Diff ratio Elite 504 Auto

[makepeace]

Hi all, how does one determine which diff ratio is fitted to the car between the 3.7 and 4.1? Is there a marking somewhere on the diff? Trying to determine which speedo drive to get for the Getrag. Or maybe that is the correct question - out of 18, 19 or 20 teeth on the Speedo drive pinion, which is needed for the Getrag box? TIA

[black eclat]

I think the only way is to remove back casing and count the teeth on the pinion and crown wheel.

There are certainly no markings on my differential.

[EXCEL V8]

On 14/07/2022 at 07:40, makepeace said:

Hi all, how does one determine which diff ratio is fitted to the car between the 3.7 and 4.1?

Loads of videos on You Tube covering this.  You've probably found them by now! 

Pete

[Escape]

Turn a rear wheel while counting the revolutions of the propshaft. 😉

Don't forget the diff will halve the ratio if one wheel is stationary.

Filip

[rjwooll]

I’m pretty sure that all 504s (as they were autos) used the 3.7 diff.