Speedometer conversion to Km/h

[Alioking]

Hey

I have a 500E speedometer with tripcomputer that reads in MPH and need to do a conversion to km/h the front plate is not the problem i can get it in germany my concern is how to convert it show the km/h reading

Help is appreciated

 

[gsxr]

You need to change the odometer gears to switch between MPH and KPH.

 

[Alioking]

the gears are to show milage right? What about speed conversion?

 

[gsxr]

the gears are to show milage right? What about speed conversion?

Yes, gears are for the odometer, not speedometer.

I don't think there's any change for speed conversion, other than the faceplate? The needle is in the same place for KPH and MPH.

 

[Alioking]

I thought that too and changed the gears and faceplate but have difference between MPH and KMH and need to know how to fix this difference

 

[gsxr]

I thought that too and changed the gears and faceplate but have difference between MPH and KMH and need to know how to fix this difference

Can you explain exactly what you changed (what old gear teeth count, what new gear teeth count)?

And what the exact problem is now?

 

[Alioking]

I changed new gears for odometer and front faceplates.My problem is when i drive 60km/h (reading inside car ) GPS shows around 40kmh so i concluded that the speedometer is still showing MPH and needs to be converted to KmH

 

[gsxr]

Was the reading accurate before you changed anything?

The speed reading will not change if the odometer gears are switched.

 

[Alioking]

The reading before was in miles and yes it is accurate in miles but i need to convert the speedometer to show the correct speed in KMH. I searched a bit about changing frequency but didnt find alot about it

 

[gsxr]

Is the scale the same on both faceplates? 160mph / 250kph? Stock differential gears?

 

[Alioking]

I put an original mercedes benz front plate to 260 kmh as it should be

 

[Alioking]

Is the scale the same on both faceplates? 160mph / 250kph? Stock differential gears?

The scales are different yes

 

[gsxr]

OK, so new scale is 260kph.

What was the old scale max in MPH?

 

[Alioking]

160. Mph

 

[gsxr]

OK, so I'm confused. If you replaced 160mph with 260kph, those scales are the same.

The reading should not have changed when you swapped faceplates, unless it had been reading incorrectly previously.

 

[Alioking]

Ok so maybe it was before reading wrong, can it be that when i changed the speed dial i didnt put it in place exactly? Or is there a way do adjust the difference in reading? Or is this difference normal?

 

[gsxr]

Assuming the donor speedo was from a 500E (this is important!), you may have put the needle back in the wrong spot. However that would result in the same amount of error at all speeds, i.e. 20kph off at low speed and the same 20kph off at higher speeds. If it's a calibration issue the amount off will be proportional (same percentage) at all speeds.

 

[Alioking]

So you say i should start maybe by adjusting the needle?

 

[gsxr]

So you say i should start maybe by adjusting the needle?

Nope, start by driving with GPS and see how far off it reads in KPH at various speeds. That will give you an idea of what you're dealing with.

 

[Alioking]

E1 = 12 (small 12 tooth gear)
E2 = 48x12 (48 tooth outer gears with small hub gear with 12 teeth)
E3 = 48x17 (48 tooth outer gear with small hub gear with 17 teeth)

Is this right gear combination for E500

 

[gsxr]

E1 = 12 (small 12 tooth gear)
E2 = 48x12 (48 tooth outer gears with small hub gear with 12 teeth)
E3 = 48x17 (48 tooth outer gear with small hub gear with 17 teeth)

Is this right gear combination for E500

The above info is correct for USA-spec cars with the odometer reading in miles.

The gears are different for Euro-spec cars with the odometer reading in kilometers:

Post in thread 'HOW-TO: Replacing Odometer Gears'

Dec 10, 2016

'92 500e - Euro Spec is:

E1 = 12
E2 = 48x12
E3 = 48x12

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