for several years, and 27,000 miles, i have been driving a 2006 cl500[46k total]. i drive it with the abc "on" in the "c" setting all the time. and i drive fast.

i have found the drive to be supple, stable. and quiet when traversing harsh road irregularities.

and i expected the same with the 2006 cl55amg that i acquired two months ago. but i am now wondering if the abc suspension has been set up differently for this vehicle. again, with the abc engaged in the c setting, i find the rear suspension is very noisy over even minor road irregularities. and it feels like, sounds as if the right rear is rebounding multiple times, noisily, over even minor road surface irregularities.

initially, i thought that the issue was one of cold fluids, since i first noticed the issue during our recent below freezing weather. and the noise and the harshness tended to subside after about ten miles of driving.

i mentioned this to my dealer dervice gurus last week when the car was in to correct what the selling dealer, sfbenz, overlooked in their cpo exam. my gurus, whom i have known for 3 decades reported that everything checked out.

and indeed it did seem to run like my cl500 over the last few days.

but....today i took it out, it ran just like my cl500. then i parked it on level ground, on asphalt, during a warm afternoon[80F] for about 20 minutes while i did some business at the county courthouse. returning to the car, driving away, i found the rear suspension to be once again unnaturally loud when thumping over minor road irregularities. it sounded as if the right rear was double-thumping. over 20 miles, this noise and this harshness seemed to dissipate.

is there a suspension issue here that the dealer's service tech missed? or does the cl55amg have a suspension that is noisier, harsher than the cl500?

all ears.

Yes, any AMG car with ABC rides lower & stiffer than normal ABC cars.
Of course tire profile on those cars make a difference as well.

There are several items that really need attention on ABC cars so you don't have
to SPEND $$$$ on repairs.

The original filter in the reservoir should be replaced EVERY 30K & the fluid as well.
Also the accumulator (damper) needs replacement every 30-50K miles as well.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

thank you. it was my conclusion that some maintenance by previous owner/lessor may not have been done.

by the way, would there be any diagnostics to discern this situation? or is it just the need to replace certain components after so many miles?

MB doesn't suggest any preventive maintenance on ABC systems.

What I am suggesting is relative to conditions & repairs that cost $$$$+
The best thing for that system is a new filter & clean fluid.

Pumps are $2k installed & each strut is $1500+.
Both are common failures when the systems fluid gets "dirty".

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Don't forget the pressure supply valves. The car has three different ones, and they're $900 each.