Replacing the springs with bags is entirely different than putting bags in the springs. My dad put bags in the springs of his Volvo wagon and it made it ride rough even when the bags had no air in them.

On my 95 chevy wagon the bags in the springs made it feel just right with no air....firmer. Of course it was a total floater without them.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

They go under the springs entirely, you can use large flat washers welded together if you have cheap washers lying around. You have to drop the rear to install the spacers but they definitely helped. Needs an alignment after though

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Raising the rear permanently will reduce your effective caster on the front end and make the car less stable in a straight line on the road....unless you get it aligned, and I don't know if there is enough adjustment available to correct for it.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Because I carry about 300 pounds of stuff in the trunk of my '96 Toyota Camry sedan, and also installed a light-duty hitch to let me pull a small utility-trailer, I installed Camry wagon springs & struts in the rear. The rear of my car sits about 2.5 inches higher than it was with the sagging sedan springs, which translates to about an inch higher than it used to be with the trunk empty. In addition, I can no longer push the rear down so it's close to bottoming. The car is actually more stable now, with none of that swaying, floating, queasy feeling when changing lanes on the highway.
I'm sure the wagon struts also made a big difference, as my old sedan units were completely shot!
Are Merecdes TD springs heavier than the sedan's, or is the wagons SLS supposed to do all the load-compensating?
OTOH, maybe the stock W123 sedan rear springs are already stiff enough, unlike the too-soft sedan springs in a Camry (Certainly my 240D never bottoms-out like my Camry used to) Otherwise, heavier springs from a W123 taxi or emergency vehicle might still be avaible.

Happy Motoring, Mark

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DrDKW

The TD wagon springs are shorter and the SLS does the compensating.

His best bet for a spring swap would be a taller and thicker wire diameter compared to a stock w123, a w126 rear spring pn. 116 324 08 04. Or a step up stiffer w116 rear spring pn. 116 324 09 04. Or another step up stiffer w140 rear spring pn. 140 324 14 04


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1983 123.133 California
- GreaseCar Veg System

I'd like to avoid jacking up the rear with stiffer springs, if I can. The car already has crazy altitude, and such a stiff rear end that the empty trunk rings like a giant bell when it drops down off of speed bumps.

Interestingly enough, the Airlift 1000 product that I remember from about 20 years ago is still available. They're an inflatable bag that sits inside of the coil spring, and you air them up to fend of spring sag from loads. I never did hear anything bad about them, and they're pretty cheap. That said, they don't specifically offer a kit for a W123, which makes sense given the variety of springs and heights that were used. Still, a quick measurement of the coil inside diameter, and space between the top and bottom of the spring at normal ride height would be enough info to find the appropriate bags for each car. Getting the bags inside of the spring, however, would be a royal pain.

I'm still leaning heavily towards outfitting the car with factory style SLS, perhaps operated by an electric power steering pump. It seems like the easiest way to ensure correct ride height, no matter the load.

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- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work

My '77 300D progress thread

The Air Lift is a very good product. Very easy to install, I have it on one of my cars. But unfortunately, you got that shock passing through the spring on a w123.
Too bad they don't make one that goes out side of the spring.


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1983 123.133 California
- GreaseCar Veg System

Ah yes, that is right. It's the front with no shock in the middle. You must excuse me, I've been taking pain killers for shingles. Subsequently, my brain is a bit mushier than normal.

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- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work

My '77 300D progress thread

These guys make custom air assist....maybe they can help? They created a bag system for a w115...

Airassisted.com

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I had no troubles running empty on my 140 mile (round trip) commute, with long stretches of 65mph. Significantly more stable than my Ranger at the same speeds

__________________
$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment