decorative center disk piece on tachometer or speedometer

[pj]

This was mentioned in topic=9939.0 where no reply was posted. It's also in the Tech Manual, but just a single line: "A tach problem not related to the cable but requiring removal of the tachometer is when the small grey disk covering the center of the pointer loosens and falls to the bottom of the tach unit." Since I have this problem on my 230SL, it's on my mind and I think I saw a picture (or video?) in a post elsewhere on the Forums of someone else with this. I can't find that right now.

But what motivates me to bring it up now is that Mr. Vallon's website
www.palmbeachclassics.com/restoration.php
shows this problem in the 9th pair of photos.

So I can't help wondering, how'd you do that?

[enochbell]

PJ,

The fix is simple but time-consuming.  Remove the instrument, prise the bezel off (there are other threads regarding this), remove the glass, put a drop of glue on the piece that has fallen off, reassemble.

Greg

[pj]

Hi Greg,
"remove the instrument" makes it sound so easy. But there's no way to get either tacho or speedo out of the dashboard from the front, right?
And to get them out from the back has a long list of pre-requisites, doesn't it? That's why it takes so long. Essentially everything above, below and behind the dashboard has to come out first, I think. And then you might as well combine this with a complete refurbishment of everything back there. This isn't just a project that can be justified by re-affixing the decorative centre piece.
So in the pair of pictures that I mentioned, I wondered if Mr. Vallon had found an easier way.

[enochbell]

PJ, you are correct, this is not easy and it is certainly not quick.  In the pics you reference they show the "before" and "after" with the instrument out of the car already.  There is no short cut.  But if you are going to do it, take the opportunity to replace all the bulbs and clean and grease (if needed) the heat and air control cables.
If you haven't pulled the complete dash at least once you are missing out on one of the real fun chores! :-)

g

[Benz Dr.]

The tach comes out fairly quickly - maybe 10 minuets or less. Putting it back in takes a bit longer because you have to line up the bracket, cable, and ground strap. So for that, maybe 15 minuets.

Removing the rest of the dash gauges can only be done after the tach is removed. This should take about a 1/2 to 3/4 of and hour IF the thumb nuts aren't seized on. Assembly should take about an hour or a little more. The tach and speedo take about an hour each to D&A for a cleaning. We use methel hydrate as a cleaning agent using a Q-tip and a bit of Bosch distributor grease for the gears. Figure on at least 4 hours for this job.


Note: place lots of buffering material against the dash face so that you don't scratch your paint. We remove the temp gauge from the center cluster rather than removal from the cylinder head. That little capillary tube has a way of breaking. :'(

[66andBlue]

... We remove the temp gauge from the center cluster rather than removal from the cylinder head. That little capillary tube has a way of breaking. :'(

Hi Dan,
glad you mention that. I always thought that this is the safest way of getting the instrument cluster in and out. I plan to put a few photos into the technical manual shortly describing this procedure.