I purchased my 1999 Grand Cherokee back in 2000 from the original owner with 30k miles on it. It is 4.0 in line 6 cylinder 4x4.
Since then I have driven it 135k miles, having only to replace one water pump and one battery.
This Jeep has never been back to the dealer, since I do all my own maintenance work, just to make sure it is done right.
One upgrade was installing a transmission cooler. I regular tow ATV’s down to Mexico during the winter, and back up to Big Bear mountains on weekends during the summer. I make sure the oil & filter is changed every 3k. Complete transmission flush every 25K, including changing transfer case and differential gear lubes. Radiator gets flushed every two years. Brake fluid every two years.
I use carbon fiber brake pads that last 60K.
I am on my third set of tires (BF Goodrich).
Since this is my only mode of transportation, I have been driving this 70 miles per day back & forth to work 5 days per week.
This is my 3rd Cherokee Jeep with the 4.0 line six cylinder. I average 19 mile per gallon in the city with some freeway driving.
I have had a rear drive line whine since I have owned this car. But I have checked the rear end wheel bearings, ring and pinion gears. They were in good shape, so I just attribute this rear drive line whine as normal for this car.
It is a great car, and I was totally surprised when I had read all these complaints from other Jeep Cherokee owners.