Quote Originally Posted by fatman View Post
Another question for you guys.
I've read various ARB catalogues,some of them suggest RD128 for disco 2 and some of them RD138 - such a difference also exists for 110 rear with and without traction control,whats the difference?
Thanks
A quick search turns this up:

RD128 = 24 spline, suitable for Range Rover classic, Defender’s
and Discovery’s 1993 onwards. (Previously know as RD56, now discontinued).


RD138 = Defender 110 2003 onwards, rear axle only.
(Previously know as RD57, now discontinued).

RD138 = P38A front or rear. (Previously know as RD57, now discontinued).

RD138 = Wolf rear axle. (Previously know as RD57, now discontinued).


RD128 = May also be fitted into 2003 onwards rear axle and P38A with the addition of a spacer ring. It can then be refitted into an earlier type of diff casing at a later date of required.