The manual confusing and at best contradicts it self on several points,
For some reason my English manual is in KM and not in Miles, according to the manual the axle fluid should be changed every 20.000 KM (12.300 Miles) but I found my dealer does it every 25.000 Miles (40.000 KM) and he does not even take the cap off, he just sucks the fluid out through the fill hole and leaves all the dirt and metal bits on the bottom.
The fluid and friction modifier profided by Jeep can't cope with this lack of servicing and you can end up with a sticking LSD at best or a replacement LSD at worst and that will cost you £850 ($1700) incl.; labour (dealer quote)
It is better to do it yourself, you know it is done properly and it is even a bit of fun.
I found that by replacing the axle fluids my self the proper way with the right oil and friction modifier solved all my problems with the rear diff immediately.
I used Redline full synthetic 75W90 for the rear axle and added Redline LSD Friction Modifier.
Hey if it is good enough for a jet engine it is good enough for my KJ.
