Do you have tennis balls in your seat bottom?
 

I seem to remember an enterprising member who posted that he solved his seat sagging problem with a tennis ball installation in the spring section of the seat bottom. My driver's seat is sagging badly to the left and it's bothering the hell out of my back. Can someone either walk me through this or give me a clue where to find this original post? I'm not prepared at this point to dump another $150 plus the cost of a new horseyhair pad into this car yet. I'm still smarting from the last repair. Thanx guys.

First you must find a tennis court with gates wide enough to drive your car through... then you open the door and have someone with a really hard serve go at it... best to cover the small delicate things like the radio switches and the turn signal lever...
I think that was Jabaj007 that did that..but will edit if I find out differently... :D

Yes it was,,, in this thread:
www.panix.com/~rmadison/mercedes.shtml

Why not switch the passenger and driver's seat and let the passenger have a sore back for a while?

You mean swap the bottoms between seats? I suppose I could do that too. The tennis balls sounded rather crafty though!

It's my fanny that's riding on six tennis balls in the coil springs of my seat spring frame. I always liked what Lexus has as far as seat firmness (hard) vs. the Mercedes "float", so tried to firm up the old MB. I replaced the horsehair pad, and took three tennis balls per coil and crammed them in there. Really a tight fit and had to puncture two balls per coil to get them in there. Made a big difference, but next time I've got the seat out for something else, I'll see if I can't do it without puncturing them to firm it up even more.

I have a driver's seat that leans on the left side as well on my 1982 300SD. I removed the seat to see what the situation was. It turns out that one of the coils is broken. I read the posting that stated tennis balls were used to fix/firm up the bottom seat. I tried this fix. I can feel one the tennis balls through the padding. Not too comfortable. This helped some, but I will need to order a seat spring frame to correctly fix the problem.

Removal and re-installation was not that bad at all. The most difficult part of puting the seat back in was lining up the seat belt receptacle assembly to the rail mounted on the drive shaft tunnel.

I don't think it would be worth the effort to switch the seat spring frame from the passenger side to the driver's side.

I have shopped around and it looks like Performance Products has the best price. $192.78 for the Seat Spring Frame P/N 91-009. If anyone has found a better price for a 300SD, I would like to know their source and price.

Also, looking from the bottom, my horsehair pad look to be in good shape. I imagine that it may be a different story after I remove the seat cover.

I got a four pack of kids rubber play balls at Target and stuffed them in when I swapped the passenger seat from my parts car for the drivers seat in the real car. The old seat had four or five broken springs - two had been wired back together already.
The balls are about tennis ball sized and not hard, they are that medium squishy rubber foam stuff. I figure they won't lose their spring as fast as tennis balls might. Put four in, made a big difference, even in the former passenger seat.

found a used seat spring
 

Folks,

I did the tennis ball thing for a while. Better than not having them there.

I don't remember if I found a used seat spring on ebay or at one of the junkyards online, but it was about $40 and in good shape. Replacing it was a bit of a pain, but I managed through it (126 ). Glad to discuss if someone needs pointers.

BTW - in taking the seat apart, one of the broken springs had severed the headrest wiring. Splicing fixed it.

I also found that some of my seat adjustments were not working. It appears that I had 1 motor out and 1 drive cable stripped. I bought a seat frame used with all motors. One rainy day I will replace that also (get to take apart the seat again!).

Chuck

I think I might try this trick sometime. I just don't like that floaty fealing of the seats, and want something firmer.

my 87 420sel driver and passenger power seats both have broken springs. I have an 85 300sd parts car with matching interior. How do u take the seat bottoms off? do i need to remove the entire seat from the car? i'm gonna tackle it this weekend, weather dependent of course!!:P thnx!

pool noodles
 

My rear rests on pool foam noodles. They are collapsable, and firm, and slide in real easy. All I had to do is lift the seat cover up, and not even have to take it off to work on the seat. It has worked great for 12 months, and I am considering putting a few more in to firm it up even more.

I swapped in a set of E320 seats that are much firmer. Here is the thread on it.
http://www.peachparts.com/shopforum/diesel-discussion/209131-new-guy-240td.html

heres a link , worked great on all my 123's
http://www.peachparts.com/Wikka/W123SeatRepair?show_comments=1#comments

Mine seems to be sagging a bit, too, now that you mention it. Maybe I'll try this. I know there are some pool "noodles" lying around in my garage somewhere.