Early e12 seat rails - similar chassis to..?

Post your E12 technical questions and comments here. Please, no off-topic posts.

Moderators: Mike W., Pierre

Post Reply
User avatar
Lock
Posts: 237
Joined: Sun Oct 04, 2015 1:51 pm
Location: Washington
Contact:

Early e12 seat rails - similar chassis to..?

Post by Lock » Mon Apr 29, 2019 12:15 am

My seats are falling apart. I have some e34 seats and found that although my car is a '79 it has the earlier floorpan with three studs per side and the floor hump, which is not compatible with the e28/e34 seat rails unlike the later (80-81) e12 chassis which have the two boltholes and flat floor.
Does anyone know what other BMW chassis' have the same floorpan and seat rails as early e12s that would interchange? The firstfives FAQ lists the rear seats but not front.
Reason I ask is when I go to aftermarket sites like Corbeau, they tend to list the same rails for e12 as e28, which is only correct for '80-81 and to make sure I'm getting the right part first time I'd just like to order the seats for a chassis that has my earlier style floorpan. e3, e9, e10 maybe?
1979 528i 5-speed conversion G260/6

User avatar
Mike W.
Posts: 2430
Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Re: Early e12 seat rails - similar chassis to..?

Post by Mike W. » Mon Apr 29, 2019 1:00 pm

Are sure both sides are the early style? My '79 had the later style on the drivers side and the early style on the passenger side. Regardless, and it's been a while, it seems like the seats were the same, mounting wise, just that the drivers side had the separate removable base allowing tilting of the seat up and down in either the front or the back. Again, IIRC, the passenger side just used rails mounted to the bottom of the seat. So what would you be mounting the seats to, the base or the floor itself?
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter

toddness
Posts: 55
Joined: Thu Sep 27, 2012 5:55 pm

Re: Early e12 seat rails - similar chassis to..?

Post by toddness » Mon Apr 29, 2019 1:24 pm

I have a 1975 with the passenger seat out. Definitely a different rail system than the driver side. I'll get some pics later this week.

User avatar
Lock
Posts: 237
Joined: Sun Oct 04, 2015 1:51 pm
Location: Washington
Contact:

Re: Early e12 seat rails - similar chassis to..?

Post by Lock » Mon Apr 29, 2019 5:26 pm

Here's some photos - and you're right my passenger side has the raised frame due to no seat tilting option. I was going to tackle that later because it seemed like a huge pain. Can this metal sheeting be cut away, and if so, what's underneath?
You can sort of see in that photo the hump in the middle, where the 3rd pair of center bolts are. It's definitely not flat.
But drivers side is definitely not compatible with e28 rails. And the e34 seats won't bolt onto e28/e12 rails because it's a whole different assembly.
Replacing these seats seems like it will be painful.

Image

Image
1979 528i 5-speed conversion G260/6

User avatar
Lock
Posts: 237
Joined: Sun Oct 04, 2015 1:51 pm
Location: Washington
Contact:

Re: Early e12 seat rails - similar chassis to..?

Post by Lock » Sat May 04, 2019 1:22 am

Hey Mike, ideally I'd mount the seat directly to the floor not the e12 seat mechanism. I was thinking of getting some rectangular steel tubing that's same size as that hump, drill a hole for the floor bolt and drill another hole on the top that matches up with the e34 seat base. Then grind of the middle bolt, and if all the measurements are correct the drivers seat should sit flat and the bolts should all line up.
Todd let me know if you have any pics of what's under the carpet on the passenger side, whether it looks like it comes out easily or not.
I have no idea what's under the carpet on the passenger side but I get the sense it's a base welded into the frame under carpet. I could put the e34 seat in there but it'd be a couple of inches higher than the drivers seat, look weird and the headrest would almost certainly hit the ceiling. I could possibly hack it all away and try and mount to the actual floor, but there's a sealed cavity between the floor and the underside of the car where I'd want to locate bolts so if I destroy that side I could end up with no ability to have a seat there at all.
So e28/e34 seats won't fit easily. Any other e12 seats will all be as wrecked as mine, so I was hoping to get aftermarket seats (rather than rebuild and reupholster my originals) and be done with it.
As I've seen they all list the same rails for e12/e28 so I predict I'll get a seat that just won't fit and I'll have to send it back.
1979 528i 5-speed conversion G260/6

User avatar
maybeillbuyit
Posts: 172
Joined: Mon Feb 17, 2014 12:26 am
Location: Vancouver BC

Re: Early e12 seat rails - similar chassis to..?

Post by maybeillbuyit » Sun May 05, 2019 11:45 am

I've got an early car as well with the humps and different raised thing on the passenger side. My plan for getting rid of my deteriorating e12 seats is to bolt e21 Recaros to the existing e12 seat rails. Lock I realize you already have the e34 seats but maybe its easier to get seats that bolt right to the rails. Just a suggestion.
1977 530i another project
1979 635csi Euro "project"
1987 635csi

User avatar
Lock
Posts: 237
Joined: Sun Oct 04, 2015 1:51 pm
Location: Washington
Contact:

Re: Early e12 seat rails - similar chassis to..?

Post by Lock » Mon May 06, 2019 1:53 am

That is what I"m thinking. The seats are from a e34 parts car so I'm not committed to using them.
What you said it made me think maybe that's what the aftermarket seat makers assume - their seats don't bolt to the floor, rather the existing rails which is an e12/e21/e28 pattern. In which case, then I'll leave the rails there and have comfortable and contoured seats.
1979 528i 5-speed conversion G260/6

User avatar
maybeillbuyit
Posts: 172
Joined: Mon Feb 17, 2014 12:26 am
Location: Vancouver BC

Re: Early e12 seat rails - similar chassis to..?

Post by maybeillbuyit » Thu May 09, 2019 12:30 am

And the Recaros bolt right to the e12 , e24, e28 seat sliders with the standard e21 adapters. Recaros aren't cheap or that plentiful these days but I figure if I get tired of them or want to change to something else the would be easy to sell. I'll be posting some pics in a little while in my project thread. I plan to have them recovered in red vinyl when I get around to dismantling them.
1977 530i another project
1979 635csi Euro "project"
1987 635csi

PatinaBeforePolish
Posts: 208
Joined: Sun Jan 18, 2015 1:22 pm
Location: Baltimore, Md.

Re: Early e12 seat rails - similar chassis to..?

Post by PatinaBeforePolish » Tue May 14, 2019 3:31 pm

Here're your new seats, rails and all!


https://bringatrailer.com/listing/recaro-2/
78 F150
79 528i
81 528i parts car
01 540i
86 944

User avatar
Lock
Posts: 237
Joined: Sun Oct 04, 2015 1:51 pm
Location: Washington
Contact:

Re: Early e12 seat rails - similar chassis to..?

Post by Lock » Wed May 15, 2019 1:26 am

Great catch! The detailed photos are useful.
I'm also considering lending my car to www.plantedtechnology.com for them to take measurements and add an e12 base to their inventory.
1979 528i 5-speed conversion G260/6

PatinaBeforePolish
Posts: 208
Joined: Sun Jan 18, 2015 1:22 pm
Location: Baltimore, Md.

Re: Early e12 seat rails - similar chassis to..?

Post by PatinaBeforePolish » Wed May 15, 2019 8:23 am

Never heard of them until now. Good resource, thanks.
78 F150
79 528i
81 528i parts car
01 540i
86 944

Post Reply