Working out my diff ratio

[shynsy]

I've got one of my drive shafts off at the mo on my 130S/5 while I was under the car I decided to check out my dif ratio. One out put shaft was locked so it didn't moved. I turned the input shaft and measured the number if turns it took to turn the output shaft one revolution.
I measured around 1.875 rotations of the input for one turn off the output. As one output was locked so it didn't move do I double the number. That would make the diff a 3.7:1.
Tim

[andyelan]

Hi Tim

That would seem correct to me

Regards
Andy

[elans3]

That's the most prevalent, and "standard" diff ratio, although obviously there are lots of others, as Colin used the differentials from the Ford "English" axle.

[JonB]

You can also work this out from the plastic speedometer drive gear in the gearbox - different colours for different diff ratios. Always assuming your gearbox and diff are original, of course.

[shynsy]

You can also work this out from the plastic speedometer drive gear in the gearbox - different colours for different diff ratios. Always assuming your gearbox and diff are original, of course.

OK what colour for the 5 speed 3.7 diff.
Tim

[JonB]

Sorry, I don’t know. I was looking it up but not found it yet. Actually was hoping someone else would enlighten you…

Edit: quick search turned up this : viewtopic.php?t=36413&f=37&start=0#p249714

[shynsy]

Thx