diff ratios

[trickydicky]

hi i have just brought an axle from a 200 disco the diff code on the caseing starts whith D90 whitch i can only asume means defender 90 can anybody tell me if it is a defender diff and is there any way off telling the ratio will this diff be any diferant to the rear diff on my 1990 defender?

[Disco-Ron]

As far as i'm aware, most, if not all coil sprung diffs are 3.54:1......

[trickydicky]

thanks mate but if thats the case can you tell me why when my defender is in slippy mud in diff lock the backend has a tendancy to overtake the frontend i thought perhaps it had two diferant ratio diffs on it. or do ya think im just talking out of my exhoust? as i am new to the game.

[Guardian.]

defender and disco are the same unless its one thats been aftermarket changed!, and not sure if the ones on autos are the same, but i think they are.

[Tommo]

disco, range rover, defender, 90/110 all the same (as standard). its only series diffs that have a lower ratio and then 109 and 88" series differ IIRC

[extreme90]

if it was a different ratio, belive me, you'd no about it  :lol:
itll be a 3.54.1 diff
is the rear end passing the front when going down hills ?

[Range Rover Blues]

Aren't series about 4.4:1, you'd know if you had one of each.  All coil sprung are 3.54:1 and I'm told much stronger than the series diff.

You probably get the back end coming past for a different reason, sometimes when I put my lockers in I actually loose control of that axle completely, the opposite to what you'd expect.

Anyhoo, you can buuy other ratios, 3.8, 4.1 and others.

[extreme90]

series are about 4.71 ish
and yep
the ring and pinions are like melted chocolate compared to solid bar choccy 3.54's  :lol: :lol:

i aint lost control yet....i blame poor judgement  :lol: :lol:
ok im going  :lol:

[ian_s]

series diffs are 4.7:1 and i think made of blutack! (except for stage 1 v8s)
anything coil sprung was 3.54:1

[Range Rover Blues]

4.7:1, hellfire I make no wonder they are so slow.

[Bob Ajob]

If you want to make sure on both ratios, take the diffs out and count the teeth.

The crown wheel is the large, the pinion the smaller, for 4.7:1 and 3.54:1, see below:

ratio - crown - pinion
4.7:1 - 47 - 10
3.54:1 - 46 - 13

47 divided by 10 = 4.7
46 divided by 13 = 3.54 (well, just under)

If your two axles have different ratios, you will want to change one of the diffs.

[extreme90]

or
remove the break pads and turn the pinion
3.5 turns of that and the disc should do 1 rotation
but its not needed, you'd know if you had two different ratio diffs fitted, the center diff would have blown up by now

[Range Rover Blues]

Put it in diff lock, jack up one wheel at each and and check they go round at the same speed, but I agree, the samll pile of teeth under your transfer box would kind of give the game away by now :-o

[Tommo]

yeah mark each tyre at a certain point (ie the top) and spin them like 5 times and check the marks still get to the same point (ie the top) at the same time