Thread: defender diff ratios

AFAIK, all RRC, Disco 1 and all coil sprung LRs are 3.54 from factory. I think the series III stage one may also be 3.54.

Series II, IIa and III normal control are 4.7

Oh, and the way to check ratio and be absolutely sure is to count the teeth on the pinion and ring gear.

Thanks that's great.

mark the prop shaft and the diff housing in a very obvious manner. (I use 2 dots of white paint pen, liquid paper or if Im desperate the nearest auto drivers nail polish)
stick the Tcase in neutral CDL out, jack up one wheel on the axle and turn it by hand.

turn the wheel exactly 2 turns the number of turns the prop shaft completed gives you your ratio.

for the common ratios on landrovers


3.54:1
it will turn 3 times and the mark will be on the other side. (about 9 oclock

4.11:1
it will turn 4 times and the mark will be 40 degrees past the mark

4.7:1
it will turn 4 times and the mark will be about 260 degrees around

if you have any kind of traction aiding diff (other than a selectable locker in which case just make sure its unlocked) you may need to lift both wheels in which case ensure that both wheels complete one full turn.

Nice one - obvious once you know but I would not have thought of that...

Originally Posted by Blknight.aus

turn the wheel exactly 2 turns the number of turns the prop shaft completed gives you your ratio.

Dumb question - If you are counting the number of turns on the prop, why is it against 2 turns of the wheel and not 1?

because of the action of the differential.

if one wheel is stationary the wheel that can spin will spin at 2X normal speed.