Speedometer / Odometer in KM

[dirk2602]

What does it take to make a Euro tii speedometer (220 kph / W=0.80) work correctly in a '73 US tii.

Thanks.

[Guest Anonymous]

What does it take to make a Euro tii speedometer (220 kph / W=0.80) work correctly in a '73 US tii.

Thanks.

It is not clear to me exactly what you are trying to do. Change the face of the speedometer from KPH top MPH or recalibrate the device for a different axle ratio.

All of the speedometers are interchangeable. For the speedometer to read accurately, it must be matched to a specific axle ratio. Thus, if the Euro speedo was originally fitted to a car with a 3.45:1 rear axle ratio, you should be able to move it over to any other vehicle that has the same 3.45:1 ratio. If you are asking how to recalibrate the speedometer to work with a different rear axle ratio, this requires disassembly of the device.

Changing the faces of the instrument is not difficult, but it requires a little dexterity in removing the needle without breakage and without disturbing the set of the pin onto which the needle is attached. Jewelers or watchmakers tools work best for this. Using simple math it is not difficult to convert KPH to MPH, in which case you can make stickers to affix on the glass covering the speedometer. It will look stupid, but it works.

[dirk2602]

Thank you for your response Wim. I purchased a 220 KPH speedometer in Germany and would like to install this on my US tii. The rear axle ratio on the European tii's (72/73) is 3.45 according to the BMW literature. The rear axle ratio on a US tii (72/73) is also 3.45. So basically, if I understand you correctly, it's plug-n-play ?

Thanks.

[jgerry2002]

I believe US tii's had 3.64s... with the exception of a few early cars.....

[JohnS]

My 1973tii came with a 3.64 rear end stock.

This from another thread:

3.45:1 diff -- W=1.24 speedo

3.64:1 diff -- W=1.297 speedo (W=1.30 is close enough)

3.90:1 diff -- W=1.39 speedo ('76 49-State 2002)

3.91:1 diff -- W=1.393 speedo (E21 320is LSD)

4.10:1 diff -- W=1.4 speedo (1.461 calculated)

4.11:1 diff -- W=1.4 speedo (1.465 calculated)

4.38:1 diff -- W=1.559 speedo (calculated)

http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/p,656384/highlight,speedometer/#656384

[dirk2602]

My 1973tii came with a 3.64 rear end stock.

I believe US tii's had 3.64s... with the exception of a few early cars.....

It is possible that my '73 tii (mfg date 09/72) has a 3.64 diff ratio.

The early 72 US and Euro sales brochures both state 3.45 for the tii and 3.64 for the non-tii, and in the 74 brochures these number changed to 3.64 and 4.11 repectively.

The Euro tii speedometer is a W=0.8 (800 rpk) and the US is a W=1.297 (1,297 rpm, i.e. 811 rpk)

So hopefully it is indeed plug and play without re-calibration