rumor has it that Christopher wrote:
> Craig and Phillip,
>
> WOW! Thanks for the detailed info. SO:
> 3. The speedo seems fixable, but since there is a
> replacement in the trunk (entire instr. cluster), I'll
> simply swap out and verify with GPS.
Some lessons from my experience.
* The odometer gears and speedometer calibration seem
to be model (that is, diff ratio) specific.
I got started on this when I dug into the speedometer on a 300D turbo.
The odometer didn't work. This I have fixed a couple times before, so I
figured it'd be no problem. Well, a former owner had tried to do the
repair with superglue and got the glue onto too many partes. So I took
the whole speedometer assy. from one of the 240 parts cars. It bolted
right in, and was way off. So it seems that rather than changing the
cable drive gear in the transmission to match the diff. ratio they use a
different speedometer assy.! I started swapping parts around between the
two I had and finally gave up and repositioned the needle on the shaft
so that it's correct at 60 MPH. Someday I'll fix it right....
* I think the difference between a 80 MPH and a 120 MPH
speedometer is spring - but I don't have enough data
to prove this.
* When you open up the instrument cluster, it looks like it
might not be necessary to take out all nine screws to get
the speedometer out. Don't be fooled. It's easier to take
out all the screws 'cause the three sectitons sort of
interlock.
* There is one screw hiding in the middle of the rheostat for
the dash lights. Don't forget it!
* A reverstable electric drill works as a bench-top speedometer
drive. I used a 16d nail, cut the head off and filed a long,
square taper on one end. I can chuck this in the drill. Forward
speed requires counter-clockwise rotation of the input shaft
which is why it needs to be driven from a reversable drill.
Full speed on my cheap black&decker drill is about 40 MPH.
* The speedometer needle is press fit onto the shaft. Honest!
It's a tight fit, so be gentle.
> 4. Old instrument cluster (minus bulbs) is free to
> whoever wants to pay shipping once I get it out of the
> car (moved 1 week ago, so arranging the house takes
> priority - or my wife will get pissed. Wife pissed at
> Benz is NOT good). Providing the "new one" is worse,
> then someone can have it and I will be playing with
> springs and magnets!
Have fun!!
Philip, "can't think of anything clever...."
