My weird uneven spring height issue - guess the cause?

[grober]

I'm still fighting this issue.

I took delivery of some spring compressors on Thursday so Thursday night I took the springs and dampers out yet again and swapped them over, just to rule them out. I also replaced the upper shock rubber mounts (one was looking perished) and put in #1 spring pads both sides.

The job was sooo easy with the correct spring compressor

It didn't fix the problem though.



This is an interesting point... the camber has been checked by wheels in Motion and is reasonably ok. Ideally I'd like it perfect but it seemed a waste to spend money on it being done whilst I still had the height issue. Thinking about it though, I suppose the eccentric high and low could make a difference to the ride height, especially if either sides were adjusted on opposite spectrum's in order to get the right camber. In which case, I guess using spring pads to compensate may not be such a bad thing after all. (I think I need an expert to answer that with certainty). I'll climb under the car later to see if the eccentric adjustments differ much each side.

Regardless of the difference in ride height between front and left, these new MB springs make the car sit way too high. I've checked and double checked but they are the right ones for the car according to their markings but I cant live with the way the car sits. Has anyone tried just chopping off a coil of spring before to reduce the ride height? Seeing as I have two sets of springs, I thing I might try this on one set as an experiment.

I was also wondering if uneven rear spring rates could alter the ride height on opposite front wheels. If I compress the offside rear of the car I notice and increase in ride height on the nearside front. (maybe it is the rear springs I should have been looking at and not the fronts)

As you can tell, I'm clutching at straws really here.

Are the new springs coded blue [long]or red[short] I seem to recall there can be 2 length versions of the same springs but maybe memory playing tricks here. I would not alter the length of only one spring as suggested by GT as this would slightly change the spring rates side to side - better to achieve it by different thickness spring pads which play very little part in the suspension characteristics compared to springs.IMHO

 

[billy s]

Have you managed to find the cause of the ride height issue??

 

[Bellow]

Out on a limb...

Inbuilt compensation for the camber of the road surface so the car sits level travelling the road? For UK or uncorrected from European depending on what side is high/low.

Is the fuel tank central or offset? Some compensation for that? Possibly same height rear and offset loading of tank compensates the rear?

Left field I know, but it is a Mercedes. There will be a reason, even if it is an uncorrected one from the domestic market!

 

[Sp!ke]

From what I have read on Benzworld it is quite a common problem depending on combination of springs, shocks and camber setup etc.

In my case I have changed the following.

Changed shocks to Bilstein HD's - this will have the effect of raising the suspension by about an inch due to the higher gas pressure in these dampers.

Changed Springs for correct genuine mercedes springs - this will likely never provide a satisfactory look imho as the default setup on later post 1996 non ads cars was set to ride high after reports of complaints from owners fowling front skirts on high kerbs when parking. (allegedly)

Changed upper strut mounts - Mine were cracked and failing. This didnt seem to make any noticeable diffeerece other than peace of mind.

Now doing the above has not fixed the problem but having read up on this a great deal over the last few weeks, what I need to do is make sure the back springs are also a known good entity, not just the fronts. A worn or broken rear spring will cause an increase in ride height on the diametrically opposed corner. (the same as I am seeing).

So seeing as I am not happy with the OEM ride height, I intend to swap out the springs all round for some Eibach Pro-Kit springs. Only then will I have a starting point from which I can assess the situation properly.

Once done, I will need to juggle with spring pads to get the height perfect but the common consensus with my combination of Bilstein HD's and Eibach Pro-Kit springs is number 2 spring pads on the fronts and number 3's on the rears.

If I still suffer uneven ride height at this point (this can sometimes show up to a 1cm difference due to offset cams on the camber adjustment) then I may need to compensate a little by varying the spring pads between left and right.

Only then will I be able to get the alignment done properly. This may also have the effect of dropping the ride height again a little, especially on the rears, requiring fiddling with the spring pads once more to get it perfect (if you're **** about it like I am).

Assuming that they get delivered on time, I'll be fitting the Eibach Pro-Kit springs this weekend.

 

[Sp!ke]

I meant to ask.

Does anyone know if the Klahn spring compressors can be used on the rear springs on an SL or whether one has to unbolt the control arms?

 

[grober]

I meant to ask.

Does anyone know if the Klahn spring compressors can be used on the rear springs on an SL or whether one has to unbolt the control arms?

Don't know the answer but access may be limited compared to the front. Dropping the rear spring arm at the inner pivot bolt using a jack is so easy that that's the approach I would adopt. The rears are not so strong as the fronts which helps.

 

[Sp!ke]

Thats what I thought.

I know on the W124's that is the way it needs to be done and seeing as the R129 wa basd on the same platform, I suspected this to be the case.

 

[Animal Mother]

different profile tyre

Wot e sed.

 

[bolide]

A couple of thoughts. For the cause I was leaning towards different top mounts of different spring rates but you seem to have ruled both those out

One thing you could try is to remove the front springs, reassemble everything, remount the wheels and drop the car down on a couple of jacks till the car sits at the "right" ride height. Then measure the distance between the spring perches

This might prove difficult so fix a couple of steel rods in place between the mounts, cable-tied together. The rods will slide & record the lowest distance for the height you drop the car to

Also measure the ground to lower spring perch height and the ground to upper spring perch height on both sides with the car at the "right" height. This should tell you if there is any mechanical difference between the sides of the car

For the cause I was leaning towards different top mounts of different spring rates but you seem to have ruled both those out

Nick Froome
the independent Mercedes Estate specialists

 

[The mallard]

Has the car ever been in an accident................distorted body shell?

 

[Sp!ke]

According to the folks on Benzworld it is quite normal for MB's to need to be corrected with different spring pad sizes, some even come like this when new from the factory.

As a test I put weight over the nearside wing to see how much was needed to balance it out and 45kg was all it took to even it up. maybe it is just a natural imbalence of the engine, gearbox and ancilliaries.

Wheels in Motion confirmed that the chassis was straight so I'm pretty sure its not accident damage being the cause.

>Nick all measurements are equal as far as we can tell (there is no real fixed measuring point) as the design on both sides differ slightly.

 

[Sp!ke]

Looks like Saturday is on as hoped.

Koolvin - you coming over to assist?

 

[BlackC55]

Please use a spring compressor!

 

[Sp!ke]

I have the Klahn type so will do the fronts this way but was under the impression that the rears had to be done by lowering the control arm as the spring compressors dont fit - can you confirm Olly?

Also, if lowering the rear arm, do the upper strut mounts need to be undone? The US forums suggest they do but looking at Dieselmans post on the same job on a W124 he didnt need to.

This would likely save an hour's time of undoing everything to gain access if I dont need to undo the dampers.

 

[BlackC55]

The rears only need the lower arm to be undone at the "diff" end. No need for a tool.

 

[Sp!ke]

So I take it I can get enough movement in the lower arm without undoing the top of the damper?

If so

 

[grober]

So I take it I can get enough movement in the lower arm without undoing the top of the damper?

If so

Correct. the only slightly tricky bit is when you raise the arm again complete with new spring+pad- you will find the bolt is not exactly parallel to the front back axis of the car- this means the the arm needs to twist slightly to line up the mount holes in the subframe with the line of the bush insert at the arm end so the bolt goes thro. Careful placement of the jack under the arm can assist you there together with a little leverage and some one to push inwards on the rear wheel. You will understand this better when you do it- its not a major problem.

 

[Sp!ke]

All done.

I changed the front and rear springs for the eibach sportlines today and used a #1 spring pad on the front left and #2 on the front right and the car now looks much much better.

The springs have yet to settle but a quick tape measure already suggests it is now well within MB tolerances.

The car is now about 1 & 3/4 inches lower all round and looks infinitely better and importantly the ride doesn't seem to have been negatively affected thanks to the progressive spring design. The car no longer pulls to the left too which I am rather chuffed about.

So I'll let it settle for a week or so before deciding whether I need to play a bit more with spring pads and then I'll be getting the alignment done by wheels in motion to ensure it is all spot on.

The job of changing the springs was an absolute breeze. All 4 took me about 3 hours total (working at a snails pace) including all the other bits and bobs I was doing . If I was in a bit more of a rush I'd say about half an hour each corner with the rears being by far the easiest despite not using the compressor on the rears.

I'll post pictures of the ride height tomorrow.

Next job will be deciding on some new wheels - decisions decisions.

 

[E320Trip]

Would anybody know if the procedure for rear spring replacement is the same as this on an S210 estate? i.e. no spring compressors, nut on lower arm to be undone at the "diff" end, trolley jack de-compression and compression?

 

[grober]

Should be the same I think? Don't know if there are any snags associated with self levelling rear suspension struts if you have SL rear suspension, but the suspension arm hardware is pretty much identical AFAIK. çàï÷àñòè Mercedes: êîäû çàï÷àñòåé ìåðñåäåñ use new bolts/nuts washers to make a good job