w124 wagon...rear sag
 

ok... so i'll be replacing the SLS accumulators before the year ends... question is: do i replace the rear springs also?...

right now the accumulators are shot... i have a super bouncy rear... with a pathetic sag.

does this mean i need new springs? i'm under the impression that if the SLS isn't working... i should at least have the correct ride height with zero load, correct?

i just did mine -after the accumulators were replaced, everything on the rear went back to normal - ride height and all.

On my '91 when it was new, I was told that the springs would support the un-loaded car at proper ride height and the SLS system was designed to support additional loads, not bear weight all of the time. Could be incorrect, but it makes sense to me.

I can't remember exactly how long the job took me, but much less than five hours, probably more like two or three. The only tricky parts were finding all the screws to allow the floor panel between the 2nd and 3rd row seats to be removed and slightly awkward access to the hydraulic connections at the accumulators which were very tight to undo.

thanks for the replies guys...:)

hmmmmm... so i don't need new springs?

it's a DIY job? i may have access to a lift but i'm not so sure... i looked under the car and saw at least 3 nuts holding the accumulators... i've read that the connectors may pose a problem... any tips? i'll do a search shortly. :)

... after removing the nuts holding the accumulators... do i do the next steps up top?

heehee... found the info i needed. :)
http://www.peachparts.com/shopforum/showthread.php?t=86379&highlight=124+sls+install

If it is low, you might consider new spring pads, the more bumps the thicker the pad and the higher the neutral point of the unloaded suspension.

so i had my ACCUMULATORS replaced... now the ride feels a whole lot better, and the car doesn't SAG anymore... i still have to adjust the ride height a bit higher since when viewed from the rear... the tires still slant a wee bit inwards.

on to my problem...

i'm still under the impression that even with the SLS faulty/disconnected/removed... the springs should support the car at the proper ride height, even without hydraulic support. (i read it somewhere in the forum)... (i also remember someone mentioning, also in the forum, that the springs need a little bit of hydraulic help...hence my confusion)

any inputs?

if i do indeed have to install new spring pads... doesn't this also indicate that my springs are going bad?

I thought they were there in place of shocks. I believe they are also to redistribute support when cornering and things like that. They do dampen the ride a lot. The SLS on my wagon was replaced with shocks and it rides pretty hard now. My SEC has its SLS intact and is much smoother.

I haven't read in the factory repair manual that the springs solely support the unladen car. And given the number of cases in which the springs do not, including my wagon with 70,000 miles, I think the SLS normally provides some lift to an unladen car.

Sls
 

Spring pads are rubber and springs are steel, so one "going bad" does not correlate to the other one "going bad" in any known way.

The springs do support the body weight, but not exactly at ride height. The rear struts contain fluid under pressure, which brings and keeps the rear at the factory correct ride height.

Did you flush the system thoroughly with at least two liters of the proper fluid?

The ride height can be changed slightly by adjusting the connecting rod on the SLS valve.

yup. the system was flushed properly. :)

it's actually ok right now...

just want to double check that i'm not straining the sls system by not changing my presumably weak springs.

i know that the pads are just spacers... i just thought that solving the ride height by changing to non-spec/stock pads was just band-aiding a weak spring problem. :)

i'm good now... just double checking.

Sooooo... will a perfectly good set of springs SAG with a non-working/as in dry SLS system?

I believe an unladen car will sag without a functioning SLS. Save your money for something else.

Spring pads are cheap, SLS parts are expensive.

The fluid is designed to be under some pressure to raise the boiling point of the fluid just like regular gas-shocks, thus it is logical that there would be some weight borne by the SLS system. However, the rubber pads will lose resilience as well as shape over time, even if the car only has 70,000miles, it is logical that the ride height will drop over time. The more pressure on the SLS system the more stress and the earlier the failure.

Another example is the non-SLS sedans. Both of my '87 300D sedans drooped in the rear, needed new spring pads or springs. Typical of other bodies as well. One can easily deduce that the same would be true of the wagon with a heavier rear on the same material pads, and thus a new set would be prudent.

It's my understanding [from reading many posts], when measuring from the center of star on axle to fender lip with engine off the rear will be about 1" lower than the front. When engine is started, rear will rise to very close to height of front. And the variance from side to side should be no more than 1/2 in.

There's a thread discussing the ride height with a variety of reported measurements. I have yet to see the "factory spec" ride height.