Seat Renewal/Repair

[Mike K]

As with most of our cars, both of my seats have become very spongy and soft after 44 years (in my car's case).
I've been looking at new front seats, but the cost is insane!
On doing a search, I found this old thread: http://www.sl113.org/forums/index.php?topic=15617.0

I thought it's worth raising this topic again, however I was unable to resurrect the old thread.
Following the advice in the thread, I cut up a pool noodle and inserted it under and behind the springs and around the seat frame bends.

For good measure I had also ordered upholstery springs from here: http://www.amazon.co.uk/gp/product/6040757353?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00
These springs are identical to the existing seat springs. I found no broken springs, it turned out that I didn't need the new springs.

As is also mentioned in the old thread, the real pain in the ass was removing and reinserting the front securing bolt on the driver's seat near the seat adjuster, the original bolt is an M8 X 16mm long.
After struggling with trying to reinsert this bolt for over an hour, I eventually overcame this by using a slightly longer M8 X 20mm bolt which gave me more thread grip and more reach with a flexible ratchet.

The difference this simple pool noodle solution has made to the firmness and seat comfort is unbelievable. It's like having installed new seats!
Once I had worked around the tricky bolt, the whole process from removing the seat to reinstallation took under 30 minutes.

Best,
Mike

[66andBlue]

...
As is also mentioned in the old thread, the real pain in the ass was removing and reinserting the front securing bolt on the driver's seat near the seat adjuster, the original bolt is an M8 X 16mm long.
After struggling with trying to reinsert this bolt for over an hour, I eventually overcame this by using a slightly longer M8 X 20mm bolt which gave me more thread grip and more reach with a flexible ratchet. ....

Actually these bolts are all 20 mm long! see: http://www.sl113.org/wiki/Interior/Seats
And if the rear ones are removed first then the seats can be moved back further and tilted upwards a bit which helps removal.
Before re-installing it helps to clean the nut threads with a M8 or M6 tap.

[Mike K]

Thanks for the input, it's helpful for anyone attempting this to know the correct bolt sizes. Reinstallation was painless using the 20mm bolt & a flexible ratchet.
The bolt I replaced looks identical to one of those in the Tech Manual link, but is 16mm long.

Mike

[66andBlue]

It was Joe (JA17) who pointed out to me that a similar but shorter bolt was used on the short water pump.  It's total length is about 21 mm, the length of the threaded part about 15 mm and the flange is about 1.5mm. What you show could be that shorter water pump bolt. Hang on to it because it is NLA!

[66andBlue]

These N170a M8 bolts with the small head are also available from Authentic Classics:
http://www.authenticclassics.com/Mercedes-N170a-Collar-Bolt-8-x-18-size-p/auth-006098.htm

[Mike K]

Thanks for this Alfred, I've ordered some of these bolts.

Best,
Mike

[RonB]

Allen Head Bolts: It is rather easy to remove and install the front bolts with a allen head long extended on a 3/8 ratchet.

I used the one with a "ball" shaped head. It works at any angle up to approximately 15 degrees.

My source for the whole metric set was from Harbor Freight. I also got the straight set at the same time.

It would be helpful to more info on how to use the pool noodles. Pictures

[Garry]

Ron,

Here are two photos of pool noodle fitted into the underside of the seat.  It is just a standard pool noodle cut to fit.  Some wire it in others just tie it in to the springs.  You will be amazed how much it bolsters the seat edges.

[Coochas]

Interesting to see this thread.  My seats are really mushy and I've been wondering how to fix them up.  I saw the pool noodle thread.  Is the consensus that this is a good way to go??    I've seen replacement cushions on line but they are like 3-400 each!

[Dave H]

What O/D are the noodles ?

[Mike K]

As I mentioned at the start of this thread, I was also looking at new seats, but couldn't believe the cost 
I've done both seats with the pool noodles and the difference is unbelievable, the seats are firm and like new.

All done in under 30 mins. per seat, from seat removal to reinstallation! Thanks and kudos to the originators of this idea!

Mike

[jeblack123]

I used the 3.5" (approx) OD noodle. I also opted for the "no-hole" variety which seemed to be a bit firmer than the ones with the hole down the center.

James

[batman]

I was curious as to why the seats in my 1968 seemed to be so firm - so I took out the drivers seat to look underneath, expecting maybe a pool noodle.

On the basis of viewing Garry's photo of the bottom of his seat - what I found seems to be a fairly professional seat refurb that inserts 2 new large springs (towards the front of the seat) and a new additional support metal bar running across the width of the seat between the 2 new large  springs.

All this provides excellent firmness and comfort.

In case someone wants to opt for more than the "pool noodle" approach to increasing seat support below are a couple of pics to provide a guide.

cheers

[mdsalemi]

Mark, when I had my seat out for self-refurbishment, I had purchased a lot of seat spring material, etc. to try and firm them up. I got the heavy duty stuff too, heavier than what the seats are made of.
I doubled and tripled the springing, added steel support, etc. Yet despite all the work, as soon as I sat down on it outside the car, the front of the seat really bottomed out. There was a limit to the amount of steel I could add here.
The foam "noodle" fills the space where the seat springs curve around, and once this is in there prevents the seat from bottoming out, and provides a damper as it were.

One thing that Alfred had done to his seat was adding the flat steel reinforcement bars, and this was possible because the person doing his seat had the material to do so. I couldn't find it, and the foam noodle accomplished the goal.

[vande17941]

Thanks for the idea.  I tried this method today but zip tied them in. Then I zip tied some foam around a pool noodle and shoved that in the front of the seat.

It improved it greatly, but it still sagged a bit in the middle. So I just started zip tying all the springs together as tight as I could (double the number of zip ties in the photo).

The results are SENSATIONAL.

[mdsalemi]

I tried this method today but zip tied them in. Then I zip tied some foam around a pool noodle and shoved that in the front of the seat.
The results are SENSATIONAL.

I hope you still have your seat out, and it isn't re-installed. The Zip Ties concept is a good one, but unfortunately they will NOT last. The plastic will brittle shortly, and if you happen to jump in the seat quickly or someone a bit more corpulent sits down, they'll break. Put that back in and in a year or two, after some use, you'll begin to find broken zip ties making their way out from under your seat...

A better idea to achieve the same goal would be the metal rings and clips used in [automotive] upholstery. They are not costly, but you do have to get them.  Here are a examples:

http://www.amazon.com/Rings-100-Interior-Install-Covers/dp/B001E1OJ4W
https://www.diyupholsterysupply.com/3-Prong-Clips.html

Keep searching around and you can find all kinds of clips and rings designed to fasten the metal pieces together.

What I had done (and sadly I neglected to take a photo) is where you have zip tied two adjacent sets of springs together, I added a set between the existing ones and used the rings and clips for fastening. Despite all the added steel the pool noodle was the big deal and added the best support.

[vande17941]

nah. I used heavy duty zip ties after I took that picture. Zip ties with a hundred and forty pound limit. Did the same thing on a boat seat that's lasted over 10 years. and if they were to break, no big deal. that car will be in for new upholstery before they do

[thelews]

there is such a thing as stainless steel zip/cable ties.  Google it.

[mdsalemi]

there is such a thing as stainless steel zip/cable ties.  Google it.

That makes WAY more sense, thanks John.

[vande17941]

You can use safety wire, 3/8" Wide zip ties (nylon), whatever you want....either way, it's a cheap ass temp solution until properly rebuilding the seat.