Removing the Sports Package Suspension for the Comfort.
First, I'll define my terms. Comfort or standard referes to the non-sports package suspension. Sport refers to the sport suspension.
My 2010 SLK350 Sports Package road like a dump truck. It crashed over minor irregularities in the road. Any pot hole it might encounter was a dramatic fearful event to be avoided at any cost.
Before going into any details, observe the following numbers. They measure the ride heights before and after changing the front spring from sport to standard. The ride height is measured through the center of the wheel from the garage floor to rim of fender.
Driver 26 1/8" (26 1/8") 25 5/8" (26 1/8")
PAX 26 1/8" (26 1/8") 25 3/8" (25 7/8")
The numbers in parentheses were taken after a couple of hundred miles of driving. Notice the front ride height increased exactly 0.5" the goal of this modification.
Before I go on, I want to verify the part numbers for the Sport Suspension. Remember, I removed or examined them.
Front Spring - 171.321.10.04, 1 Yellow 2 Blue
Rear Spring - 208.324.00.04, 2 Red
Front Strut - 171.320.34.13
Rear Shock - 171.326.10.00
The part number, from a label pasted to the strut, doesn't agree with the Mercedes part diagram, 171.320.12.30:
For the comfort suspension, I put a complete new front strut assembly in composed of:
Bilstein Strut - 35.113430
Suplex spring 19355, Mercedes part number 171.321.09.04, 1 White 2 Blue.
New strut mounts
I didn't take apart the old strut, so I didn't have the rubber spring seat. I assembled it without it, and I haven't experienced any problems.
I replaced the rear shock, 171.326.10.00, with the Bilstein shock, 24.113441.
How does the car ride? Well it isn't all that great! The front does ride a bit better, and the extra ground clearance is appreciated. However, the rear rides very rough and skates over rough pavement and makes a lot of noise.
I'm considering changing the rear suspension. The only thing left to do is replace the rear sport spring, 208.324.00.04, for the standard one, 202.324.25.04, 1 White 2 Grey, Suplex 19177. This is a much more difficult job than the front especially without a special spring compressor.
Frankly, I'm thinking of trading this heap in!