Occasionally, the driver's seat will rock back and forth/up and down. This is especially disconcerting when taking off from a stop. It doesn't seem to be tied to seat location on the track as moving the seat forward and/or backwards doesn't stop it from rocking.

This doesn't happen all the time and seems to go away and come back with no rhyme or reason. Anyone have any ideas on the cause and fix?

 

Are the bolts that hold the seat down tight? I can't really imagine they got loose on their own as they have a loctite type compound on the threads, but first thing I would check. Rust issues in the floor pan maybe?

 

The driver’s seat in one of my 04s does the same thing. Only moves about 1/4” but like yours, it does it no matter where it’s positioned. It not the back or the base, but the whole chair. Something under there must be loose.

 

yeah, the base is tight. no rust.
a little more investigation today and i think it has something to do with the motor that tilts the seat up and down. after i finish cleaning up the downed tree in the back yard i'll dig into it a little bit deeper.

 

that's what i'm thinking. a part connecting to the motor that moves/tips the seat up and down may be loose/broken. it's getting really annoying pulling away from stop signs and lights right now.

 

I had this exact symptom on one of my trucks, took the seat out to diagnose. There was a weld on one of the pin brackets broken loose and the mount was moving.

 

Mine has been doing this so it look like I am not the only one. Have not had time to check.

 

I took the side plastic panel off to get a better look at things. Not really helpful since I'm not sure what I'm looking at anyway. I moved the seat forward/backwards and tilted the front up/down while looking underneath. The only thing I can see is a tube that goes across the seat base spinning when I try to tilt the seat up/down. Well, tried to tilt the front up/down. Only the back of the seat will tilt. The front goes nowhere.

After all that the seat decided it's finished rocking and will no sit rock solid but also won't go as far back as it used to. I'm really confused. And slightly uncomfortable sitting as close to the pedals and steering wheel as I am now.

Guess I'll be pulling the seat at some point to see what's going on under there.

 

My seat does this as well. Looked at the bolts at the base and everything was tight. I was dealing with some more pressing issues at the time so I have been just dealing with it. Probably take a look at it on my weekend. Curious to see what your issue is. GL

 

Similar issue on a P38. Interested to see what you find/discover.