Questions on Terrano differential, transfer case and drain/fill plug remover tool

[Patrick T]

Hello All!
I have an early 4wd Terrano (WD21) with a Z24 engine. I apologize as the only 4wd vehicle i`ve owned (and still do) is an old misubishi-willys, japanese version of the cj3b, so i`m not thoroughly "modern" and still know little about 4wd`s in general.

So on to my questions: 1) Is there anyway to know if my front diff is the R180A or the R200A? And if my rear diff is the H190A, the C200, or the H223B?

2) I wanted to replace the transfer case and differential oil. The rear diff is easily visible and so easy to change. But i cant see the front diff. I assume its hidden by some kind of gravel plate? If so, is the plate easy to remove?

3) As far as the transfer case, i believe i located what would be either the drain or fill plug (cant remember if it was directly below the transfer case or higher up behind). In any case, i only located one plug. For good measure, could anyone pls tell me anyway where both transfer case plugs are located? Pictures would be even better .

4) Anyone know the exact size of the square shaped allen tool used for removing the fill/drain plugs (is the hole in fact just a plain square hole)? I asked as they are impossible to get over here in my part of the world and so resorted to a machine shop to make one for me (importing one would take some time, not to mention the exorbitant taxes i would have to pay over here), cheap labor over here . Thank You very much! P.S. Pls dont get confused by the year of my terrano, these are really just the first generation terranos.

[Patrick T]

Ok, no answer yet.

Anyway, i decided to have the 4 sided allen key made from the shaft of an old shock absorber i had lying around. Using my vernier caliper, i had the allen key made measuring 13.7mm (on all sides of course). I assume 13.7 is approximate since my caliper must be somewhat worn by now. I`ve only actually tried it on the rear diff fill/drain plugs, and it fits nice and snug. I havent tried it on the front diff as i still have to remove the bottom plate??, but i assume (hope) the plugs are the same size. I then tried it on the transfer case plug (dont know if its the fill or drain plug), but it did not fit! I measured it and its approximately 13.7mm.

So anyone have answers for my questions #1, #2, and #3?