1995 s600 sedan REAR SUSPENSON AND TIRES

[pvtconlimo]

HI TO ALL IN THIS FORUM. I WOULD LIKE TO KNOW IF ANY ONE HAS ANY SUSPENSION PROBLEMS WITH THEIR S 600 SEDAN. THE TROUBLE I AM HAVING IS THAT THE REAR SUSPENSION FEELS BOUNCY. IT IS LIKE IT BOUNCES, BUT NOT REALLY HARD. YOU CAN FEEL ALL THE BUMPS IN THE ROAD AND IT FEELS LIKE THE SUSPENSION IS ON THE GROUND BUT IT IS NOT. IT IS AT IT'S NORMAL HEIGHT. THE REAR SCHOCKS WERE REPLACED WHEN I BOUGHT THE CAR SO I CAN RULE THAT OUT. I HAVE HEARD THAT IT MAY BE THE ACTUATORS. LET ME KNOW IF ANYONE HAS HEARD OF THIS. ALSO I WOULD LIKE TO REPLACE THE TIRES AND I WANT TO GO WITH OEM.AND I AM LOOKING FOR ANYONE WHO HAS A GOOD BRAND THAT THEY LIKE. I WOULD LIKE TO USE AN H INSTEAD OF A V OR Z RATING. THANK YOU IN ADVANCE DOMINICK

[KenP]

Sounds a lot like a problem discussed on this forum many times related to cars with self leveling rear suspensions.
Run a search on "accumulators" and/or "spheres". Sounds like they need to be replaced.

[A. Rosich]

If your rear suspension is bouncy or "hard", definitely your hydroneumatic suspension is beggining to fail. Even though you mention that the rear shocks were changed, which is strange because unless they are leaking hydraulic fluid badly, they do not need replacement at all, ever (unlike spring or gas schocks which need to be changed in a regular basis).

What usually needs to be replaced are the accumulators and the overflow spheres as mentioned on the previous post. Usually after these are changed it will cure the "bounce" effect.

Although, this is true for the self-levelling systems on T-series and the sedans that have them (like the S 500). Not sure about is the fully hydroneumatic system in an S 600 will respond the same (if your car is equipped so).

If your rear shocks were actually leaking fluid, then your full system needed a full inspection (fluid pump, valves, etc) to see if there was an abnormal high fluid pressure causing the shocks to fail.

If you do not tend to drive over 120 m.p.h. constantly, then is safe and smart to switch to an H rated tire instead of V or Z. V and Z rated tires are much softer than H-rated ones and they tend to deform easier and definitely wear out faster.

Good brands to consider for your S 600 would be Pirelli and Continental.

One comment about tires on a S 600: a friend of mine has a S 600 L which has a very peculiar factory installed system. If a tire falls below 25% under the recommended pressure, the engine would not pass over 2,500 r.p.m. Until the under inflated tire is brought back to normal pressure, the engine would not rev fully.

I do not know if U.S. S 600 models have this feature, but as I understand, European and the rest of world market models do have it. Interestingly enough, it does NOT work with a pressure sensor on the tires (like the new W220s have, it works with a computerized revolution counter on each wheel).

[psfred]

Bouncy ride is bad accumulators. Replace them before they pound the struts to death.

About $100 each, plus installation.

I've been using Firestone Affinity LH30 tires -- nice ride, good handling, adequate grip on snow and ice, and not pricey. H rated, do not use if you or someone else will be driving at 100 mph or more!

Peter

[Gilly]

Sounds like they are on the right track as far as the suspension problem.

I'd only recommend Michelin tires on this car though. NO WAY I'd run a Conti or Pirrelli tire on this, no way. Michelin MXV4, you'll LOVE them and they'll last if you go easy on the throttle.
ONE thing to definitely remember on the 140 chassis cars, especially the V8's and V12's is that the MUST avoid using mounting fluid or paste when installing the tires. If they absolutely can't get them to mount up without it, then once the tire is spun onto the rim (before inflating the tire) they need to thoroughly wipe the mounting past off the rim and bead of the tire. The probelm is the combination of car weight and engine torque, if you really accelerate hard, will cause the tire to spin on the rim and ruin the tire balance.

Gilly

[psfred]

To say nothing of wrecking the bead on the tire!

Peter

[Gilly]

Not sure what you mean my this Peter.

I did say:

If they absolutely can't get them to mount up without it

I didn't say they absolutely CAN'T use it, but should be at least tried to mount without it, and if it seems apparent it isn't going to mount, then use it, but wipe it off before inflating the tire.
I've seen this happen quite a bit when a customer would buy tires at a tire shop. 2 miles after leaving the tire shop and the tires would vibrate really badly.

Gilly

[psfred]

Gilly:

What I meant was sliding the wheel around on the bead won't do the bead any good, either. No way dragging the seal surface along the rim circumference is good for it.

Peter

[Nikola600]

I have a 1995 S600 coupe, and have the same problem. The dealer and I have been chasing the bounce/vibration for some time. I think my next step will be the accumulators.

On the tire situation, I started with Michelin MXV4 plus tire but did not like the extra soft ride. They did not corner very well. I actually did not feel safe in them. I switched to a new Yokohama called the AVID V4S in a V speed rating with a 500 tread rating. I have had them for about 1000 miles and love the ride. They corner much better, no road noise, and track perfectly. Best part - 30% lower cost. Good Luck !!!!!

[DaveL]

Hi

Yes, there is no need to worry about the suspension - your accumulators are failing, replace them and it will be fixed (unless you have waited long enough to pound something else to death...)

I recently put new rims and tires on my 92 500sel (same car, except motor, as S600). I am running 235/50-18 fronts and 265/45-18 rears, Continental CH95. These tires are GREAT! I have had MXV4s, and Kumho ?, but these are quieter, stick better, and run down the road smoother than anything else I have run. (Granted, I was running 16", so it's not an exact comparison, but any way you look at it the CH95s are a great choice for this car - a performance touring tire as opposed to a performance track tire).

-David
92 500sel
86 560sel
85 535i
82 QPorte

[mrfixit]

I bought a set of Yokohama AVS DBS2 for my S320, I love(d) the quiet ride, aggressive directional tread and low profile (I returned the recommended 225/60/16 set for a set of 245/50/16 and received a full refund at Discount Tire/Yokohama within the first 30 days)

Great tire, unfortunately I forgot my number 1 rule with new tires, even though it never pulled...get it aligned!!

After only 7K miles, I have chewed up two of the S2's on the left side...and even after a laser alignment, they are really noisy, so I have ordered two more to replace and Discount was good enough to meet me halfway, even though it was my problem..

it was the left rear wheel that was out of alignment...