Tried WD40 trick also, doesnŽt work for me but I left WD40 in only for about 10 mins, IŽll try to leave it there longer and after that upside-down for some time
Anyway, bagman gave me 2 brand new diffs which he wanted to fit on his FS2 (but gave it up), they are impossible to dissasemble (I mean 14T diff gear on both sides - plastic and also metal cover ), I even destroyed a bearing on outdrive as it didnŽt wanted to come off and I needed to shim the diff. Really suprised with such differences in different batches.