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Does anyone know the ratio of the speedometer cable to the axle revolutions?

Wow 74 vies and no responses. Sometimes its just "your" turn. Good to know there's always new things to share with my fellow Pinzer's.

Answer: ~2.25 speedo turns to 1 axle turn.

What relevance does this ratio have? Why is it important unless you are designing a vehicle.
The tire still turns 1 time no matter how large or small the tire. It just goes farther with a larger tire and therefore changing the tire
size throws off the speedo in a stock vehicle tire when changed to larger tire.

If you want to change your speedometer to an alternative mechanical speedo or an electric speedo using a pulse generator, you need to know the ratio to calibrate an electric or match a mechanical speedo. BTW, for reference the right angle gearbox is 1:1.

http://www.isspro.com/installation/IS073.pdf

I think for most folks, the question has never arisen, and therefore they have no clue nor ready answer. From my experience, the electronic versions have alternate methods of calibration, and I expect those are necessary given different tire diameters.

I am surprised that the 90 degree adaptor is 1:1, as I had read previously that it was a reduction gear. But live and learn.

BTW, for reference the right angle gearbox is 1:1.

Well, it was bugging me, but I've found the earlier post which stated that the angle adaptor is a gear reduction:

No question you can run it without the 90. Your speed will be off as it is a reduction for the tires. Add big enough tires and you might not need the reductio

http://www.real4x4forums.com/PinzgauerB ... +reduction

That's a quote from Scott Ingham, who I'd expect to be correct about it.

Not trying to start a fight here, just clarify the answer. Where's Mythbusters when we need 'em?

Well I can assure you that mine is 1 to 1. Obviously it's really easy to check. It's a VDO unit with the #'s 1.0.888 & 33/4616 embossed on the end cap.
Usually 2 to 1 adapters are for Tachometer drive's that aren't off the camshaft.

it would seem if you are correct and your angle is 1:1 that there are different drive boxes. When I removed mine the speedometer read closer to accurate with the larger then stock tires. To me that would indicate that the drive box had some sort of reduction involved or the speed would have read the same with or without the box installed, assuming a 1:1 ratio. Does not really matter as I switched to the electric units so I could calibrate them to read correctly and in MPH.

I know there are various ratio boxes available, but they're usually not angle boxes. I believe there is a box specifically for KPH to MPH. All good things to know.

There must be various units out there. I just chucked one up in a drill and marked the orientation of the chuck and adaptor output. If I counted it right, it was 8:9 ration. It is a right angle adaptor. I'll bring it home and post the part numbers later.

it was 8:9 ratio

Mine might be that as well. It was a fraction off over one turn, but I chalked that up to old eyes.

Mine might be that as well. It was a fraction off over one turn, but I chalked that up to old eyes.

Ahh! I'm dying laughing here. I'd considered commenting that it seemed so small a difference as to maybe be imperceptible without actually counting. But I didn't want to insult anyone.

I counted three times before I trusted my own (old) eyes. Pretty easy to miss.

FWIW, my (old) brain completely forgot to bring home the part number/s...

Interestingly, it's not shown at all here: http://www.pinzgauer.com/parts.php?cat= ... view=03-15 :?: :?: :?: