PeachParts Mercedes-Benz Forum - View Single Post

matsalleh76 · #3 03-26-2011, 10:34 PM

A new Merc steering box has its sweet spot and its point of least play when the steering is centered. I assume this is to allow adjusting/tightening the box to compensate for center wear without significantly decreasing off-center clearance and associated hard-non-return steering.

Here is a write up on steering adjustemnt:

Steering Box Adjustment

The box can be successfully adjusted using simple tools and an educated “feel”. The tendency is to over-adjust the steering box. This will give a very notchy feel in the center and generally heavy or strange feeling steering.

--- Jack up the front of the car with both wheels off the ground so you can feel the play at the steering wheel. The spec is (maximum) 25mm measured at the steering wheel rim with the steering centered, ie straight ahead.

--- On top of the steering gear is a 6mm allen screw with a 19mm locknut. On a RHD car it is buried below the exhaust manifold and is very difficult to reach but it can be done. On a LHD car it is a bit easier.

--- Hold the allen screw and loosen the lock nut.

--- MB steering gears adjust OPPOSITE of normal gears:

--To remove play you UNSCREW the allen screw while holding the loosened lock nut. Adjust in 1/4 turn intervals until the play seems to decrease as you move the steering wheel back and forth to establish the play zone. Look at the front tire while moving the steering wheel and you will get a feel for it.

--Ensure all adjustments are done with the steering centered.

--DO NOT adjust the steering wheel play to less than 15mm or you will end up with tight steering that will not return to center.

--Hold the allen screw and tighten the locknut.

--Recheck the play: it should be 20-25mm at the steering wheel rim.

---Before you start this adjusting procedure, make sure that the play is in the steering box and not in the steering linkage. Check all of the rod ends, tie rods, drag link, idler arm bushings etc: Repair any loose steering components BEFORE attempting to adjust the steering box.

Helpful hint for RHD cars:
Repeatedly inserting an allen key into the adjuster screw is a pain. You can not see it and everything is in the way. Solution: Araldite a 1” cut off section of allen key into the allen key adjuster screw on the steering box and use a 6mm spanner on the cut-off to adjust the screw/hold it in position as you loosen/tighten the 19mm lock nut.

Skewed steering wheels:
Occasionally an alignment shop will adjust toe by shortening/lengthening the tie rods with the steering wheel off center. This commonly happens when the tie rods/draglink are replaced. The result is a skewed steering wheel when the car is running straight ahead. Take it to a good alignment shop, explain the problem and ask them to re-adjust the tie rods for correct toe and a centered steering wheel. A simple job.

Regards,
bobf