Owning a Mercedes can seem like more headache then what it is worth. In this topic I hope to explain and inform other owner's on the end's and outs of the front end dynamics on a Mercedes.
You may assume that you will never get rid of the "Death Wobble". Hopefully after reading this topic you will know what to do if the Death Wobble Gremlin decides to visit you.
Let's start off by explaining what all the part's do starting top to bottom.
Turn it left, car goes left, turn right, it goes right.
Between the steering wheel and the rack/gear box is a intermediate shaft.
(some of you may notice a clicking or squeaking sound coming from the area under the dash below the steering wheel when turning) This area never gets grease, try applying some lubricant to the "joint's", it may get rid of the squeak or even help prolong the life of the shaft and joint's.
Gear box/rack and pinion:
This is where the action comes in. Inside of this device are high pressure and low pressure area's. On some ride controlled Mercedes the power steering also controls the hydro ride height. The Gear box/Rack and Pinion contains a set of gears that in turn push a arm. This arm in a gear box type assembly is called is called a pit man arm. A Rack and pinion assembly does not use a pit man arm.
Pit man arm:
This connects to the drag link on the passenger's side of the arm, and attach's to the left inner tie rod end.
Inner tie rod end:
Connected to the Pit man arm and also connected to the adjustment sleeve.
This sleeve adjusted by turning it clockwise or counter clockwise. ( this is what controls the Toe-in/toe-out of the alignment).
Connected on the other end of this sleeve is another tie rod end. This is called the outer tie rod end, because it is on the outer side of the suspension/vehicle.
Outer tie rod end:
It connects to the adjustment sleeve and to the "spindle" of the vehicle. The spindle is what your tire/hub/braking system attach's to.
That is what is included on the Driver's side (left) of the steering suspension, we will now move on again from the Pit man arm over to the Passenger's side (right).
Pit man arm:
This connects to the drag link on the passenger's side of the arm, and attach's to the right inner tie rod end.
Many people believe this to be the cause of the "Death Wobble". There is a way to weld a piece of steel bar stock to it. Some people claim it is high carbon steel, it is not, a simple 3/4 X 1/4 x 1.5' flat stock bar welded in the right spot will do it.
The drag link will not have replaceable joint's, if it has a bad joint you must replace the entire link. Connected to the right side of the drag link is the "Idler arm" and has a machined hole to attach the steering shock.
This is connected to the frame and is suppose to provide support for moving suspension part's. It also attaches to the right side of the drag link and connects the the right side inner tie rod end. With worn bushing's the Idler arm may also cause death wobble.
This is suppose to take the "last" tiny little bit of wobble out of the steering, If you replace it and it does not take the wobble away, don't be surprised, it's meant as a "cherry on top" and will not suppress "death wobble"
Inner tie rod (right side):
The inner tie rod attach's to the Idler arm and to the right side adjustment sleeve.
As with the left side the right side is set up exactly the same from the sleeve to the spindle.
Now that you know what the part's are called in the steering system, let's move onto the suspension.
A modern Mercedes has a lower control arm this control arm attach's at three point's. The first point it is attached to is the lower ball joint. The next two point's are attached to the frame work of the car. These are called control arm bushing's. You have a front and a rear. The rear lower control arm bushing on both side's of the car can cause "Death Wobble"
Mercedes also includes a sway bar in every suspension they offer. A Sway bar will never affect "death wobble" Replacing bushing or the sway bar will not rid you of "Death Wobble" Anything you do to the sway bar will not help you with "Death wobble"
Death Wobble cause's:
Bad/Worn (Rear) control arm bushing's (front of vehicle)
Drag link "flex"
Worn/Damaged Tie rod end's
Worn bushing's (Idler arm) ((They make rebuild bushing's))
I have had customer's tell me that they have death wobble and it turned out to be a simple fix. The problem is most people can not find a good Mercedes mechanic that knows what is wrong.
More to come... With Pic's.
Please don't laugh at my post, I am trying to learn how to use this site.