Thread: Rear Axle Drive Ratio

G'day all!
I have a Salisbury Ex-Mil 24-spline rear axle with drum brakes and, being in process to convert to discs, got myself a 2001 Defender Salisbury rear axle to replace the old unit. Is there anything that will tell me if the drive ratio of the diff of the replacement differs (pardon the pun) from the original one?
Cheers

Originally Posted by 91ramjet

if you were unsure whether they both have original crown and pinions you can calculate it by spinning the hub or wheels of both of them once and counting the rotations of the pinion. eg if 3.54:1 the wheel will spin once and the pinion 3.54 turns.

Hi 91ramjet

Close, but your answer needs a little more info.

With gear box in neutral, jack one wheel up (so the other side can not move), turn wheel around twice (that is because of the differential action), easy way to then check is to start with the valve at the top and count off the two turns from that point.

Using a suitable reference point on the rotating pinion (grease nipple in the universal joint), then count the number of turns the pinion does as the wheel does its two revolutions.

If it is a 3.54:1, the pinion count will be 3.54 turns, if the crown wheel and pinion ratio is 4.7:1 then the count would be 4.7 turns .
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