Crown Wheel & Pinion Ratio Identification

[mazdatenfive]

Does anyone know how to ID the various Mazda MX-5 crown wheel & pinion ratios.

I guess the number of teeth on each part is the starting point.
Would anyone of you knowledgable people like to elaborate on this. EG 4.1 has xx number of teeth on crown wheel & pinion has xx number of teeth etc etc.

[greenMachine]

Is it in the car? If so, jack the rear up, secure one rear wheel, turn the other rear wheel once (or any number of complete, exact revolutions of your choice ), and count the revolutions of the propshaft. Can do it the other way if you like (turn prop shaft, count rear wheel revolutions). You will need some precision to ensure the result is accurate, which means a couple of people, and a tape measure to measure circumference of wheel and get accurate measurement of part revolutions.

If it is out of the car, yes just count the teeth and plug them into your calculator (big number divided by small number) if metal arithmetic is not your strength

[mazdatenfive]

Thanks greenmachine, that is some very useful information to ID ratios but only for the gears in my possession.

I am also hoping someone can supply the tooth counts for the various ratios so as to confirm diff ratios for prospective purchases.

[greenMachine]

Oh.

Sorry, can't help. Have you tried the big board, I'd be surprised if someone hasn't done this?

[Rob E]

Here ya go

http://solomiata.com/RingandPinion.html

[Matty]

http://solomiata.com/Drivetrain.html

[mazdatenfive]

Great work Rob E & Matty, that's exactly what I'm after.