 1st to 2nd and then back to 1st. If it wasn't going to use them, it would be a waste.
If so, find the nearest big hill and run the truck as many times as it takes to replicate the issue. Vehicle has a non-serviceable transmission cooler. I don't know for sure whether I am experiencing the same issues as others here but I do notice at about that rpm the converter locks up and it acts like a standard transmission hence the vibration. I only have 520 miles on the truck. This has happened 2 times, both while on the highway. Sometimes I take off from the light and it hits from 1st to 2nd and then back to 1st. I bought a 2010 f-150 with 13,000 on it.
If you do take it in, please reply to your post and let me know what they tell you. Don't be lazy, save yourself a future headache and lots of dough. You must pull the wiring harness down a little … ,or separate the different bundles, to reveal a yellow cap top which is the tranny dipstick, it's about five+ feet long once you extract it. Only question I have is when towing. Our discount used 2010 Ford F-150 transmissions come directly from a dependable network of modern junk yards. Take the plug out and put your finger in the hole.