Speedometer gear

[rgafitanu@gmail.com]

Anybody knows which gear set matches the differential ratio? The speedometer worm gear set in the transmission, the gear set inside the speedometer or both?

Thank you,
Radu

[lurtch]

Hello Radu,

Years ago at one of the PUB events it was explained to me that there are no gear sets in the speedometers.

The calibration is done by fine tuning the adjustment of  a very precise drag clutch on the main shaft.

Other than by  than by trial-and-error, I am not sure how this is done - - -.

Larry in CA

[450sl]

at the transmission all speedo gears are the same ; calibrating is done at the speedo.

[mbzse]

Anybody knows which gear set matches the differential ratio?

The speedometers are different; and each type is matched to the respective differential ratio.

On the speedometer rear, you see a stamped marking, for instance "W=945".
This means for 1 kilometre distance and a 1:4,08 rear axle, one has 945 revolutions.

The table for each type used in our Pagoda cars is:
1:4,08 rear axle diff ratio: 945 rev´s. W= 0,945
1:3,92 rear axle diff ratio: 908 rev´s. W= 0,908
1:3,75 rear axle diff ratio: 869 rev´s. W= 0,869
1:3,69 rear axle diff ratio: 855 rev´s. W= 0,855

[rgafitanu@gmail.com]

Thank you Hans,
That means that I would need a speedo stamped 0.757 to match the 3.27 diff.

[mbzse]

.../... I would need a speedo stamped 0.757 to match the 3.27 diff.

I guess so...  However, such a speedo was never produced by VDO for the W113 Pagoda (nor a 0.801 version for a 1:3.46 diff)
Perhaps a unit from a sedan(limousine) or coupé could be installed (?)

[rgafitanu@gmail.com]

You are right, 3.27 diff's were made only for W108/109 and the V8 W111 (I think).