Strange oil color in the front diff.

The amount of grease that is inserted into the axle housing, oh by the way "challis" is a soft silk and worsted fabric, is 100grammes per side, not a small amount as has been mentioned. This amount is inserted after the axle shaft is placed approx. halfway into position. This means the shaft is unsupported and the grease, having been applied to the rear of the housing will see some of it pushed past the seal as the shaft is pushed all the way into position. Another point is that an 08 Jimny will not have seen a Suzuki franchise for many years and as it has been pointed out the technicians who have maintained the car over the years may well have exceeded the recommended amount of grease placed in the housing and then entered the shaft after applying this extra grease and by so doing pushed even more grease into the main body of the casing.
Now that we have more info. concerning the previous owner and it has come to light that he liked to play in the mud, it has been proposed that water entered the main casing and mixed with the diff. oil but the new owner has said that he checked the axle breather and said that it was working correctly.
So how was the water getting in? If the breather was ok, it wasn't getting in that way so that leaves the knuckle seal and if water got in here it would mix with the grease before it could enter the axle casing and thence into the diff. One thing that wasn't mentioned was whether the oil level was over the recommended level ie did it gush out when the fill plug was removed?

Roger

Absolutely agree with the above!

My factory breathers were also working as designed, but after a couple of trips including deep water / mud my diffs were contaminated.

Yes the spring breathers are supposed to close themselves when you hit water, but it the diffs are hot they will still try to ‘breath’ through the springs and inevitably suck in some water, and it doesn’t take much water to make the contaminated milkshake you see.

Replace the diff oil, and if you also want to play in water/mud that is above the axles then invest in fitting some proper breather pipe.

I am going to make an assumption here and that is that the design of the Gen.3 is basically the same as the Gen.4.
With that out of the way I can advise that the official Suzuki workshop manual clearly gives the added grease as weighing 100 grams and this amount is added to the housing after the shaft is entered into the housing but before it is fully pushed into position. This system would allow grease to bypass the seal.
Yes, I agree that the standard axle venting system leaves a lot to be desired and I replaced it on my LC, and if in the future I decide to be adventurous with Tonka I will fit a suitable system to ensure the local water stays outside and not inside, but the author advised that when he bought the car the vents were working.

Roger