A how-to for headrest rails

[lurtch]

Hello to All,

As we all know many of our SL's were not equipped with head restraints. Such is the case with my 230SL.

I live in the so-called Silicon Valley where the traffic flow is intense no matter when you are on the road. This correlates with a high likelihood that I might one day be rear-ended by some lame-brained teenage girl fiddling with her cell phone. Probable result: debilitating whiplash neck injury.  - - - NO THANKS !  

Therefore,  my in-process interior refurbishment will incorporate adding  the headrests to my seat backs.

There a several sites on the web that describe a procedure for retrofitting headrests into the  seat-backs. However, most of them have poor photos and incomplete descriptions. A search of sl113.com produced lots of results but not any specific work instructions.  I will walk you through the steps of how I recently did  it.

I was able to procure the four recievers and also the headrest assemblies quite simply, by just being patient and checking on eBay every couple of days. They did eventually turn up there. The necessary "notched"  (later-style)  seat back cushions are also easily found, but are kind of expensive when bought from a vendor. ( US $110.  to $180. each )


Near the top end of each  receiver ( or rail , as they are commonly called ) is a 10 mm  peg with a groove in it . The Mercedes design consisted of a keyhole slot in the sheet metal seat frame for the groove to engage as the peg slides down . No other retention method was used, other than the two sheet metal  screws at the lower ends .

The usual retrofit would require cutting narrow precision width slots in thin heat treated steel while it is oil-canning. This is not an easy task even for someone like me who has an FAA Airframe license. There IS a better way - -


Since the piece of sheet metal across the top of the seat back frame is too flimsy anyway,
I first pop-riveted on an aluminium doubler  plate (.035) to reinforce the area.

After a precise layout with the pieces assembled, I then drilled  two 10mm through holes.
 
My method of attachment for the peg is to use an "e" clip. Before passing the peg up through the hole, I selected a thin grommet to shim up the height difference and  provide a  compressive type of fit for the e-clip to seat against.

An alternate method uses a crimp-able type retainer. The malleable C_clip from a brake shoe overhaul parts kit works quite handily.

The lower end of the rails is secured with s/m screws in the conventional M/B fashion.  My upholstery shop is handling the installation of the new leather seat covers.  
 
My finished product photo shows the new back cushion, the Maroon leather, and the C_clip detail.

I encourage everyone to consider this important safety enhancement.

Regards to all, Larry in CA






Download Attachment: doubler-attachment.jpg
63.44 KB

Download Attachment: hole-locations.jpg
65.57 KB

Download Attachment: e_clip.jpg
10.87 KB

Download Attachment: off-to-the-upholsterer.jpg
65.38 KB

Download Attachment: finished-product.jpg
54.11 KB

[Longtooth]

Larry --- good recommendation... very nicely done & well documented.  I think, however, it detracts from the original lines especially when the top's down.  If you're not an originality nut (like me) then adding the later head-rests to a 250SL or 230SL is a good move from a potential safety point of view.  I might add though that my son was rear-ended in a 70 VW bug (front seats had the built-in extended head-rests)... and the seat tore off it's mounts... engine ended where back seat had been, and my son's knees were stuck under the dash with hinge having broken so he was laying as near prone as the back-seat being pushed forward would allow.... very slight, non-lasting neck injury to my son.... he wore a neck brace for a week (just to insure no added strain while neck and shoulder muscles recovered).      

About the likely hood of being rear-ended while driving in Silicon Valley and environs. I differ with your assessment.  I've lived & driven here since '64... I've communted to work daily from '70 until I retired a few months ago. I've rear-ended 2 other cars in that time (one at only 2 mph, the other at 30-35 mph... totaled my car (a BMW), hardly scratched the other one, nor was the occupant of the other car injured --- a Honda Accord)... and I've never been rear-ended nor has my wife.  I admit the traffic is heavy with lots of speed-up then stop on dime type driving on the conjested freeway's here.  But odds are that you won't be rear-ended.... based on the odds I've experienced (me, my wife, my son, my daughter, my daughter-in-law) here in over 40 years of communting (me)... and I'm an agressive type driver (though I drive defensively). That's roughly 105 people years of daily driving to date, (giving my wife only 20 years of equivalent full year driving over 40 years) with 1 rear-ender occurred to us. Statistically, the odds are you won't be rear-ended in your lifetime while driving your pagoda. KNOCK ON WOOD!

[psmith]

Hi Larry,

Great write up.  My car has the headrests but one of them is floppy so when I get to fixing it, I'll check back here.  I think it's a good candidate for the Tech manual.  Headrests and 3 point seatbelts were both requirements from my wife.

[Peter van Es]

Larry,

thanks for this helpful write-up. Why didn't you put it straight into the Technical Manual? Scroll to the bottom of the page. There's been a place holder for "Adding headrests to a 230SL" there waiting for your article.

It really isn't all that hard.

Peter