This information was put together and edited by David, much of the text was provided by Shaggy and found in the archives of the Baby-Benz forums.
A-class steering column inspection
To confirm movement in the lower joint, take hold of the shaft, (under the bonnet) and feel for movement. Then move the steering wheel 90° and again hold of the shaft, (under the bonnet) and feel for movement.
A-class steering column replacement
1. Remove the instrument cluster; seven screws to remove only on pre facelift models the first two are under the panel below
the instrument cluster one each side of the steering column remove these then remove the vent knob on the right (a sharp pull normally does it) then pull the panel towards you and it will unclip this will reveal the four screws that hold the instrument cluster and surround remove these and pull the instrument cluster surround towards you it will come away the instrument cluster will now lift up but you may require some force as the clip at the back can be quite tight be sure when lifting that you keep an eye on the wiring at the back the instrument cluster may have screw seven holding it down at the rear. Check for this before giving it a tug. Rebuild in reverse order same action for changing relevant bulb
2. Locate the right hand kick panel and in the centre you will see an oval blanking plug remove this and undo the Phillips screw that holds the trim on next remove the door seal from around the area of the kick panel it usually just pulls off and you will see two clips that secure the kick panel to the lower a pillar remove these clips they usually prise away from the body then slide your hand down the back edge of the trim and pull this towards the throttle pedal area this usually take some force and you may have to press the pedal down to get enough room also there is a third metal clip under the side trim but to remove this trim is a pain and the clip is normally removed when the alarm is fitted at the supplying dealer.
3. Pull off the black trim around your light switch (it does come away honest) and remove the light adjuster switch from the surround (clip top and bottom of switch)
4. Remove your lower panel there are approx 11 screws under your dash on the left side of the steering wheel you will find 2 screws remove these then on the right side you will find 1 small screw that holds your bonnet pull lever and 2 screws that hold the housing with the diagnostic connection in remove all of these and pull the housing towards you it will then drop down then remove the 2 screws from the light switch last of all remove the four remaining screws from the top of the trim including the one near the A post the trim should now pull down and towards the door. Poke everything that is hanging through their various holes and take the trim away.
5. Next make sure that your wheels are straight ahead and remove the ignition key and disconnect your battery.
6. Disconnect your air bag you need the long thirty torx and if you feel around the back of the steering wheel you will feel 2 holes insert your torx into one of these and locate it in the screw and undo then repeat the operation on the other hole and the air bag should come away disconnect the connecter this should just pull out and remove the airbag unit this should be placed metal side down and out of the way.
7. Steering wheel, disconnect the 2 horn wires and undo the 10mm Allen key that holds your steering wheel on then remove the wheel unit.
8. Contact ring, next remove the 2 screws that hold the contact ring in and remove the ring (this should come away as one unit do not try to turn this unit once removed and ensure the wheels are straight ahead when refitting) then undo the three screws that hold the cruise control (if fitted) and the indicator stalk in and remove both of these you will see the connectors for these which you will need to remove from there holders on each side of these connectors there is a plastic flap that you push towards the connector with a small screwdriver whilst pulling the connector towards you (do not try to push them away from you as they will break off and you will not be able to refit them)
9. Now you need to remove the transponder coil around your ignition switch if you look inside your steering column surround where your ignition switch is located you will see the clips that you need to lift whilst pulling the transponder away from the switch this does come away with a little bit of force be careful as this has a wire connected to it. Do not attempt to remove or cut this wire, as you will no longer be able to start the car if this wire is broken.
10. Now remove your steering column surround this will pull towards you (note if you have an adjustable column you will first need to remove the handle on the adjuster lever this is done by removing the screw located through the handle and then pull the handle off) the surround will pull away over the steering ignition barrel it is just a bit tight and when refitting make sure that the lower surround locates on its peg.
11. Next remove wiring multi-plug from the ignition lock and ensure that the wiring loom is free to move away from the column and all multi-plugs are disconnected from the column.
14. Now with the column out you will need a drill and a punch. Locate the steering lock and inspect it. Check how it mounts onto the column, you should see a roll pin that goes into a blind hole. You need to select a suitable sized drill to drill a hole in the opposite end so you can insert a punch into the drilled end and knock out the roll pin to release the steering lock mechanism.
- When fitting this to the new column you will need to turn the new column until the slot in the column lines up for the steering lock otherwise you will not be able to refit the lock.
- Also when refitting the column, make sure that you line the 2 marks up on the splines (usually paint marks) when fitting the two parts of your new column together.
- One last point if fitting an adjustable column, please make sure before fitting that you remove the production plate from the adjusting mechanism before fitting. (It is just a flat plate with a large hole in it)
- Also after you have finished the job when you start the car you may have three warning lights on all you need to do is turn the steering full lock either way 2 or 3 times.