Dear All,

I'm in the middle of trying to fix a wonky driver's seat on my 1981 W123 300D.

Over all the seat in pretty good condition, however, the back isn't reclined evenly. The inner side of the seat is slightly more reclined than the outer side of the seat. (See photo)



So I've removed the front seat. To do this you need to raise and lower the seat and push it backwards and forwards in order to gain access to the bolts on the end of the seat rails. Then lift the rather heavy seat out.

To separate the seat back from the seat bottom I found that you need to remove the plastic trim (or move it out of the way) on either side of the seat.





Once you've got the plastic trim off you need to remove the (four) 13mm bolts and push the top of the seat forward (this will help anyway) to separate the seat into its two main parts.

The adjusting knob is also a simple plastic push fit - see photo

I'm always a bit nervous doing this sort of thing as the plastic trim is held in place by an integral (plastic) bayonet type molding that is really easy to break. Take it easy - but the only way to get it off is to lever and pull!

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I'm now figuring out how to re-align the seat adjustment. I'll post some more stuff when I've got that far.

Right I got the back cover off of the seat back and I've found that there is no way of adjusting the mechanism - well no easy way as it consists of two sealed riveted units connected by a square rod. It seems that the only way to adjust my slanting seat is to do it via the connection to the seat base...

Anyway here are some shots of the seat with the back removed. To get this far you need to remove two self tapping screws from the bottom of the seat back. The side pieces of the back then sort of clip and slide out - there is a lug about half way along the length that helps with location.



Here are some shots of the adjusting mechanism within...

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Well it was a good chance to clean up the seat and apply some Lexol on all of the leather bits - I'm now gonna put it all back together and re-jig the holes so the seat back is equally aligned on both sides.

It's been a long time since I had a W123 seat apart but on the W114's the adjusting mechanism is bolted to the upper seat side arms. You undo the mechanism from one side, slide it off the rod and re-install in the proper position. They usually slip a cog when someone has the seat fully reclined and applies excessive weight to the upper portion. Pull the top seat cover, adjust the mechanism and replace the covers.

Check for broken springs on the seat bottom. Quite common on the W123's especially on the outer edges.

Thanks for the link Army...
Finally got mine sorted out and replaced!!!

Sorry to hear about your unfixable mechanism.....

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Thanks for the tips Mike D - everything else seemed to be OK

After playing about with the seat back and the base of the seat I got the two sections to line up correctly.

Unfortunately when I put the seat back in the car the seat was still a bit wonky. I can only assume that the repair job to the sills is not straight. To compensate I've jacked up the inner rear mount by a height of 1cm with some washers. The seat is now straight.