lock right 1510 LR

Hi all , I am new in this forum and need some advice ,
I am having problem with new installation of lock right 1510 at rear axle , I have done the installation by myself after reading the instruction and some internet video’s ,
My jimny is 1999 automatic gear box
The issue is that it is not releasing while it have to , while turning the two wheels are locked , no sound of clicking
I have used one thrust washers at the side gear ( the thin one ) ,and I have done this from the instruction : “ If the block is too tight and the long shaft will not insert, use a belt sander or grinder to carefully remove about .005-inch” ,I am not Sure if it was .005 – inch , I have just remove the amount of surface until it fits free ,

Need some advice from this point ?
Does anyone know if there is size different for the differential case from samurai to jimny or from different years of the jimny ?

Please advice
Thanks
Meir

Cant help with the lockrite, but I do know that the axle casing into which the diff fits is different through the years. Its sometimes necessary to cut a grove into the axle casing for the donor diff crown wheel to fit into when changing between them.