Grinding noise while driving at low speed heard at <45 mph, but wheb brakes are applied the grinding noise turns into a low grinding noise.

SOURCE: HAVE 2004 JEEP GRAND CHEROKEE,HAS LOW WHINING

the whinning noise is definalty a signiture of the bearing, and they do on occasion start making the noise long before other systoms of a bad bearing appear. There is really nothing else in the suspension that moves in a manner to cause the whinning pitched sound, other than the axel, but there signature has allways been a clicking around turns, so id definatly look cloesr at the bearings......good luck

SOURCE: 94 jeep grand cherokee laredo v8 5.2l automatic.

You can check fluid level by removing the rubber plug in the cover. Fluid is full when on level ground, it is just at the edge of the hole (or very close) if you are already getting noises out of there, you can remove the cover and inspect gears for wear or breakage. If you find a large amount of metal debris in the lube it tells you something bad is going on back there. Although rebuildable, it's not a home job...requires exact settings in order to operate properly. You can find good units far cheaper than even a gearset costs in any scrapyard. to match ratio, count the teeth on the ring gear and the pinion gear. the replacement MUST have the exact same number. Before swapping diffs, check all back there to make sure noise is not from somewhere else.

SOURCE: 2004 Jeep Grand Cherokee loud grinding sound when braking

It would be hard to guess at you electrical problems but get your brakes checked.It sounds like your pads have worn down to metal on metal.Very dangerous and can get expensive to fix the longer you leave it.A visual inspection can tell within minutes if this is the problem.If this isn't the problem the 2nd most common thing is a loose brake caliper or caliper mount.A friend with some mechanical knowledge will be able to check the brake pad thickness very easily and quickly with just a torch.Hope this helps

SOURCE: my 2000 jeep grand cherokee wobbles uncontrollably

mine had the same problem, shaking uncontrollably. It was the track bar. I got it replaced, and no more problem from it.

SOURCE: makes grinding noise when turning on low speed

sounds like bad power steering pump