talipan

For the slotted drain plug on the transfer case I used the large flat screwdriver fitting from my impact driver and turned it with a torque wrench. That can work quite well but it is easy to chew out the inside of the plug if you're not careful. For the raised square it should be 1/2" across so use an open ended spanner or you can put on a 1/2" drive socket upside down and then turn it with a large allen key from the other side. The bigger the allen key the more leverage you can get on it.

Thanks for the feedback. First off it is a petrol engine and being a Series III I have synchromesh on all forward gears. Having never taken apart a gearbox I'm not sure what I might find inside but I have the Haynes manual so I'll have a go at stripping it once it is off. # If it is the layshaft that is worn it may be a case of drawing the old one out and replacing with a new one. Likewise the third/fourth or first/second synchromesh mechanisms could be replaced but the fact that I could drive in all four gears and reverse makes me think that the synchro hubs are OK. The knobbly bits at the end of the layshaft could be what those larger pieces are and maybe some sort of retaining spring or circlip that has also broken up. I'm only guessing though based on the replies I had. I'll put up a new post when I find out in a few weeks time.. Is there anywhere that sells all the internals for gearboxes from new? John Craddock?

It is a Series III. When I last drove it I was able to select all four gears and reverse and drive without any problems. The big pieces in the photo are perhaps a couple of mm across.

I have just drained the oil from my gearbox in preparation for a chassis swap. The main gearbox plug had these bits of metal stuck to it. Can anyone identify what they might be?