can someone please enlightem me how i go about working out the A) ratios of the 1-4 gears in my ford box and B) the ratio of my diff.

Many thanks

Colin

colin,

checkout quaife's website, they have a calculator program you can download that will tell you the speeds in each gear etc. you can input different gear ratios, tyre + wheel sizes and dif ratios etc.

Ned.

blinding, cheers Ned,If im still bamboozled i will be back!

Colin

Ned
Using Quaifes calculator, 30 mph @ 1236 rpm & 100mph @ 4121 rpm

looking forward to seeing how acurate it is..

i'm guessing it only works on the figures given and works it out, mechanically speaking.
ie don't know if it takes into account rolling resistance, air resistance, mass/loading of engine etc etc.

Ned.

There is a splendid gear ratio calculator on Peter Ogden's site at

http://www.locost7.info/

Look for the side link for GearCalc.

This is an interesting site as well (and Peter's a nice bloke!)

cheers,

David

Forgive me if I miss the point but Colin didn't you ask how to find out the various ratios? Don't these various calculators rely on you giving them those same ratios?

Anyway to answer the one about diff ratio (which I think is what you asked) take off the back plate/cover then carefully count the number of teeth on both the crown gear and the pinion gear. Divide one by the other and that's the ratio. I can't remember which by which but it should be obvious by the answer you get. BTW, it's better to jack up one wheel and get someone else to slowly turn it whilst you count teeth.

HTH.

[Edited on 6/8/2003 by andyd]

quote:

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Originally posted by andyd
Forgive me if I miss the point but Colin didn't you ask how to find out the various ratios? Don't these various calculators rely on you giving them those same ratios?

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Failing that if you know what car your bits came out of, pop down the library and have a look in the haynes book of lies, that's how I found the ratios for the rover SD1 manual box.