So I just bought a 2020 cpo F150 XLT. 2.7l Ecoboost. It has 21k on it. When I’m accelerating from a stop I feel some sort of studder. It’s not from the engine or the trans.

(and after clearing the programming on the 10 speed with forscan it’s a huge improvement to the way the truck drives in general.)

I did a visual inspection on the shocks and leaf bushings and everything looks ok to my eye.

I would assume that it’s gotta be the shocks. It’s like the whole rear is trying to torque over when accelerating from a stop because if you let the truck roll and really really ease into it it won’t happen.

This reminds me when I had my 99 new edge get when I first bought it at 130k it had the original shocks and the whole rear was just pulling over.

any thoughts or similar experiences, I feel like 21k is really early to be changing shocks.

 

Two-piece driveshaft?

 

Clutch chatter in the rear end?

 

The Drive shaft has at least two Cross joints.
If they go dry of lube and wear, you can experience what you feel.
Consider the following; when you accelerate, torque will try to wrist the rear housing upward.
This can put a steep angle on the rear Cross joint as it turns. If one spot inside the Bearing Cups binds up, it will cause an undesirable physical displacement you might feel.
The same can happen upon braking where the rear housing twists the other direction and can cause the same result..
Here is something to try.
Get a can of Silicone Spray lube and soak the rear Cross Joint. If the lube settles it down enough to feel it, you likely has proven the need to replace both front and rear Cross joints and if two piece shaft, the center as well.
Good luck.

 

I put small lift blocks in the wrong way once and it created a chatter during acceleration.

Just putting it out there in case someone put blocks in at some point.

BTW I had a bad shock at 40k miles.

 

I replaced the shocks with a nice set of Bilsteins and I noticed I feel it more under my seat now rather than in the rear. Gonna lube up the u joints and gonna check the trans mount for excessive play. Wish me luck.

 

So I finally got to pulling the drive shaft and checking everything this morning. Found the ujoint at the slip yoke was covered in grease and it was really stiff. I lubed it up and tapped the ears to loosen it up threw it back in and fixed. Banging and stuttering gone. Time to replace the ujoints.

Doesn't 20k seem early for this??