W111 Headlight Restoration

My 250SE was sporting the stacked style of headlights, which are quite popular on these models.   Personally, I prefer the original type.    I had some original lights, but needed to restore them before they could be fitted to the car.

The wear parts of the headlights are the reflectors that dull and rust over time, the gaskets that crumble (as can be seen above) and obviously the bulbs.    The housings are generally ok, although they can be bent if the screws are tightened too much. The fasteners that hold on the lens can also break.

The reflectors and gaskets are still available from Mercedes, although they have become very expensive.   At minimum you’ll need the main reflector and the rubber gasket that seals the lens to the housing, and the gasket that seals the housing to the body of the car.   The first gasket is important to stop water getting into the headlight and ruining the reflector.   The second is important to seal the headlight to the car as this is a major rust trap for the 108-112 Mercedes.    In addition, you can also choose to replace the fog light reflector.   It is probably possible to also replace the reflector for the indicators, although I did not attempt this.

The picture above shows the difference between the new and old reflectors, and the headlight on the right was probably the best of the ones I had.   Make sure you buy the reflectors from a good source.  I got my foglight ones from an online place. They are a copy that does not fit particularly well and is missing the rubber mounting parts.   The main reflectors I got from MB Spares and not only were they a perfect fit but they came with all the mounts needed.

The old reflectors are quite easily removed.   They are held in by rubber mounts, and they just pull off.   Two of those mounts are adjustable so the lights can be adjusted correctly and do not dazzle other drivers.  The bulb assemblies just screw off also.

As can be seen on the photo above, the new main reflector is mounted from the rear, and there are holes for the bulbs that need to be inserted.   The foglight reflector is mounted from the front.  To get the most out of the lights, halogen bulbs can be used, but they need to be special ones that have old style connections.   I bought mine online.

The right bulbs will only sit in the reflector a certain way due to a notch that helps you locate it.   The original bulbs for these cars are 45w.   This might seem quite low, but I personally would not go higher on a 50 year old car unless I had re-wired the headlights and were using relays instead of sending all that current through the switch.    The small bulb also needs to be put in place before the bulb assembly is re-attached.

The lower reflector is fairly similar to the upper one except that the bulbs are more standard.  At this point it is worth hooking up the light to test it before the lens is fitted.

The first gasket is put on the front of the light in the channel so that the glass lens is held against the gasket by the retainers.   The retainers are probably the weak point of these lights as they crack over time.   One of mine has broken off so I will need to repair it at some point.   Were the car a daily driver this would be more urgent.

The rear gasket is placed against the light housing before it is screwed in.   The housing metal will bend if these screws are over tightened.

The old lights are quite easy to remove.   There is a single screw to remove the frame, and then four screws to remove the light.   There is also an attachment point for the frame that sits at the top that must be removed as well.

From there, the new headlights can be attached and tested.   For those of you who are indecisive, you can have one of each on your cars.

The job is almost complete for me.  I need to repair one mounting point for the lens on the passengers side, and get a new foglight bulb on the drivers side.

W111 headlight restoration is a job that can be tackled at home and does not require special tools.  The process is the same for all related cars such as the W108, W109, W112 etc.