So this morning I put the front of the Jeep up on axle stands and tried to move the wheels.
With the 'box in P and the selector in 2WD I turned the wheel and it rotated freely with the front prop rotating too - the other wheel didn't move. I then put it in 4WD and tried again. This time the front prop didn't move and the wheels rotated in opposite directions. I put it back into 2WD and rocked the wheels and after a clonk it released and was back in 2WD with the wheel rotating freely.
I put the rear on stands and with the 'box in P and the selector in 2WD, I could just about turn the wheel but both wheels turned in the same direction with the rear prop rotating too.
I then but the 'box in N and the selector in N and tried again. Both wheels would only turn in the same direction. I didn't anyone else with me so asked my daughter and her friend to rotate the wheel (safety first) with me rotating the wheel in the opposite way. We couldn't do it.
I dropped one wheel and tried to rotate the other wheel by hand and it was quite hard to turn the wheel.
I've posted some quick vids on youtube to try to show what is happening.
This the front end appearing to work OK. The bit at the end is very cringeworthy so apologies.
Here I'm trying to rotate the wheel with the other wheel on the ground with everything in N and it barely moves.
In this one I'm not sure what the selection is but in between my unfortunate grunting you can hear a knocking sound as the wheel is rotated.
So would the above suggest that there is something up with the rear diff? If the rear diff was locked and the other wheel was down, would I still be able to rotate the wheel. Or is it that the outer gear of the diff is working but the inside gears (the diff bit) aren't working as they should. I couldn't seem to get the rear wheels to rotate in opposite directions (I know the vid shows one wheel down but I did try with them both up)