Four-nub front spring pad?

are you building a rock crawler

DrewPT said:

On the parts diagram, it just has 14mm (2 nub) and 18mm (3 nub). Is the 4 nub no longer an option?
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Yes there is a 23mm 4 burrs front coil spring pad. The part number is 1263211084. Check it out:

I've always thought the front wheel wells were pretty large in comparison to the rears, and of course I have the characteristic rear left side sagging (which I hope will be gone soon). I believe the four-nub pads up front are original--if they give the appearance of a "rock crawler", why were they originally included?

The rear spring pads don't appear to have any nubs. I'll have to shove a ruler up there while the SLS shocks are out and attempt to measure their thickness, and determine if there was an original factory proportion from front to back.

DrewPT said:

On the parts diagram, it just has 14mm (2 nub) and 18mm (3 nub). Is the 4 nub no longer an option?
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Every W126 build had a specified spring (coil diameter and length) and spacer height (1 to 4 nubs) based on the calculated weight of the car and accessories included. If the ride height did not meet the factory specs when the car came off the assebly line, it was sent back to be reworked and the coil spring spacers were often changed to meet the ride height specs. As time and mileage build, springs change spring constant from metal fatigue and the ride height decreases. It is not important to replace the pads with the original thickness, but to measure the ride height and use springs and pads to bring the ride height back to original specs. Some people like to change the ride height for aesthetic reasons, but deviation form the correct ride height or tire size will affect (negatively) the superb ride these vehicles have. Before I get flamed, there are legitimate reasons (racing, mileage, clearance, etc.) that the ride height is sacrificed for ride quality.

I went ahead and ordered the 2-nub, 13mm pads, plus new springs (Genuine). My reasoning is this: since the car looks a little too low in the back (and I've read some accounts of after SLS and suspension bushings being replaced it can still be the case) and too prominent around the front wheel wells, and I'm going to have new springs installed anyway, those should make the car sit even higher after 36 years/300,000+ miles. A half-inch lower spring pad up front I can't imagine would make it look or feel worse.

Otherwise, with new springs wouldn't it sit higher anyway (particularly if I ordered new 23mm/4 nub pads)?

I have four nubs in front. when I bought them I actually did not understand the system and got original MB rubber. It seemed like a good idea with my new original MB coil springs. Now my front gap is approaching "rock crawler" territory and we will be cutting the coil soon (I have been trying to do this for some time, but "life is what happens when you are busy making other plans"--John Lennon). Then we will see what nubs seem appropriate for me.

Stewpot said:

I have four nubs in front. when I bought them I actually did not understand the system and got original MB rubber. It seemed like a good idea with my new original MB coil springs. Now my front gap is approaching "rock crawler" territory and we will be cutting the coil soon (I have been trying to do this for some time, but "life is what happens when you are busy making other plans"--John Lennon). Then we will see what nubs seem appropriate for me.

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It sounds by your experience, my reasoning is sound.

MBL87560SEC said:

My 560SEC [red daubed springs & the self leveling rams at the rear] has 4 nubs at the front .. Apparently.. I haven't made note of the rear spacers on that car..
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My Euro 500 without SLS has retained its original spring spacers from new.
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I couldn't find any nubs on my rear spring pads--unless it was indeed one that I mistook as molding flash. If both the SLS and non-SLS cars have one nub on the rear, but 4/2 respectively up front, I wonder if the rear SLS system led the engineers to decide the front needed an extra half-inch height?

DrewPT said:

It sounds by your experience, my reasoning is sound

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Yes, I think so. Many members have experience what I have, which is that ordering the correct spring has resulted in an increased gap in the front wheels requiring cutting. My best guess confirmed by several helpful members is that taking half a coil will bring it to near where I want it, and if I then have to, I can fine tune with a new lower nub spring pad.

Stewpot said:

Yes, I think so. Many members have experience what I have, which is that ordering the correct spring has resulted in an increased gap in the front wheels requiring cutting. My best guess confirmed by several helpful members is that taking half a coil will bring it to near where I want it, and if I then have to, I can fine tune with a new lower nub spring pad.

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I hope the new spring will eliminate the rickety creeking over speed bumps.

Any idea if the standard front shock bump stop (sometimes called three-nub but I'm going to refer to it as three-sectioned as to not confuse it with the spring pads) will still work without having to be cut? Each of the three sections are well over an inch/inch and-a-half in height apiece, and a 10mm shorter pad is less than a half inch. I'm sure my original bump stop is half gone anyway.

I've seen it recommended to cut off a section if the car is to be lowered. That may "technically" be the case here with the pad, but the new spring may even raise it to equal or higher.

Does it make sense that, since the ride height with the SLS system can be adjusted with the hydraulics, there would be no need for different thickness spring pads?

John350 said:

Does it make sense that, since the ride height with the SLS system can be adjusted with the hydraulics, there would be no need for different thickness spring pads?

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I thought the higher/more compensatory the SLS adjustment, the more pressure it puts on the system and earlier deterioration. I could be wrong.

John350 said:

Does it make sense that, since the ride height with the SLS system can be adjusted with the hydraulics, there would be no need for different thickness spring pads?

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@John350 This is a German car engineered by German engineers with a German mentality. Changing the rear ride height by adjusting the position of the SLS lever will get the ride height into the correct ball park, BUT the range that the SLS will compensate will also change and that would be out of spec. Maybe OK for most of us, but definitely a "no-no" for a German engineer with a German mentality. 😁 When the W126 was produced, the engineers were still in control of Daimler-Benz.

So, if it's not pads and not adjustment, what is it?

John350 said:

So, if it's not pads and not adjustment, what is it?

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Maybe they gave a range of pad options with these factors in mind--a "window" or range of adjustment. I guess the issue is why the SLS models by default came with 4-nub front and 1-nub rear, and the non-SLS a 2-nub front and 1-nub rear.

The fact they offer a 14mm thick 2-nub rear (only 4.5mm thicker than 1-nub at 9.5) I wonder, could be in anticipation of any SLS ride height oddities or suspension bushing issues, I suppose--or, since they would expect the owner would have the vehicles expertly maintained, maybe not. 4.5mm is almost unseen lengthwise on a car, so I really wonder.

DrewPT said:

I thought the higher/more compensatory the SLS adjustment, the more pressure it puts on the system and earlier deterioration. I could be wrong.

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You are absolutely right. A Mercedes mechanic advised me not to over-compensate the SLS adjustment as it could lead to premature wear.

I do not like my car's stance as it is raked forward. I like it level. The spring pads are 3-nub in the rear and 2-nub in front. I will have to replace the front to 3-nub to level the car.

The SLS rear springs are a completely different from non-SLS springs, so it would be a coincidence if they both called for the same pads.

Maybe I misunderstood; I though you were saying the SLS pads were not "numbered".

FatSal said:

You are absolutely right. A Mercedes mechanic advised me not to over-compensate the SLS adjustment as it could lead to premature wear.

I do not like my car's stance as it is raked forward. I like it level. The spring pads are 3-nub in the rear and 2-nub in front. I will have to replace the front to 3-nub to level the car.

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I didn't know there were rear 3-nub pads--unless you can use ones intended for the front on the rear.

So, if the SLS system is sagging, at least it's not over-stressed at that point in time (although it could be evidence of a past an SLS problem, aside from spring/pad wear, diff/subframe bushings)?

In my case, all parts are getting replaced, so maybe the thicker 14mm pad is a good insurance option for not only SLS stress protection-- but visually, particularly with new springs front and back?