E46Fanatics (http://forum.e46fanatics.com/index.php)
-   E46 Convertible (http://forum.e46fanatics.com/forumdisplay.php?f=106)
-   -   Seat folding problems E46 M3 vert (http://forum.e46fanatics.com/showthread.php?t=965957)

petik 01-16-2013 04:02 PM

Seat folding problems E46 M3 vert
I bought an E46 M3 vert a little over 6 months ago and love it, but just like with any other used car I've had to repair a number of items. I'm nearing the bottom of my list with little annoyances and wanted to see if anyone has seen this before I rip into it exploration-style.

Two issues:

1) The driver seat (primarily, passenger also does this, but it's much less pronounced) has significant give in the hinge that tilts the back of the seat wrt the bottom. This is most obvious when doing some aggressive breaking, you can feel the back of the seat tilting forward slightly and your upper body moves towards the steering wheel. In daily driving it's almost unnoticeable, but it's clearly not intended to be this way. I track cars on the weekends and would definitely not take the car on the track with seats that move like that. I did check the bolts that bolt the seat to the floor and those are fine as well as the rails on which the seat sits. It seems to be in the hinge or some other part. A guide or ideas on what to rip into would be very helpful.

2) The passenger seat used to slide forward when I would lift the folding lever . Now it only folds. I'm not sure if the driver seat was supposed to do the same, but it never has. Is there a way to fix this so the seat will slide again? It doesn't feel like anything is broken - was wondering if I accidentally disabled it somehow.

The seats are power and memory, not heated.

Appreciate any insight into this...

johnrando 01-16-2013 11:45 PM

I don't know much about the seats so my only guess on the passenger one is the obvious, clean out the tracks and make sure nothing is making it stick. I certainly haven't heard anything about disabling it, but that doesn't mean it can't happen.

sgoetz628 01-17-2013 09:18 AM

Just out of curiosity I checked mine, which I have owned since new (my seats are like yours + heated). Neither seat slides forward when I lift the folding lever. However, if the headrest is up, it goes down. Honestly can't remember whether they used to or not, but I wouldn't worry about it too much. There's so much electronics in these cars that they often have brain farts. For example, sometimes my top won't go down with the interior button, so I have to use the door key. Other times it's just the opposite. But yesterday I went to put the top down and nothing - from either control location. Then I closed the top holder compartment (reducing the trunk space), tried opening the top and, of course, the yellow light came on. Opened the trunk holder compartment and, voila, the top went down. If these were new glitches happening, then I'd be worried. But like I said, they've been happening since day one, so I still sleep well at night.

Can't help you with problem #1, other than to say my seat doesn't move/fold in the slightest bit without that folding lever being lifted. Seems like something that needs to be addressed ASAP, meanwhile that's how/where your seatbelt attaches.

E46DrEaMeR 01-17-2013 12:00 PM

given the age of the car I would think the locking mechanism which locks the seat in place is worn! hence the movement! possibly caused by just pushing the seatback into its normal position as opposed to keeping the lever raised till its upright again! (had this on a previous car) the seat will only fold when the lever is raised, the rocker switch by the lever moves the seat forward for better access to the rear! and as pointed out ^^^^ if the headrests are raised they will lower when the lever is raised so they don't hit the dash when folded, hth

petik 01-17-2013 12:05 PM

To clarify the two items I posted:

1) This isn't an issue with sliding forward, it is tilting. I'll take a video and post it later today.

2) I know for a fact this used to work on the passenger seat. You would lift the level on the passenger seat and the seat would fold forward and then slide forward (not electronically, but mechanically). Then when you'd manually fold it back it would also slide back in its original place. A friend of mine has a 330ci from the same year and his works as I described.

E46DrEaMeR 01-17-2013 12:31 PM

I understand and my point was that if the pin that holds the seat in the normal position is worn you will be able to tilt the seat forward slightly due to the wear on the locking pin.
No 2 all I can say is my seats don't slide when the tilt lever is pulled but mine is an 02 but another guy here at work has an 05 and his don't do it either we both have electric seats but not heated so maybe this is the reason the seats have to be full electric to tilt/slide

petik 01-17-2013 01:31 PM

1) good point on the pin. any idea on what the assembly of that looks like? is there a pin on both sides of the hinge, because it feels like the right side of the seat tilts more than left
2) i have the same type of seat as you: electric, but not heated. mine are with memory, not sure if that makes a difference.

I tried taking a video, but it doesn't show very well: http://www.youtube.com/watch?v=DPPAengPG_k

E46DrEaMeR 01-17-2013 02:00 PM

from what I can tell from the vid, I would say its wear on the locking pin!! although you can move the seat a little without lifting the lever I wouldn't call the movement excessive, but yes it would bug me too, going back to the sliding forward bit are you sure you didn't press the rocker switch with the back of your thumb cos I have done this myself and watching the vid looks like it could be possible

sgoetz628 01-17-2013 02:01 PM


Originally Posted by petik (Post 15069961)
1) good point on the pin. any idea on what the assembly of that looks like? is there a pin on both sides of the hinge, because it feels like the right side of the seat tilts more than left
2) i have the same type of seat as you: electric, but not heated. mine are with memory, not sure if that makes a difference.

I tried taking a video, but it doesn't show very well: http://www.youtube.com/watch?v=DPPAengPG_k

When you talk about "moving forward" and you said mechanically, do you mean 1) it slides, as though it were spring loaded, or 2) the motor automatically moves it forward, just like when you press the button?

Mine may or may not have moved forward like #2, I just don't remember. But it never moved forward like #1.

And I tested the play in my seats again. Virtually none in the drivers seat, absolutely none in the passenger seat. In an accident, with any play at all, a seatback will gain significant momentum and possibly break right through the latch. I really don't know what the chances are, but I do know that automatic seatbelt tensioners are designed specifically to minimize that momentum.

petik 01-17-2013 02:12 PM

OK, so locking pin it is...any idea on how to service it? I'm really comfortable under the hood, but interior and body just aren't my thing..

For the "moving forward" question, it was most definitely #1, sliding as though it were spring loaded. I am 100% positive it did this. I even had it reaffirmed by some co-workers I was driving to lunch who commented on how the seat used to be able to do this and now it can't, without me bringing it up. I was also able to confirm the feature on a friend's 330 of the same year which also has electric seats.

To add to the accident comment, since the seatbelts and their tensioners are built into the seat on the vert, you essentially get trapped in the broke seat if the locking pin were to break...

E46DrEaMeR 01-17-2013 02:19 PM

I meant as if you pressed the button, I don't think it would slide as in spring loaded cos the motor that slides the seat back and forth has a gear on a toothed runner which moves the seat ergo the motor would drag making it slide slowly if that makes any sense

petik 01-17-2013 02:24 PM

OK, yeah. When I would lift the lever, the seat would tilt and then slide forward mechanically/spring loaded. Pressing the buttons by the lever, the seat would slide electronically/by motor.

E46DrEaMeR 01-17-2013 02:27 PM

as far as replacing a part ie the pin this is the only thing I can find on the seat that might help locate it



petik 01-17-2013 02:32 PM

Yeah, i saw that on realoem as well, but it really doesn't show where the cable from the lever hooks up. I have a bad feeling i'm going to have to pull the seat out and rip into it.

E46DrEaMeR 01-17-2013 02:36 PM

I didn't want to say that but I think you might........tilt the seat and have a look in the area where it locks that might give you some hints, sorry I cant be more help

petik 01-17-2013 02:39 PM

No worries, I appreciate the collaboration. I am a little surprised this isn't a common issue. Maybe the previous owner was a BIG guy :)

sgoetz628 01-17-2013 02:50 PM


Originally Posted by E46DrEaMeR (Post 15070127)
I meant as if you pressed the button, I don't think it would slide as in spring loaded cos the motor that slides the seat back and forth has a gear on a toothed runner which moves the seat ergo the motor would drag making it slide slowly if that makes any sense

That's what I was thinking, so I don't see how a seat could move via the motor or hand-pushed. And, it has that (second) button up top for "express" moving. But... I'm not going to question anybody's memory 'cepting my own.

What's way more important, though, is making sure the latch works properly.

petik 03-31-2013 08:00 PM

Found the problem!
OK, so I finally got fed up with this enough to pull the driver seat (the problem one). I unbolted all sorts of things until I found the problem. Here are pics of getting to the part that actually matters. You only need to worry about the driver side of this seat to get to where the problem is - although I ended up pulling the entire passenger side off too.

First, pull the seat, no pics of that, but there are 5 bolts - 2 in front and 3 in back. Tilt the seat and unplug the harness. Remove the seat.

Past here nearly all bolts are torx, so have your torx set handy. I think I used 3 different sizes.

Put the seat on its passenger (right) side and remove the power controls. There are clips from the bottom. When undone, the whole thing can be tilted up and then the controls can be unplugged and removed.


Unbolt the controls panel and remove it.


Remove the rear hinge cover now that the panel covering it is gone. There is a small torx on the back of it and it comes off.

This is what the side looks like with those things removed.


At this point I put the seat back up on it's rails and started moving it around to see what had the most slack. What I noticed was that the driver side wobbled a lot more than passenger side. I noticed it was the hinged that's spring loaded to balance the seat bottom.

To get a better look and necessary access, I unbolted the front brackets that attach the seat to all the mechanisms below.


This finally gave me enough access to pull the bolt and inspect the hinge. This side appears to have a bushing, where as the passenger side doesn't - not sure why.


To separate the hinge, I had to remove the spring that holds it from inside.

You can see it on the right still in place.


And removed and hinge separated.


Now here's the weird thing. They used a rubber bushing similar to a RTAB or diff mount just much smaller. It APPEARS to be eccentric, but to me that looks just to be how it wore out.


The sleeve on the inside was barely holding in and I was able to pull it out with my fingers.


I tried using a c-clamp and some sockets to try to press the rest of the bushing out but I couldn't get it to budge, so I took a hacksaw and cut the bushing in a couple of places and chipped it out.


Alright, so I figured out the problem - and I bet a lot of convertible bimmers have this (possibly coupes, too, if the setup is the same).

The issue is that I cannot for the life of me find the part to replace it with. RealOEM does not list any of this and I haven't gone to the stealership yet. I'm considering ordering a custom size delrin bushing kit or just making one out of a block of delrin myself.

The sizes are as follows:

Bushing OD 23mm. The housing is about 16mm long.
Sleeve OD 13mm. Sleeve is about 19mm long.
Sleeve ID is 10mm. This is easy since I can probably just reuse the sleeve after I clean it up.

Big question, does anyone know if this bushing can be sourced or know of a place where you can order bushings by the size?

dknightd 04-01-2013 10:29 AM

Thanks for the followup. I wish I could help you with getting a replacement part. If you do find a solution, please let us know :cheers:

sgoetz628 04-01-2013 10:58 AM

Wow, great report on this! Seems to me the easiest and probably cheapest thing would be to get the part from the dealer. Even at their prices, how much could it cost? At the very least, I would call the dealer and ask. Secondly, visit them. Third, make your own.

And if you speak to them, maybe you could ask if the seat slides forward when you raise the seat release lever. Really curious about this, as the memory has failed. Again!

All times are GMT -5. The time now is 02:06 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use