That depends on year and engine size. Check you owners manual or ask a new question with more info included.
Yes, it is part of the oil pump.
The best oil viscosity for a 1989 Jeep Cherokee Laredo is 10w-30. This type of oil is designed to give a good balance of lubrication and protection.
I have a 1991 a 1992 and a 1993 jeep wranglers and all take 6 quarts of oilwith a new filter installed. I use 10-40 weight oil in all mine its good for all yearand all weather driving. Be sure to change every 3,000 to 4,000 miles if you loveyour jeep like I do. Jeep people are the coolest but you have to not have aproblem with getting it dirty. Jeeps like dirt and mud.
10w30
10w30
10W30
10w30
10w30
10w30
10w30
5w30
10w30