I recently replaced the driver's side seat spring box in my 1984 380SE. Here are some tips in case anybody is interested. I had a donor passenger seat from an 83 300SD that I salvaged the spring box from.

1. Do not disconnect battery or electrical connections till you have removed all the bolts holding the seat down to the chassis. You will need to move the seat back and forth to get at all the bolts.

2. Raise the seat to its highest level in the rear to be able to fit a 10mm socket and ratchet underneath the rails.

3. To remove the seat bottom cover, it helps to first unbolt the seat back from the seat bottom. You have to do this anyway to replace the spring box.

4. To remove the cover, lay the seat bottom with the bottom up and then press the spring down while removing the seat cover. The ends fit into narrow channels and have to be kinda peeled out with the spring pressed down. Start from the back first. I did the entire work by sitting the seat upside down on top of two milk cartons stacked one on top of the other. The height and leverage provided worked great (I was watching TV in the living room while doing all this - so needed a workbench).

5. Remove and set aside the headrest while doing all the work. It gets in the way.

6. The biggest PITA was unscrewing the three screws which hold the seat tracks to the spring box. I had a hefty Philips screwdriver but still they were godawful tight. Finally, I found what worked great was a screwdriver bit and a ratchet.

7. To remove the tracks, you need to move them back and forth to line up the center hole for removing the center screw. Also, when the rear screw is exposed, the front one gets covered by the track. With no power, moving this is impossible. What I did was pull out the cable which comes out of the seat adjustment motor from the donor seat. Then inserted one end of this cable in the seat adjustment gearing (the worm) and chucked the other end into an electric drill. Worked like a dream in moving the tracks back and forth.

8. Finally, I hated the soft seats. So, I cut some length of horse hair from the donor seat and stuck it between the spring flutes to stiffen em. It has been working great - the seat is nice and firm !

Amit Prasad