W140 Non-SLS Rear Suspension Sag (98' S420)

[yojay]

As titled I have a 98' S420 W140 without SLS, and the rear suspension runs too low.

As you might be able to see from the (random, crappy) pictures, the rear has about 1" of clearance between the arch and top of the tyre wall. A couple of MB specialists, PCS, WGMB and Starwerx, have seen the car and agree the rear runs too low.

The car runs an LPG kit with a small, 40l toroidal spare wheel well tank. I suspect this extra weight is contributing to the issue. With rear passengers the car will frequently bottom out over bumps and undulations.

So far I have changed the rear dampers and springs to Bilstein OEM spec which hasn't helped the ride hight. I refreshed the rear tired stock suspension using the following parts:

BLS24-017077 (Bilstein B4 Gas Shock Rear Absorber)
BLS36-129577 (Bilstein B3 Original Equipment Rear Spring)
Also added in the thickest shim (4 notches IIRC).

I've changed the front too (which remains at a normal height), and the comfort and handling have both really improved. However the rear ride hight is exactly the same! :fail

I'm hoping to rectify the sag with some firmer / taller springs. Looking at the MBOC EPC, there are two spring options, the firmer option for cars with lots of OE equipment (rear elec seats, fridge etc) is A1403242104 AFAIK. I don't want to buy the OEM springs from MB because of the cost and the fact that they might not resolve the issue. I also don't have the original springs for part number reference.

What I have seen is both, Lesjofors and Kilen sell a "reinforced" spring for the W140. It doesn't give any further info, just says, "for vehicles without leveling control - Reinforced Version". I'd go for these straight away, they're cheap, but their OEM equivalent number doesn't match anything I've seen in the EPC for my car.

The OEM equivalent number for the Lesjofors reinforced spring is A1403241404. I'm not an EPC pro and haven't managed to reference this number against my car, so I don't know if they will fit / fix the problem?

Long shot - but can anyone shed some light on the Lesjofors spring compatibility or recommend a solution?

Cheers!

 

[grober]

The LESJOFORS SPRING number you gave appears to be for heavy duty rear springs pre 95 which seems to be a break point before /after for springs for these cars. Would not perhaps be applicable your car being a 98? Really depends on if the change affected fit or spring rate [ the w140 supposedly lost weight after its facelift] I have checked several well known aftermarket suppliers but non seem to list an equivalent to the MB A1403242104 the heaviest duty rear spring for post 95 cars. The other thing to watch was this was a period when Mercedes often featured 2 springs with the same rating and part no but different heights [ to be accommodated on fitting with different pad thicknesses] they were colour coded red[short] and blue [long] I'm not sure if this still applies after many years. Have you enquired about the price of the MB A1403242104?

 

[yojay]

Thanks for looking into this and checking suppliers, Graeme, it's much appreciated. The price of A1403242104 is c. £100 ea. Which is a bit much for me to test the theory.

You mention the the spring pads; On the EPC there are 4 spring pads for the car, however each has a red and blue option. Does the red and blue mean it is suited to a red or blue dotted spring, or does red and blue affect the spring pad thickness itself?

The spring pads are numbered 1 - 4 which I assume related to the number of notches (thickness). In your experience, would A1403250484 Red, have a different thickness to A1403250484 Blue?

I've probably got this wrong and red and blue relate to the springs, the softer springs are blue, for example, and the harder springs are red.

 

[grober]

AFAIK the colour codes refer to the springs red[short] and blue [long] only--- Normally the springs have 4 colour stripes/dots one of which is the long / short thing. I think the 4 spring pads are the same for all springs [short and long] the number of pips/burls 1 to 4 correspond to pad thickness 8,13,18,23 mm- remember that because the springs are inboard on the suspension arms this translates to an "amplified" change in ride height.
best explained with an example:-

using the HD rear spring A140 324 21 04
the long spring [blue] uses pad A140 325 03 84 18mm 3burls
the short spring [red] uses pad A140 325 04 84 23mm 4 burls

thus preserving the same ride height for two different lengths of springs.

I have never understood the MB long/short spring thing but I am guessing that present day aftermarket springs are a middle height "one size fits all " only-- relying on the spring pads to adjust up and down. Its possible the original fit spring was blue [ long] such that even with the thickest pad plus a mid height aftermarket HD SPRING the ride height is reduced with the extra weight of that tank???
Aftermarket manufacturers such as Hand R or Eibach may offer even higher spring rates but are normally "lowering" type springs by about 30mm ride height
hope this makes some sort of sense.

 

[grober]

Another long shot-- would a set of air assist bags [ they fit inside the spring] possibly help?
e.g. https://www.airliftcompany.com/products/air-springs/air-lift-1000/

They don't list a kit for your car but if you supplied them with the rear spring dimensions they might be able to come up with something?
https://www.airliftcompany.com/products/air-springs/air-lift-1000/

 

[yojay]

best explained with an example:-

using the HD rear spring A140 324 21 04
the long spring [blue] uses pad A140 325 03 84 18mm 3burls
the short spring [red] uses pad A140 325 04 84 23mm 4 burls

thus preserving the same ride height for two different lengths of springs

Graeme, thanks again for your help. Does this mean one spring P/N could have two lengths depending on it being marked blue or red?

Aftermarket manufacturers such as Hand R or Eibach may offer even higher spring rates but are normally "lowering" type springs by about 30mm ride height hope this makes some sort of sense.

I did see some NOS Lorinser lowering springs for sale a while ago, but as this is my wafter, I want to keep the ride height as tall as possible ! It's perfect for speed bumps and mile munching.

 

[yojay]

Another long shot-- would a set of air assist bags [ they fit inside the spring] possibly help?
e.g. https://www.airliftcompany.com/products/air-springs/air-lift-1000/

Ha ha, great idea!

If I can't find a spring solution, I could fit a pair of spring assisters which would do something similar to the airbags I imagine. I've not used them personally, but they're meant for towing etc.

https://www.amazon.co.uk/26-38mm-Spring-Assister-Supports-Suspension/dp/B00GY8JXRS/ref=sr_1_1?s=automotive&ie=UTF8&qid=1492547650&sr=1-1&keywords=spring+aid

 

[grober]

Graeme, thanks again for your help. Does this mean one spring P/N could have two lengths depending on it being marked blue or red?

Crazy as it seems the answer might be yes but the whole MB spring thing is a minefield.

 

[yojay]

Crazy as it seems the answer might be yes but the whole MB spring thing is a minefield.

 

[219]

I’m kind of in the same place with my W140 , and having fitted a towbar , I need to look at different springs . I see a set of ones with blue markings going cheap on eBay , and might try these with a set of the thickest pads ; also there is a set from a 600 , which on the one hand would be a fully loaded car , but on the other would have SLS as standard...

my other thought is that my Indian Built W124 had an extra high suspension for the rough roads out there and it still looked great to me ; I wonder if there were different springs for the W140 in the Indian market ?

last option would be to retrofit SLS , but I’d really want to strip it all off a donor car to see correct fitment of all the components ( and get the hydraulic struts ) . I’d guess the 6cyl cars ran a tandem pump like the estate cars . The plumbing wouldn’t bother me as I make my own brake pipes anyway , just need to figure where the spheres would go ( and look at new rather than used as they are usually the second most common fail point , after corroded pipes ) .

however , this is NOT a job I’d start while my 140 is my only car ; a spring swap I can do in an hour or so since I have the proper compressors , shocks easy to do at the same time so happy enough to do that during a Saturday or Sunday downtime , but SLS installation , at best , would take me a few days working on the drive with ramps and axle stands .

oh , and yes my W126 500SEL was exactly the same , helped a little by new genuine springs , thickest pads and I can’t remember which shocks , but would’ve been either Bilstein or Sachs/Boge , since I don’t fit unheard of makes .

 

[219]

I just ordered the Lesjofors springs as detailed above , along with a pair of Febi Bilstein 23mm spacers ; hopefully that will lift my car back up since it now sits with the tops of the rear arches about an inch below the tops of the tyres - the current springs are not broken ( I checked ) but with a full tank of fuel and , more recently a towbar fitted , the car sits far too low . I think my rear springs are probably original to the car as they are very rusty , but the previous owner had fitted new front ones about a year before I bought the car . I'm not using the towbar for anything heavy , just a carrier for two bikes and occasionally my small Erde trailer which does not have excessive nose weight .

There was a thread on Benzworld where someone with the same problem fitted these springs ( supposedly equivalent to the MB HD ones ) and the thick spacers with the desired result .

My shocks seem fine , so I won't change them for now .

 

[219]

Well the lesjofers springs arrived today ; they look spot on , and it even says on the box they are the HD ones and fit my car - so no worries there .

Alas the Febi-Bilstein pads also arrived , and despite having a 140 part no , they are tiny and fall down the middle of my springs , even though they do have four bumps and look a good thickness - they were less than a tenner each so not worth the bother of sending back ; I just need to do a bit more research and order the right ones next time . The ones I received today are 140 325 04 84 , and while the correct thickness are much smaller in diameter :-(





I may jack the car up and remove one wheel to see what pads are in there ; if already max thickness and still in good order ( I suspect they won't be ) I could just fit the new springs with them since it's only a 15 min job with the Klann spring compressors I bought to do the job on my W126 .

 

[grober]

Those pads will possibly be for the smaller diameter "assist springs" for cars with std self levelling rear supension [ non ADS]

Mercedes Benz EPC 140.033 Chassis Information Everything Benz

 

[219]

Thanks for that , my car is actually a 140.032 , but it was easy enough to navigate to the appropriate page . There seems to be a choice of two four burl pads , one of them is the part no I already have , so I'll try ordering the other one .

 

[219]

Interestingly , looking at shock absorbers on the same sheet , there are numerous annotations , including mention of Option 482 : springs for higher ground clearance .

Looking again at the numerous springs they are all 'as required' which will depend on the spec of the vehicle , but most mention 'not for option sports underwear with 4 AMG Li Rims' ; only two of the springs are prefixed HW ( heavy weight ? ) , alas none mention option 482 , so it does not say which are the ones for higher ground clearance .

More research I think ...

 

[219]

The rear shims which turned up and were too small were A140 325 0484 ; the EPC also listed A140 321 0984 as applicable to the rear axle on the 140.032 and I found these listed as a pair for £20 with postage included so have ordered these . Curiously the vendor lists them as front spring shims , but the EPC definitely lists those as applicable to the rear axle so I have ordered them since we aren't looking at a fortune here .

The Lesjofers springs I bought , although it says on the box only for cars up to 1995 , are marked as parts no A140 324 1404 , and again this is listed on EPC as compatible with my 1999 car , and also on the vendor's website .

The new shims should be here at the weekend , so I'll be looking at doing the job then .

Also need to look at my exhaust as it has started leaking somewhere around the middle ; will look to patch it for now as I'm not quite flush enough to buy a full stainless system yet , but will look at doing that in the not so distant future .... another visit to PD Gough methinks .

 

[grober]

My guess the springs PADS you got were 112mm diameter and what you need are 130mm diameter- unfortunately could only locate 8mm thick ones 1 pip- you might have to fabricate some spacer rings if the new ones ON ORDER are too thin.

 

[219]

My guess the springs PADS you got were 112mm diameter and what you need are 130mm diameter- unfortunately could only locate 8mm thick ones 1 pip- you might have to fabricate some spacer rings if the new ones ON ORDER are too thin.

Yes , I just measured them and the pads I received are indeed 112mm in diameter , and my springs 130mm diameter .

I know the terminology varies , both the EPC and the vendors describe them as shims , but we are talking about the same things anyway

Hopefully the new ones , expected on Friday , will be 130mm diameter and I will fit them over the weekend , weather and time permitting . I also have brake pads to change on my sister's Golf and , on my daughter's Polo , starter motor to remove , dismantle , clean , lubricate pinion gear , reassemble and refit to stop an annoying screech that has started recently when she starts the car !

It never ends .

 

[ivan1983]

Not sure if you have already started work but as you have noticed the diameter of the springs changed on the w140 between face-lift.

I had ordered the wrong ones and the spring perch is different.

I have some old springs from a well optioned s500 with sls if you are interested. They will be going to the tip at some point unless they find anew home. Rusty but not cracked, I replaced them as I was doing a refresh of sls spheres etc

 

[219]

Not sure if you have already started work but as you have noticed the diameter of the springs changed on the w140 between face-lift.

I had ordered the wrong ones and the spring perch is different.

I have some old springs from a well optioned s500 with sls if you are interested. They will be going to the tip at some point unless they find anew home. Rusty but not cracked, I replaced them as I was doing a refresh of sls spheres etc

I haven’t started yet , but , if the EPC is to be believed the 130mm diameter springs I have should fit my 1999 car .

The pads I received certainly are a much smaller diameter than the springs . Assuming the new pads match I will remove a wheel at the weekend and check compatibility.

If the springs are wrong , I will return them as the vendor’s website clearly states they fit my model/year of car . They also quote the part number of a spring which EPC states will fit my car .

According to EPC , you need different springs for SLS and non SLS cars . The SLS springs are weaker and probably won’t suit my non SLS car .

If the diameters are different I’ll just put the wheel back on and take up with the spring vendors .