I decided to open up the driver seat again and was not quitting until i found a solution to this design flaw of a rocking chair. If not, they were going in the trash for some aftermarkets. It seems this problem spans almost every honda model (civic, accord, fit, crv, element, etc) all over the internet and the only fix is that silly bushing replacement tsb that only lasts a few months before breaking again. replacing parts to fix a design defect will never work or last. My method should last forever in theory, or at least a very long time before retightening is needed. best of all, its simple and requires NO welding.
All you need is a few simple tools like socket wrench, screwdrivers, and flashlight to take apart the seat plastics. The fix requires four large washers, thats it. The whole process should take less than an hour, unless you need to run to home depot for the washers. I found some in the garage and used those. I wont go into all the details of removing the side part of the seat, since the other diys and tsbs already tell you.
Start by removing the height adjustment cover, then the c-clamp, and finally pull out the adjustor. i put my seat to the lowest height position before removing the ****. Next remove the plastic cover around the whole outer side of the chair to expose the brackets. the inner part of the chair touching the center console has no covers, but you need to unbolt the whole chair (4 bolts to the body) and pivot it back against the rear seat cushion to access the brackets on that side. i recommend doing the inner console side bracket first, then reinstalling the chair to the body, and finally doing the outer side braket last. this way both sides are "loaded" the same way and the chair will not be crooked when everything is put back. do not sit on the chair when doing this process.
Basically the primary problem is the height adjustment brackets. secondary problem (which accounts for a very small part of the rocking) is the reclining mechanism. The reclining mechanism only accounts for maybe 1/4 inch of play and cannot be fixed short of replacing the chair with a new one. it is caused by wear and tear and there is no easy way to fix. still, this small amount of play should not be a problem and will be acceptable. the main issue is with the bottom part of the seat where your butt goes. when you have the sides of the chair visible and you push down on the seat, you will see the seat height bracket is VERY loose and this is the reason for the huge amount of rocking action you feel when sitting.
Start by finding one of the height adjustment brackets near the front of the seat. start on the inner console side facing the passenger seat. it has two large gold nuts holding it down. remove the nuts with a socket wrench and you will have this.
next remove the two washers behind the nuts that have the square shape hole in them. then with a large flathead screwdriver, pry out the shiny bracket. be careful not to damage the seatbelt explosive stick near it! under the bracket is another weak bushing type of piece. take that out as well. these are all the things you should have from one side. two nuts, two washers, two bushings, one bracket. the studs on the seat should be empty and have nothing else on them. now, keep the two gold nuts and bracket and throw away everything else. here is a pic showing the parts you removed.
be sure to keep the bracket and two gold nuts! you will need them. now this is what the seat should look like with all that removed.
now you need to go hunt for 4 round metal washers (two per side). it is very important to get the sizing right. it should be about the same thickness as the bracket. the center hole needs to be large enough to fully clear the stud and surrounding metal so that it touches the very back of the seat. if its too thick, the bracket will not mount flush or tighten properly. too thin and the chair will still be loose. you want to simply eliminate the empty space in the back and "push" the bracket up so that it lines up with the stud threads. that way when you tighten the nut, it will make full contact with the bracket and the back of the chair. essentially forming a tight and secure mount between bracket and seat. here is what it looks like with just the new washers put on. notice they sit fully back and clear the middle stud and surrounding metal. the hole can be a bit loose as you can see, and the washer will hang down. this is not a problem so long as you have enough contact for a strong connection. one washer is gold and one is silver because i just found these lying around the garage.
now loosely fit the bracket back on over the washers. ensure that the top of the bracket is lined up with the bottom of the stud threads.
put the gold nuts back on and tighten them hard. they are big, just have at it and go at least 40-50 ft/lbs so they will not go anywhere. its possible over time the bolts can come loose from multiple sitting events. i was in a hurry, but what i shouldve done was put some jb weld between the washers and some red threadlocker (permanent metal bonding) on the nut and stud threads. then there is really no chance of it ever coming loose. but i was in a hurry and at least next time i know what to do if it ever gets loose.
here it is with the new washers in place along with the bracket and tightened gold nuts.
now youre done with the passenger/console side bracket. put the chair back down and bolt it to the car body. be sure the 4 bolts are nice and tight. now you can move to the driver/outer side bracket which is easy to work on with the chair installed. do not try to test rock the chair yet because with only one side done, it will still be loose. remove all the hardware on the other side as before, install the new washers, then put the bracket and nuts back. tighten them up and put back all the surrounding plastic covers. youre done! now the only minor amount of play in the seat should be from moving the top part of the seat back and forth. the lower seat where you sit on should have zero play when moving it up and down. sit on it and enjoy having a new rigid chair that does not move every time you brake or accelerate. i did try the height adjustment **** a few turns and to my surprise, it still works! not sure how, but maybe there is enough slack in the other moving parts to allow some movement. i dont think i caused the brackets to loosen in the process because after a few hight adjustments, i put it back to the low setting and the chair was still rock solid.
overall not a very complicated diy and all you need is a few bucks for washers. be careful when working around the chair because of the nasty black grease! i was careful and still got a few smears on the fabric, which meguiars carpet spray was able to take care of. overall im really happy how it turned out. part of me wanted to keep the stock seats because they absorb vibrations much better than aftermarket (which have a very rough ride due to the rigid metal brackets used for mounting). i hope this helps everyone trying to struggle with this problem. it really is such an easy fix, im surprised it took so long to figure it out. and before anyone asks, i was not able to measure the washer size exactly. but its better if you figure it out on your own because each seat may have different size parts, and mine were a bit too big for the opening but still worked. you can do better. good luck and post here if this helped you out! im driving around tonight to enjoy the awesomeness of a solid driver seat.