Took the PTO cover off my 90 and the disco I bought a few weeks ago.
The 90 had little gack around the splines:


However when I rotated the brake drum I could see a bit of play in reference to the lines (i.e purple would turn through about 3 degrees then green start). This didn't seem to bad, although it looks like I should get the oil splasher I guess.
However I couldn't rotate the green gear by hand at all.

I took the disco off and saw at 192k miles what I kind of expected

loads of gunk. However putting my finger between the shaft and the gear I couldn't feel that much play as they turned. Certainly no more than the defender.
However I could rotate the green gear by hand. I presume this gear is the output gear which is cross drilled on some.

I checked the play by:
1) chock front wheels.
2) jack one rear wheel
3) take handbrake off
4) observe the shaft and gear will turning the hand brake drum backwards and forwards

I am tempted to think that the disco transfer box centre diff has loads of play for me to be able to turn the output gear a bit whereas no way was the defender one moving.
For some higher res phots go to def and disco photos

Is it worth me splashing out on the oil splasher plate for both, the disco looked horrible, but there really didn't seem to be that much play, I am going to try and get a second opinion over the next few days....

Steve you can take the input gear out in situ for assement , undo the two large posi screws on the back bearing cover , romove cover and juggle the gear out ,IMHO seeing that much gunk in the gear I would deffo take the gear out and check it .
Jase

Cross drilled input gear about £45 from Ashcrofts.

thanks for that, I wondered if the large screws were what were stopping me form getting it out. I was so full of oil having done the oil change on the defender and also accidentally draining the gearbox that I couldn't be bothered going to the workshop to look at the manual.

I'm worried that it may be supporting gunk .