unixadm

I've got a little over 2k miles on my 2018 F150. It's a 3.5L Ecoboost 4WD, 10 Speed, 3.55 Rear with FX4 package. First I have a transmission that does shift pretty harshly at times, especially when cold. I've swapped wheels/tires to confirm the issue is not related to the wheel/tire package.

My issue occurs when driving normally and slowing down. When the truck approaches 25 MPH while decelerating, I start to feel a vibration or shudder from the back of the truck. It feels like it's driveline related. It's pretty consistent in that it does it pretty much every time. I've noticed that if I shift the truck into N before starting to slow down, the truck will come to a stop with no vibration or shudder.

So best I can tell, it's something to do with the transmission/driveline/u-joints/angles. Truck is stock other than a set of Bilstein 5100 shocks on the rear. It did this with the stock shocks as well. I also swapped over to a set of 2018 Sport wheels (instead of the SE wheels my truck came with) and the tires are Michelin LTX MS2's. The truck has no vibration when driving normally or at highway speeds. If I punch it from a stop, the axle does wrap and I can feel some shudder/vibration from the rear, but in normal driving, it's very smooth.

My transmission shifts like crap and my truck was built after the TSB cut-off, so my first attempt at getting the calibrations updated wasn't successful. I think this might be something more mechanical in nature, such as the leaf springs, a bad u-joint or a combination of things.

If you have any experience with this issue, I'd appreciate hearing from you.

Wicked ace

I'll speak to the transmission only. I think you have become a hypochondriac from reading too many posts. At 2000 miles you don't have enough time in to know if you are having issues. Just drive normally, as in smoothly, not trying to induce problems. If it still feels rough by the time you get to 5000 miles try doing a reset by lifting the negative lead from the battery for about ten minutes. Don't try shorting the leads or anything else. Then reconnect it, set the drive mode you prefer and drive SMOOOthly and consistently from then on. You won't even recall having an issue.

unixadm

No offense, this has nothing to do with this forum. This transmission often shifts worse than what I had in my old 2016 Tacoma, so that’s saying something. I used IDS to reset the adaptations. It made little difference. The vibration is what I’m after as that isn’t going away by resetting the PCM.

mbwhite

I'm just recently noticing the same type of issue with my truck. Same specs approx 8500 kms. Have you made any progress in figuring this out?

AZ99

My 5.0l 10 spd has a similar vibration. If I go 40 mph + and the trans has shifted to 10th and I then start decel and braking, as soon as it downshifts to 8th it starts vibrating like it has a bad brake rotor. Do the same and shift to N and it stops smooth as can be expected.
Dealers have reprogrammed the trans multiple times and finally said "normal operation" when they could not fix it. I know that is BS as I have driven other same 19's.

Masi1926

May not change a damn thing, but will it do the same thing in different drive modes: Tow/haul or Sport?

AZ99

Mine does it in any mode as soon as it shifts down shifts to 8th. Sport mode rarely lets it upshift to 10th at 40 MPH so it is less noticeable.

unixadm

On my truck, both of those modes eliminate or nearly fully eliminates the shudder, just as shifting into neutral does when coming to a stop.

Flattusmaximus

My 18 5.0 does the same thing. Accelerating 6-8 at low rpms it almost sounds like a bad tire.

same gears 8-6 deceleration it vibrates/shudders as it down shifts in thru those gears only.

I can feel it in the wheel and the brakes. Disappears once in neutral.

Sport Mode and Tow Haul keep the rpm’s up so it’s less noticeable.

rtg

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