Polyurethane Bushing Upgrade for the CLK55

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.

Continue reading “Polyurethane Bushing Upgrade for the CLK55”

E55 Subframe Bolt Replacement

Replacement bolt for the rear subframe.

The W211-based E55s have a serious design flaw in the rear subframes.  There have been many reports of the rear subframe bolts snapping in two or ripping their mounting bosses right out of the body.

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”

CLK55 Engine Mount Install

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”

CLK55 Project Begins!

I’ve been racing my 2004 E55 for the past three years and now that it’s running in the low 11’s I risk getting kicked out of the track at every event because it lacks a rollbar.  Since it’s my daily driver I don’t want to cut into it so I decided to retire it from race duty and buy another car to use exclusively for drag racing.  This will allow me to be aggressive on the weight-reduction and tuning fronts, as well as add any safety gear necessary as my ETs drop and the MPHs go up.

…it’s a running, driving car and I only paid $850 for it!

I decided to go with a W208 CLK chassis because they seem to be the lightest cars that came with the M113, and I definitely plan on doing an M113k powerplant.  After a few months of trolling the various car-selling websites, I came across this beauty:

She’s a 2002 CLK55 with 219k miles on the clock, but the best part is that it’s a running, driving car and I only paid $850 for it!  Even with shipping from LA to Portland the total cost was only around $1500.  Of course for that kind of money it does have some issues, but they are typical stuff for any MB of this era: needs a battery, motor mounts, rear main seal, front LCA bushings, new tires all around and a good cleaning.  It’s got some other issues with the electronics, but for a racecar, I don’t really care about those too much.

Continue reading “CLK55 Project Begins!”