I've got an MT75 4x4 gearbox in my car that I bought earlier this year, and have been informed that even though the full 4x4 parts are there, front shafts, front diff and front prop, that the gearbox has been modified to run as a RWD at the moment. I was given a part of the gearbox which needs to be swapped to convert it to 4x4, this is the planetary gear cluster I believe that lives in the transfer box and is driven by the chain.

I've found this pdf online which shows the insides of the transfer casing: http://www.super7thheaven.co.uk/imag...hmt-75-4x4.pdf

Can this job be done with the gearbox in the car? or am I best taking it out to work on the back of the box, with the gearbox vertically?

Thanks in advance.