r129 sl500 AMG suspension spring identification

[wub]

I am renovating the suspensions, brakes , ADS etc of a 1998 sl500 with ADS. One of the rear springs was broken , so I bought a used pair for the same year sl500. I just went to fit them and noticed they are about 25mm longer than the originals with different colour bands painted on them.

I did a bit of googling and found a post that suggested, if these cars were fitted with the AMG split rims, the AERO II, 10 inch rears (SL73) wheels at order, which mine has, then the wheel option included some undercarriage alteration (whats this?), rolling of the rear arches, to carry these 10 inch wide rear rims and 25mm lowered height.

That would explain the shorter rear springs i have (part number 1293241204). But I checked the front springs with standard SL500 1998 springs i had, and they are the same length as mine? So it seems odd to me that Merc, at order stage, would have lowered the rear springs and not the fronts? So maybe my front springs have been changed at some point and the wrong ones fitted. Of course you would not notice as the self-levelling ADS system would have compensated for the mistake i would have thought.

I cant read the part numbers off the front springs i have unfortunately.

Can anyone confirm, ordering these rims as an option from new, came with these other mods, inc 25mm shorter springs? And if so, anybody have the part number for the correct front springs?

 

[Richard Moakes]

Let me know your VIN and I will see what springs EPC says should be fitted to your car

 

[wub]

Great thanks WDB1290682F175991

 

[Richard Moakes]

Right, it took a while to lookup your datacard, add up the points etc., but here is what I think was fitted to your vehicle

Interestingly, datacard for your chassis shows SA codes

793 - AMG 8 5x18 245/40 SEV Parts
774 - Shell modification for AMG wheels

WDB1290682F175991

Blue are normal springs, red are softer springs

Front - 43 + 4 +3 + 1 = 51 points

A1293211804 Front Spring
A2013211184 (Pad Blue Spring)
A2013211284 (Pad Red Spring)

Rear = 38 + 3 + 1 + 1 + 1 = 44 points

A1293241204 Rear Spring
A2013251044 (Pad Blue Spring)
A2013251144 (Pad Red Spring)

 

[Richard Moakes]

Found this

 

[wub]

Thanks Richard. so what are SA codes? And what are the points?

 

[Richard Moakes]

SA codes indicate equipment fitted to your car, the points are calculated from the options

Each option has a number of points, auto trans is 3, stereo is 1 etc.

 

[wub]

i managed to read the part number off the front springs i just removed and they are different to the part numbers you listed above, mine are 129 321 1404. So i suspect the front springs have been replaced at some point in the past with the wrong ones, hence why they are not 25mm shorter than standard ones, like the rears.

 

[Richard Moakes]

I will check that part number later, see if it was applicable to ADS equipped cars

 

[wub]

so do the retaining rubbers / shims vary in thickness and softness? i assumed they were all the same.

 

[toby1]

Yes they differ. The thickness is doubled at the wheel, so for example a 5mm shim will make 10mm difference in ride height.

I don't know about 129s but on 140s one can feel the shim thickness by the number of 'knobs' at the top of the shim in situ. I had a nightmare trying to sort this out on my CL, not helped by MB changing the heights and some springs NLS.

 

[Richard Moakes]

A1293211404 is superseded by A1293211804, so the correct springs were fitted.

As Toby says, shims are another issue, and greatly affect ride height.

 

[toby1]

Richard, do you have WIS or some other MB system? From where do you source your excellent information?

 

[Richard Moakes]

Richard, do you have WIS or some other MB system? From where do you source your excellent information?

That’s exactly what I have, EPC, WIS, ASRA in a virtual machine

 

[wub]

wow, much more complex then i imagined! I still dont understand why the rear springs are shorter than standard by 25mm and the front ones are not? I guess its where they sit under the load that counts. So just to confirm, for my chassis number, the correct springs are fitted all round? if so, Merc know best, so i will stick with that and just find replacements, like for like.

 

[Richard Moakes]

In an ADS equipped car, the springs don’t seem to be able to hold the vehicle up without hydraulic assistance. When I had a rear hydraulic line failure, the car sat down on the bump stops and it made me wonder what was the purpose of the springs. I suspect that under normal operating conditions, they work in conjunction with the hydraulics in a complex manner that I do not understand.

 

[wub]

So were all r129's fitted with ADS have self leveling, or was that another option to be added if required? I have another 98 sl500 where previous owners have removed the broken ADS system and replaced with normal springs and shocks. all seems ok, but i cant get high beam on the head lights and someone has suggested it might be cause the self levering system is not working and it needs to be for the headlamps to adjust?

 

[Richard Moakes]

ADS is self levelling by definition, so it’s not a separate option.

On ADS equipped cars, the headlamps are levelled by the suspension, on non-ads equipped cars, there is usually a vacuum powered headlamp level adjustment mechanism, with rotary switch next to the headlamp switch.

Does your other car have HID lights? If so, it’s mandatory for either the chassis to self level or for the headlamp itself to self level so as to ensure no dazzling of oncoming road users.

 

[wub]

Yes the other car does have HID, but i think previous MOT people have tried to get it to preform correctly, and failed, as there is very poor dipped beam and dangerously zero main beam! It wont work as the ADS suspension has been removed, but the front and rear sencors and bracketry to the torsion bars is still in place, but the rear bracket has rusted through and snapped. I'm guessing if this is replaced, then the sensors will know where the car is and the headlights might work? It looks like the ADS dampers etc were removed a good few years ago and i cant believe its not been driven in the dark since, as its impossible now with the lights they way they are, so someone must have got the lights working.

 

[Richard Moakes]

if the car had factory HID’s and self levelling suspension, there may be no levelling mechanism in the headlights?

I think I would be looking to retrofit conventional headlights, and set them up manually