My weird uneven spring height issue - guess the cause?

[Sp!ke]

Today I had the day off so set about changing the front springs and shocks on my SL500.

Suffice to say that it was a fair amount of work as I didn't have the special Mercedes spring compressors.

Anyway, the long and short of it is that having changed the springs and the somewhat tired shock, plus the ARB bushes, yet the same 2cm difference in height is still prevalent between each side of the front of the car.

This confused the hell out of us so much probing later and we think we've figured out what is going on and we've ordered a part for delivery tomorrow. At this point were 80% sure we've nailed it but until the part arrives and we inspect it we cant be 100% sure.

I wonder if anyone can guess what part it is and where we believe the problem lies. (It is a strange one).

Anyone hazzard a guess?

 

[Niks]

I had this same problem on my W124, one side was 15mm lower than the other side at the front. I managed to track it down to the coil shims, the rubber pad had completely worn out from the inside. I changed the front 2 coil shimms with new ones and the car was even both sides dead on. So try that, if that helps.

 

[nigel cross]

Broken rear spring?

 

[Sp!ke]

Not the pads and not the rear spring.

 

[Niks]

Ahh, self levelling suspension thing, or automatic ride height adjustment?

 

[Sp!ke]

Nope, no SLS system on the car, just a normal setup.

 

[Dee-124CAB]

My passenger side rear is abot 1cm lower than the other side on my W124 Cabriolet...& I have had the springs changed to H&R items, the shocks to Bilsteins & all the shims changed to the thinnest ones...... So I would be interested to hear about your findings Spike, because as it stands im miffed....

 

[Will]

Does the R129 have the rubber top mounts for the shocks like the 124/201s etc?

Ermm, other than that I'm struggling to think at the moment - can we get a hint as to whether it's a part that is being replaced for 'wear and tear' or as a result of damage?

Will

 

[kth286]

do you have the thin spacer under each spring to prevent rusting of the spring - they are only fitted to British and Scandinavian cars.

Perhaps one side was missing.

 

[Will]

do you have the thin spacer under each spring to prevent rusting of the spring - they are only fitted to British and Scandinavian cars.

Perhaps one side was missing.

'sacrificial anode' I've heard them called

 

[stevesey]

Not the pads and not the rear spring.

But something at the rear? Shock?

Or has someone tightened bolts up with the suspension hanging so a bush is under tension when it's back on the ground?

 

[grober]

Mismatched lower front suspension arms with different angle ball joint holders?

 

[wemorgan]

mixture of worn and new tyres plus some tyre pressure variation?

 

[jaymanek]

roll bar links?

 

[LTD]

different profile tyre

 

[Will]

Sp!ke's teasing us - no updates for over 1/2 hour

Will

 

[Niks]

parked on uneven ground?!?

 

[Sp!ke]

I think Grober is close enough. :bannana:

The left and right hand side wishbones are subtly different.

On one side, the end of the coil spring seats in a hollow towards the outside of the wishbone and yet on the other side of the car the shape of the hollow in the wishbone dictates that the last coil of the spring must end towards the inner side of the spring seat. There is a distinct height difference in the way that the springs sit in the wishbones, not to mention different leverages involved.

Looking at some other Mercs, on all of them we checked the last coil of the spring end the same on each side side of the car (except on my SL). The two W140's I checked the coil finishes on the outside of the wishbone and on my W124, they both end on the inside of the wishbone.

So my suspicion is that my offside wishbone is actually for a W124 and not a R129. I'm still bemused how and when this would have happened as both wishbones are genuine MB items and both would appear to be around the same age. Given that wishbones aren't exactly a consumable item, they've either been fitted incorrectly from the factory and no-one noticed the height difference for 11 years or for some reason one or both were replaced at some point in the vehicles lifetime...quite some time ago judging by the way they look. (why would you need to change a wishbone anyway?)

Whichever way you look at it, the problem had gone unnoticed for a long time and it wasn't until a Mercedes geek like me took ownership of the car did anyone notice the height anomaly.

We'll know for sure if we're right tomorrow when we get to look at two correct R129 wishbones.

 

[jaymanek]

Wishbones are a common item to change... mainly because changing the ball joint alone is a pain and its often easier to change the complete wishbone.

 

[Will]

I think on some MBs the lower ball joint fitted to the wishbone isn't replaceable seperately either, eg six-cylinder W124s?

Will