Soft Top wires/cables – how tight?

[jedwards]

Gentlemen,
I have an early RHD 250SL with the second generation soft top setup that should have the steel wire cables to help put tension into the “elbow” hinge above the window glass to pull it straight.  Both sides were missing when I bought the car.

As it looks a fairly easy fix so I thought I’d have a go, but I don’t know how much tension is required. The cable seems to be designed to pull the front of the soft-top down and to lock the elbow nice and horizontal  so it is parallel with the top of the window. My 107 used a  different mechanics but the same approach.  But  how much tension is enough?
Can anyone give me a guide?

If I retract the soft-top until I have about 1” or 25mm “bend” in the elbow, then pull the cable tight, is that going to be too little or too much tension? Any advice would be appreciated as I don’t want to inadvertently break something through ignorance.
Lastly, there is going to be pretty high forces involved, so what strength cable is required?  100kg, 250kg or 500kg?

[Larry & Norma]

If I remember correctly I did mine by pulling the wires taut whilst the roof was fully up.
There is no 'give' or stretch with these cables so if you make them too tight they will pull
out of the front fitting (Can be re-soldered )
Hope this helps

[jameshoward]

Not too tight. Did mine with mole grips, I think. Like Larry says, go too tight you'll break something. The cables are designed to help things along. The trick to a well fitting soft top is correct frame alignment (nightmare) and correct window adjustment (even more of a nightmare).

Buy new cables from any firm that supplies the tops. They should come as part of the kit, but are available separately.

[jedwards]

Thanks the feedback gentlemen,
From what you are both saying, the wires might not play the role I thought, which was to apply tension to the leading edge of the soft top in order to keep the top weather seal parallel with the top of the window.

I believe my car still has the original top so I suspect it is  mounted correctly on the frame, but I have a slight “V” in the elbow above the window, but only on the right hand side. Left is great.
From what you are saying,  it could the frame, not the wires, so is there a step-wise method of going about re-aligning the frame?
 I have tried easing off the 4 mounting bolts, jiggling the frame to make sure if is “free” to move, locking the front down and then retightening, but nothing seems to change.
Any thoughts?

[al_lieffring]

i install these cables with the top joint over the window just slightly folded, then install the cable tight as I can pull it with just my fingers. then when the top hinge snaps over center the cable has enough tension to  hold the seal against the frame but isn't fiddle string tight.

[jameshoward]

Thanks the feedback gentlemen,
From what you are both saying, the wires might not play the role I thought, which was to apply tension to the leading edge of the soft top in order to keep the top weather seal parallel with the top of the window.

I believe my car still has the original top so I suspect it is  mounted correctly on the frame, but I have a slight “V” in the elbow above the window, but only on the right hand side. Left is great.
From what you are saying,  it could the frame, not the wires, so is there a step-wise method of going about re-aligning the frame?
 I have tried easing off the 4 mounting bolts, jiggling the frame to make sure if is “free” to move, locking the front down and then retightening, but nothing seems to change.
Any thoughts?

It's the frame. You need to tinker with various adaptations of undoing and doing up the bolts. You can also use shims to change the angles slightly, catering the front or back of the frame to effect the elbow. My car has them (thin bits of metal, but think washers would do just as well). It's one of those amateur sports that involves time and luck. Someone experienced with the crummy frames would probably diagnose the alignment problem and fix it quickly. If you have someone near you who is a ninja, based on experience this is one of those rare occasions where I'd recommend throwing money at an expert to sort it. Your tinkering could well make things worse before they get better.  There are quite a few threads on the site (old ones) about the dreaded bent elbow problem. None of them will offer much insight I'm afraid.  Trial and error.

[mbzse]

I have a slight “V” in the elbow above the window, but only on the right hand side. Left is great.
From what you are saying,  it could the frame, not the wires, so is there a step-wise method of going about re-aligning the frame?

Like James H says, the "V" above the side window is a sure sign of a worn soft top frame... This sag cannot be easily adjusted (rectified).

A start is to look over the connecting hardware of the frame - tighten screws, and exchange them if needed.
One way to do away with the sag is to disassemble the frame, and bend (very little - perhaps a mm only) the "J" shaped frame part, then re-assemble and adjust as needed.
Advanced tinkering indeed.
I enclose a picture from Guenther in the German Pagodentreff Forum. Note: Black fabric inside is non-original. All our Pagoda cars had soft tops with tan fabric insides from factory (Sonnenland fabric)
/Hans in Sweden
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[jameshoward]

Hanson,
Thanks, that's useful.  I've managed to reduce the effects of the sag, but heaven knows how. Tinkering.

Are the screw you highlight still available? I imagine not.

James

[mbzse]

../... Are the screw you highlight still available? I imagine not.  James

Oh yes, at least SLS have them but I'm sure M-B Classic do, too.
Useful tip: The frame does need to be lubricated, in the joints of the frame as well as in the mechanism at the B pillar. Use some type of creeping fluid - and sparingly! You don't want the inner surface of the soft top (Sonnenland) fabric to be stained.
/Hans in Sweden
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