Author Topic: Converting 2 point seat belts to three point?  (Read 10997 times)

Michael D.....

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Converting 2 point seat belts to three point?
« on: December 20, 2009, 01:24:11 »
Does anyone have any experience in converting any early 230 sl with two point seat belts to a three point (with shoulder strap).  I don't want a to do any major modifications to my interior, but if there was a noninvasive way of doing this I would consider.  I worry about the young ones ridding with me.

Garry

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Re: Converting 2 point seat belts to three point?
« Reply #1 on: December 20, 2009, 05:42:14 »
There has been quite a bit of past discussion on the subject.

Here are two links re three point belts but the easiest way is to just put in 'seatbelt' in the search engine at the upper right.

http://www.sl113.org/forums/index.php?topic=2484.0
http://www.sl113.org/wiki/uploads/Interior/SeatBeltInstallation.pdf

Garry Marks
Melbourne/ Kyneton, Brisbane. Australia
1969 MB 280SL 5 speed RHD SOLD.
1965 MB 230SL Auto RHD Lt Blue 334G, Top 350H, 213 Leather, Tourist Delivery.
1972 MB 280CE Auto RHD 906G Blue Grey
2005 MB A200.
2006 MB B200
2019 Izuzu DMax 4x4 with Slide-on camper.
2022 Volvo XC40 Twin Electric

mdsalemi

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Re: Converting 2 point seat belts to three point?
« Reply #2 on: December 20, 2009, 18:54:20 »
MichaelD.

It's invasive.  Cutting, drilling and welding.  FYI.
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
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Garry

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Re: Converting 2 point seat belts to three point?
« Reply #3 on: December 20, 2009, 21:45:22 »
I agree with Michael, it can be invasive (but unseen) if you are going with the hidden retractable belt roller.  However, depending on how tall you are, it can be done without any cutting, welding or drilling by fitting the belt retractable roller behind the seat onto the existing belt fixing point.   I am not sure about US cars but my car already had the sholder fixing point as delivered.

You will lose seat travel by several inches so your height becomes the telling point.
Garry Marks
Melbourne/ Kyneton, Brisbane. Australia
1969 MB 280SL 5 speed RHD SOLD.
1965 MB 230SL Auto RHD Lt Blue 334G, Top 350H, 213 Leather, Tourist Delivery.
1972 MB 280CE Auto RHD 906G Blue Grey
2005 MB A200.
2006 MB B200
2019 Izuzu DMax 4x4 with Slide-on camper.
2022 Volvo XC40 Twin Electric

jameshoward

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Re: Converting 2 point seat belts to three point?
« Reply #4 on: December 20, 2009, 21:51:50 »
MichaelD,

It may be invasive for an early 230 as Michael has said, but for a late 230 (Nov 66) it's a relative piece of cake with no welding at all or cutting of anything more than the cosmetic plate at the B pillar, and a little drilling. All the relevant holes are present to convert to a 3 point seatbelt on the late 230. I did mine in about half a day from start to finish and whilst I didn't do a perfect job cosmetically, it's perfectly safe (has passed the German TUV and UK MOT (annual safety checks for older vehicles) without a problem) and far safer than a lap belt. My car is a US import.

There's a merc bulletin on how to do this that some kind forum member sent me. PM me for details, but please note that there may be differences between early and late 230s, which is what I think Michael S is getting at.

Moreover, there are different ways of doing this. As a tall fellow I opted to put the reel in the area under the parcel shelves (as shown on the Mercedes bulletin) but others - like Garry's car it seems - have taken a different route. There's no loss of leg room doing it in accordance with the Merc procedure as I recall.

I wouldn't hesitate to make the switch for the obvious safety benefit. Do a search and you'll find a good deal of info. Read all that first.

JH
James Howard
1966 LHD 230SL

scoot

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Re: Converting 2 point seat belts to three point?
« Reply #5 on: December 21, 2009, 16:12:37 »
If you convert to 3 point STATIC belts (Kangol for instance) I thought there was nothing that had to be done and that the proper anchors are already present.  Is this not the case?  I realize that for retracting belts that lots of other stuff needs to be done so I'm not talking about retracting belts.
Scott Allen
'67 250 SL (early)
Altadena, California

jameshoward

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Re: Converting 2 point seat belts to three point?
« Reply #6 on: December 21, 2009, 17:06:14 »
Scoot,

I'm talking about retracting belts, for which there is actually little to do. On my car, I could have fitted non-retracting belts more easily, that is correct. There is a little cutting of the B pillar cosmetic panel that's required for fitting retracting belts. It's easy enough.

JH
James Howard
1966 LHD 230SL

scoot

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Re: Converting 2 point seat belts to three point?
« Reply #7 on: December 21, 2009, 20:42:50 »
James - yes, but it is not clear if the OP is wanting retracting belts or static belts...
Scott Allen
'67 250 SL (early)
Altadena, California

jameshoward

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Re: Converting 2 point seat belts to three point?
« Reply #8 on: December 21, 2009, 22:49:57 »
Scoot - my point is that it doesn't matter. Both are easily done with the more simple operation being a harness and the slightly more complex being a retractor!  ::)
James Howard
1966 LHD 230SL

scoot

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Re: Converting 2 point seat belts to three point?
« Reply #9 on: December 21, 2009, 23:55:41 »
I guess I thought that drilling and welding were more complicated than snipping a whole in vinyl and using the shoulder anchor point that is already in the car...
Scott Allen
'67 250 SL (early)
Altadena, California

jameshoward

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Re: Converting 2 point seat belts to three point?
« Reply #10 on: December 22, 2009, 08:33:44 »
It may be invasive for an early 230 as Michael has said, but for a late 230 (Nov 66) it's a relative piece of cake with no welding at all or cutting of anything more than the cosmetic plate at the B pillar, and a little drilling. All the relevant holes are present to convert to a 3 point seatbelt on the late 230.
???

It's easy. No welding, drill 2 holes, cut a little bit of metal.

The car is so much safer with the job done. Go for it!

JH
James Howard
1966 LHD 230SL

Dave Gallon

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Re: Converting 2 point seat belts to three point?
« Reply #11 on: January 17, 2010, 10:01:26 »
At the risk of being pummeled with stones - what is unsafe about static 3-point belts? I have driven my 280SL with Kangol belts over 100,000 miles and fintails with Kangol belts more like 200,000 miles. If you have to cut metal and drill holes, it may not be difficult but it is a modification I am unwilling to make. It is obviously more difficult than threading a bolt into an existing hole. I do understand that many consider it more convenient and / or more comfortable. In my specific case, I can easily reach and operate all dash controls with the Kangol belt nice and tight. I submit that without an automatic tensioning system (identified by SRS label) such as is present in any Mercedes since the mid-1980s, a retractable belt will rarely lock tightly enough to be as safe as a static belt.
Dave Gallon
Gallon Restorations
113.044-12-001155

mdsalemi

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Re: Converting 2 point seat belts to three point?
« Reply #12 on: January 17, 2010, 16:16:01 »
At the risk of being pummeled with stones -

Dave--nobody will pummel you with stones.  The installation of retractable 3-point seat belts, done properly (e.g. such as that following the MB Tech Bulletin, or perhaps that done by talented and skilled craftsmen) provide a modern feel and convenience you simply don't get with the static Kangols.  It is an invasive procedure according to the directions, but somewhat less so when your car is all apart anyway.  I never used the 3-point static Kangols in my car but had them in some old British cars, and found them rather annoying; difficult to adjust and not up to my particular needs.  Others might find them a joy.

I'm not certain I would take a car in "fair to middling" condition and add them, but for those concerned with safety in the middle of an extensive restoration, it is certainly something to consider--particularly if you are planning on doing some driving and want belts.

There are those that don't like seat belts at all--and those that don't wear helmets on a motorcycle, or safety goggles when using certain tools, etc.  To each their own.  Any safety belt is better than none, particularly if you use them!  ;)
« Last Edit: January 17, 2010, 20:08:06 by mdsalemi »
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2022 Ford Escape Hybrid
2023 Ford Escape Hybrid

hauser

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Re: Converting 2 point seat belts to three point?
« Reply #13 on: January 17, 2010, 17:21:16 »
Here's one installation done on a 113 using a later style MB seat belts.  

http://www.motoringinvestments.com/MainPage.htm

I tried a direct link but unable to.  Go to page 6 to look at the install.
« Last Edit: January 17, 2010, 17:24:38 by hauser »