I don’t know whether you would consider this an upgrade or a downgrade, but swapping the CLK55’s front rotating assemblies for a set of CLK320 brakes and wheels will definitely make the car quicker at the dragstrip.
I’ve been running the heavy 18″ Mercedes-Benz E55 wheels on all four corners of the CLK55, which look great, but they aren’t be best for drag racing. Each corner weighs-in at over 50 lb, leaving a lot of room for improvement. The factory CLK320 wheels are the hot ticket for drag radials on the rear, but they also make a good low-budget “front runner”. They only weigh about 13 lb each (because they’re forged), and at 7″ wide you can fit a fairly narrow tire on them. I bought a pair of inexpensive V rated 205-60/16 tires that can be used as daily drivers, while still saving a good amount of weight for the track.
The rearward bushings in the front lower control arms of the W208 CLK are known to wear out rather quickly. They are “loose” by design, having an air gap around more than half the perimeter of the bushing, meaning there is only about 2″ of rubber holding the outer shell to the inner sleeve. This not only leads to premature failure, but often leads to vibrations in the car, even when the bushings are new. I’m sure the Mercedes engineers had good intentions, but in practice these bushings have been a sore spot for many CLK owners. You can replace the factory units with aftermarket polyurethane bushings from Powerflex if you want a performance and reliability upgrade.
This typically happens under hard acceleration and can cause a lot of expensive damage to the car. The rear subframe is held in by four bolts, and it always seems to be the rear two that have the problem, never the front two. This makes sense, since under acceleration the rear end is trying to squat while the front end rises due to the torque imparted on the chassis by the drive axles. The front half of the subframe, ahead of the axles, is pushing up into the body, while the rear part, behind the drive axles, is pulling down on the body. With 516 ft-lb of torque available from even the stock engine, those two rear mounting points tend to fatigue and fail when you least expect it.
Adding the large-diameter washers is the key to this fix.
The fix is pretty straight forward, especially if you do it before it becomes a problem. It’s a simple matter of replacing the factory rear subframe bolts with a pair of new bolts with nuts and large washers on them, creating a “sandwich” that is much stronger than the original setup. Adding the large-diameter washers is the key to this fix. They spread the load out over a much larger surface area than the original mounting bosses, thereby making it nearly impossible to tear them out of the body. My car has over 180 dragstrip passes on it, all on sticky Hoosier drag radials, and the bolts have held strong. Continue reading “E55 Subframe Bolt Replacement”→
How can you tell if your Mercedes needs new motor mounts? Well…
I did this simple test by opening the hood, starting the car and putting it in drive. While holding the brake, give it a little gas until the engine starts to torque over. If your driver’s side mount is completely separated like mine, it will be obvious. I thought the engine was going to jump right out of the car!
The M113 and M113K motors in the AMG Mercedes are notorious for destroying engine mounts because they make a lot of torque. Replacing CLK engine mounts is not hard, but it does take a lot of patience, and one special tool. My car happens to be a CLK55 AMG, but this DIY is applicable to the 1998-2002 CLK320 or CLK430 as well. Read-on if you want to learn how to do this job and save yourself about $500 compared to what the dealer would charge you. Continue reading “CLK55 Engine Mount Install”→