leak from rear of transfer box on 1998 G13BB

Hello

I will attach a couple of photos but hoping the leak is just the seal on the transfer box to rear prop shaft on my 1998 G13BB Jimny.
I was hoping to be able to replace the seal in situ but it seems that the lock nut on the flange plate requires too much torque applied to loosen and tighten up on the car, so the transfer box will need to be removed to facilitate; can someone confirm that removal is necessary please?
Assuming the Transfer Box does need to be removed to do this job, the manual indicates that the oil needs draining and exhaust section needs removing first. I am hoping that the transfer box can be removed with the exhaust left in place and that I can drain and refill its oil off the car?

Any advice/guidance appreciated.      
      

The nut is torqued to 130Nm.
If you make a flange holder tool and you have the space for the long bar, or the arm strength for a short one, you can do it under the car- or a rattle gun should undo it easily once you open up the stake.

Then the seal extracts outwards and a new one drifts into place.

If you must remove the transfer, which is a pain as it involves messing inside the car, undoing wires, more bolts and the mounts, it comes off with the exhaust on- at least mine did on a 2000 M series.

I'd struggle and do it under the car- unless there is corrosion building up between the steel flange on the mounting rubber and the aloominums mounting feet- then it needs the 'box out, and the mount nuts cut off (good luck undoing them) then the mounting feet cleaning and lacquering and new rubber mounts, or the corrosion will eventually shatter the mounting feet.

Thank you facade, appreciate the reply and some hope that this job is achievable without Transfer Box removal. Jimny is outside and rain has stopped play, so a little more time to plan. Please see attached photo. I've made up a flange holder that sits across the top of the flange. When undoing it will be braced with a piece of 4x2 wedged between the holder lip and the concrete floor. I will pack it against the Jimny undercarriage for doing up. I guess it important to stop the flange rotating with rattle gun action, potentially damaging the internals?
I have done my best to release the peaning to the shaft at the top of the lock nut but not a particularly good job. Hoping the 27mm nut will work its way past the remaining grip with the rattle gun action. Assuming that works and I can reuse the nut, I will be able to judge how far to tighten back up positionally with the pean locations on the shaft. Without the rear prop shaft for support, I think continued torque application with a torque wrench will damage the Transfer Box mounts with too much twisting against them, so torquing to a value not possible. 
One more, probably quite silly question, is it possible to replace the seal in situ without draining the oil; I'm thinking not but it would be very handy if it were possible?   
Thank you       

Yes you need to keep the flange from chattering back and forwards, it shouldn't hurt anything as it is chain drive and in 2wd I don't think any gears move, but best to be safe.


Get a big lever on the flange attached to the dexion and you can pull it and the torque wrench together without lifting the transfer box.


It needs draining, if you look at the filler bung, it is half way up the output shaft. You'd have to have the car nearly vertical to drop the oil level at the back enough.

The job is done.
Much of the prep similar to this .............    
GUIDE Rear diff to prop oil seal change 1998 Jimny - BigJimny Forum
I used my dexion piece with another longer piece bolted to it for an effective lever/support - see first photo.
The bolt was way tighter than 94 ft/lbs, so I used a rattle gun to undo.
Important to clearly mark flange position relative to transfer box, so remount in exactly the same position achieved,
Got the seal out easily with a screwdriver and relatively undamaged, save the internal spring.
The flange seal mating surface was not so much ridged as abraded, so I cleaned it up with wet and dry 320 - 800 - 1000 - see second and third photos.
I did not need to drain oil and lost about a teaspoon as about 300ml down already.
Torqueing back to 94ft/lbs was easy with the lever but as can be seen in the penultimate, fourth photo it did not tighten up as far as original. I did add 10ft/lbs but no different. This surprised me as expected it to end up in the same position.   
Once back level I had to add about 300ml of 75W90 GL4, castrol multivehicle, using a big syringe which worked well,
Unfortunately as can be seen by the last photo the increased oil level hit a much more leaky seal on the front of the transfer box, so another seal to do. The third one is much higher up, so I cannot understand how it gets properly lubricated but at the same time unlikely to leak whatever the state of the seal. 
All three of these seals are the same and I am hoping front seal removal will be similar to the rear.
It may be possible to do the third top front seal in situ but I doubt it; will probably leave that one alone:-)     

Well done, thanks for posting the details of your repair.

The nut may previously have been cranked down very tightly indeed, if the final position with correct torque was that different.  I would usually replace a peened nut, but you probably have a decent margin of safety, especially because of the slightly rotated final position.

I agree re the calked nut but it would be very hard to do a proper job of calking it on both sides in situ; the metal takes a fair whack to deform.
I also did not have a part number to find this nut; perhaps you have this?
I suggest that this is the original nut fitted at the factory in 1998 and the torque used was hugely more than the 94 ft/ibs recommended. Has anyone heard of one of these loosening? It certainly would not loosen with factory calking and torque but I guess there is a chance when refitted.
Ideally the flange should have been replaced too but hoping to get away with the refurbed original.
I could really do with a Jimny part number reference manual; is one available?