Hydraulic Compensator in 280SL???

[ctaylor738]

I just received a book entitled "Factory Original Mercedes SL" by James Taylor.  It covers the 113, 107, and 129 cars.  I was wandering through it last night and found the following statement on Page 50:

"On very late 280SL models, the compensator spring in the rear suspension was replaced by a hydro-pneumatic compensator."

This is news to me.  Has anyone else heard this, or seen one in a Pagoda?

Cheers,

CT

[66andBlue]

Chuck,
I have checked Engelen's book and there is nothing mentioned.
Perhaps the author had the R107 280SL in mind, as that possible?

[ctaylor738]

Anything is possible, but this statement is mid-way in the 113/280SL section.

[WRe]

Hi,
do you mean a Boge Hydromat which was standard in W111?
See here, it fits also in Pagoda rear axles: http://www.beetle.homepage.t-online.de/Hydromat%20in%20eine%20Mercedes%20Pagode%20W113%20einbauen.htm.
...WRe

[stickandrudderman]

The 107 has a completely different axle arrangement and so this definitely wouldn't have it.
I have never seen one fitted to a 113 but have substituted many for the spring in 111/108 etc. There is a Mercedes document for doing just that.

[sandcrab59]

Hi Chuck
Here is the final answer.
I have a 71 280SL manufactured in the last week of production .
Mine was 2/18/1971 Euro. I do not know if that makes a differance for USA models.
There was only 145 made after my car.
The answer is , there is NO Hydro unit. My car has the Coil spring.
Hope that answers your question.
Tom Mrowka

[ctaylor738]

Hmm.  I will see if I can contact the author and find out his source of information.  Personally I think it's bogus but you never know.

Cheers,

[mbzse]

.../...contact the author and find out his source of information.  Personally I think it's bogus.../..

Certainly no mention of it in the Mercedes "EPC", Electronic parts catalogue, which gives you the factory info online.

That said, any customer that insisted upon it could retrofit a Boge unit onto his/her W113 rear axle, just like WRe and Colin mentions (reply#3 and 4). So, occasionally you run into one.
/Hans in Sweden

[sandcrab59]

I forgot to mention in my last post.
I have a 1972 Parts catalog (Hard Copy) and it does not show a hydro unit. It only has a drawing of the coil spring.
Yes the EPC shows the same.
Tom Mrowka

[waltklatt]

Installed one in my 67 220SL and no problems.
Front end was so high due to lighter motor.
Rear was sagging with the spring, so a Boge went in to level it all out.
Works well.
Walter

[al_lieffring]

I Installed a H/P compensator on a 280sl that had a luggage box fabricated to mount in place of the trunk lid. The hydropneumat jacked the rear way up until he loaded it down with luggage.

[sandcrab59]

Chuck
I stand corrected.
I was looking in my Catalog A 1972 parts manual for an item and to my surprised in the rear of the manual Special versions. There was the H/P Compensator and the coil spring. So I guess you could have an H/P compensator as an option on the 71 models.
It looks like a fat shock absorber with a rubber boot on one end.
At one end it has a piece that screws into where the rubber boot is but it does not show where the other end of the piece screws into.
Tom Mrowka

[MikeL43]

I don't know about the 113s but my 1966 250 SE Coupe had a hydro pneumatic compensator spring (?) on it.  It went out when I was hauling a bunch of my household stuff from New Orleans to Tampa in the early 70s.  I replaced it with a spring which was suggested by my mechanic as the price for a new compensator was big bucks,  even then.
Mike L Safety Harbor, Fl
1967 250 SL just purchased, 2007 E 550
Previously had a 250 SE coupe-Great car, real quality and a 68 280 SL

[mnahon]

Hi Chuck,

In your search for information on this point, I thought you'd be interested in the following paragraph on page 90 of "Original Mercedes SL" by Laurence Meredith (Chapter entitled The 230SL, 250SL & 280SL):

"A further device to keep the swing axles in check under hard cornering is the compensator or equaliser spring first seen on the 300SL Roadster. This has a coil diameter of 11.9 mm (0.47 in) and is damped at its outer ends by narrow rubber bushes. This spring is fitted horizontally above and between the two halves of the swing axles just to the right of the differential casing. On late 280SLs the spring was changed for a hydropneumatic compensator which performs the same role in a more precise and refined manner. In appearance and effect, this device is similar to a conventional telescopic shock absorber but also provides a springing medium. As these hydropneumatic devices are expensive, many late 280SLs have been converted to the earlier coil type of compensator spring."

The mystery continues...

[66andBlue]

The mystery continues...

IMO, there is no mystery here.
Just another example where one author - Taylor - copies from an earlier author, Meredith, whose book has more errors than a Swiss cheese has holes.  

Hmm.  I will see if I can contact the author and find out his source of information.  Personally I think it's bogus but you never know.

Hi Chuck, did you receive a response?

[mnahon]

Just another example where one author - Taylor - copies from an earlier author, Meredith, whose book has more errors than a Swiss cheese has holes.

I tend to agree, but it would be nice to know how Meredith came up with such an elaborate misunderstanding. Seems unlikely he would have made it up out of thin air.

[garymand]

I've often encountered this.  First you can't always believe what you read, a. editors mess up paragraphs, b. authors have interviewed and get the idea wrong.
Second, Just because we think it, doesn't mean it is true. 

I was looking at California 280SLs in 1971 and never saw an SL with the compensator.  I only saw them on some sedans and many of those are gone do to the expense of replacement.  I think they added weight too, but there I go, thinking again.