Next job on my list is to change the transfer box. Nothing wrong with the one in the car, except it has done 165k miles and I have a new unused one complete with viscous coupling going buckshee. It has been under my workbench for more years than I care to remember and I keep banging my leg on it. Time to do something about it.
Problem is it has the epicyclic gear set for for the manual box. Not to worry, I have an auto box epicyclic gearset to swap over. Easy job I thought .... Not.

The case splits in the wrong place and it looks like all the gubbins has to come out to get at the epicyclic gears. I had a look through Rave and it says remove the viscous coupling first remove the bolts and just split the case. Anyone done it? and what to watch out for?
I was not going to change the oil seals. They are unused and I will be careful not to damage them. There does not seem to be a gasket between the two halves.

Did it recently to change the chain on mine. I take it you are looking at the Overhaul Manual in RAVE and not the workshop manual? According to the overhaul manual you take off the viscous (although I can't see why you need to but it may be obvious when you have it in front of you), prise the oil seal on the input shaft and remove a circlip that lurks underneath and the gearset should just drop out. There's no gasket between the two halves (or on the viscous housing) just RTV. I remembered seeing somewhere that to crack the seal on the VC housing you use a mallet to knock it round so twisting it off which worked and to separate the two halves there's lugs cast into one side that are ideal for giving a clout with your soft faced mallet. So you will need a new input shaft oil seal and in the refitting instructions RAVE says that whenever the transfer box has been off you must replace the gearbox output shaft seal too.

To change the chain about the only bit that didn't need to come out was the epicyclic gearset, everything else did.

Thanks Richard. Got it apart OK. I am following the overhaul manual. I did take off the viscous coupling first as it recommended.

A black square magnet has dropped out. The only place it can go is in the slot that holds the filter tube. Is that right?
I haven't removed the circlip that holds the epicyclic gears. I will do that next.

I will order an input shaft seal, a front output shaft seal, a gearbox output shaft seal and an engine rear crankshaft seal while I am at it.

The magnet fits into a cast slot in the base of the casing underneath the oil pickup tube. See below

All the stuff shown in your first pic has to come out to change the chain rather than being left as it is. What is the difference between the auto and manual epicyclic gearset? The ratios are the same and the gearbox output shaft is going to be turning at the same speed so why the difference?

The splines on the shaft are different. I was going to show them side by side, but I can't get the manual gearset off yet, I don't have long enough circlip pliers.

Ah, so it's obviously a difference in the splines on the gearbox output shaft rather than being a difference between the gearsets. Knowing I was going to be changing bearings in mine while it was apart, I treated myself to one of these https://www.machinemart.co.uk/p/clarke-cht686-10-254mm-circlip-pliers-set/. Not brilliant but did the job.

Swapping the gear set isn't too difficult, we had to do this on a driveway when a mate broke his transfer case (hit a rock while off roading) and the only one we could find straight away was from a manual rather than an auto. The only hard bit was making sure all the shafts were properly aligned when refitting, especially the selector shaft. I don't remember taking of the viscous, but that would make it easier being lighter etc.

The chain can be changed with the transfer case still in the car, if need be. I bit fiddly but doable and saves a lot of time.

Filip

The job is done now, thanks guys. I would agree with all those comments having just done it.
I now need someone to fit it. I don't fancy lying on my back -2 deg C trying to bench press it into place.

Here are the gear sets side by side. They are identical except for the splines.

I now have a new manual epicyclic gear set available, if anyone wants to do a deal or a swap.

We used a transmission jack to lift it and long M10 coach bolts that could be threaded into a couple of the mounting holes and used to align it so we could slide the case into place until the dowels met. Although I've had a TC off before laying on the ground, with the car on a two post lift, the transmission jack and two of us under there, it still wasn't a fun job.

It is too cold and I am too old. I will get someone to do it.