Refurbishing a W124 instrument cluster – Part 3: Changing the housing

In this series I am refurbishing my W124 instrument cluster.   In the first part, I removed the cluster and lubricated the speedo cable.   For the second part, I repaired the W124 outside temperature display.   Now I am focused on my instrument cluster which is afflicted with the dreaded white spot disease.

While I was in the UK for work in January, I purchased a good used W124 instrument cluster housing.   My plan was to transfer my instruments and electronics to that new housing.   The actual gauge faces were in good condition.    It’s been on my to do list ever since then.  I didn’t know about the bitumen stuff that covered my cluster back then, but this has the added benefit of fixing that too.

The new housing is almost perfect.   It has no white spotting, and the glass is in great shape.  It still has the rubber blocks that help the cluster stay in too.   The only slight imperfection is there is a little bit of melting around where the dash lights go.   A previous owner of this cluster probably used the wrong bulbs.   It is also ever so slightly different, with a ridge at the bottom.

I had already removed the cluster and the outside temperature display which is the first step.    Unlike on the W126, where its easier to remove the instruments individually, I found on the W124, it sort of all has to be done together.   I first removed all the screws that hold in the speedometer and rheostat.  However, this didn’t really want to come out until I removed the screws that hold in the left and right circuit board and instruments.  There are two on each side.  For example the little circuit board on the top left is underneath the silver housing for the clock and tacho.

A lot of people at this point would paint the needles on their instruments.   I personally don’t like to do this, as the needles should be the same colour as the max RPM marks and crosshatched section on the speedo face.   My hand is not steady enough to repaint those, and freshly painted needles just show up those sections unless they are done too.

Getting the instruments in the housing was not hard, just a bit fiddly.   I found I had to start by clicking in the small circuit board above the clock/tacho and then slowly guiding in the other instruments.

The other thing I had to change was the backing for the warning lights.   This cluster had obviously come out of an Airbag car.   Its a simple matter of using tweezers to pull out the backing strip and put in the correct one for my car.   These backing strips vary quite a lot, depending on the car they came out of.  Interesting that the font changed a bit.

Just a simple thing like changing the W124 instrument cluster housing has made a huge difference.   As it sits in front of you as you drive the car, I think it’s a worthwhile improvement.   The white spot is gone, the glass is clear and I can see my instruments properly.   When I couple this with the repaired outside temperature LCD, its going to be a big improvement.

The final step for this process is going to be reinstalling and testing the instrument cluster to make sure I have it all back together properly.