Brake Lines - I inspect them every 6 months and first sign of cracking they get changed. I accept the outside cracking is not the full story but cracking is the first thing I see.
How often you change lube depends on how you use the Jeep.
ENGINE OIL/FILTER - every 3000 miles (6,000 miles on highway) or when oil becomes dark/with fuel smell or 12 months in cold climate, 6 months in hot. I do not use synthetic oil, it will be changed before I see the benefit. Now, if it was my XJ Cherokee DD it would be synthetic and every 6 months as it drags its way through tropical traffic every day. I have seen plenty of vehicles here where they change the oil but not the filter, lazy heathen.
BALL JOINTS (GREASE) - 3000 miles upper, 1000 lower if you drive it a lot. When you do uppers also check/repack front bearings.
CROSSJOINTS and OTHER CHASSIS. every 3 months. Leave it and you will regret it.
AIR FILTER - 15000 miles -- K&N clean and oil as necessary. I tend to take them out and have a look every 6 months, if filthy they get replaced.
REAR GEAR OIL - 10,000 miles or 6 months. Again it depends on how you use the Jeep. If you do trails and water then 6 months is about right IF the breather is correctly fitted. You may find that water gets in otherwise and I would not leave it 6 months. If all the Jeep does is highways and sits there then easily 2 years.
FRONT DIFF- every oil change especially if you have low gears/locker. If not and it is a highway queen then 2 years.
TRANSMISSION OIL - 20000 miles or once a year if used on trails, If used on highway then 2 years.
AUTO TRANS FLUID. I tend to hav ebad luck with auto fluid so I change every 2 years.
TRANSFER CASE - 20000 miles or once a year, if used on highway then 2 years.
COOLANT - 30000 miles, but I change no more than every 2 years.
SPARK PLUGS/WIRES/DIST CAP/ROTOR - 30000 miles or as needed. I find the spark plugs last 2 years, the rest depends on quality. At every oil change, pull plugs and check wires for resistance, cap and rotor for carbon/burning.
SHOCK ABSORBERS - hardly ever but they shoud be changed every 50,000 mile son a road vehicle as they lose the ability to track the road surface at speed.
I use ordinary mineral based oils and lubes, nothing fancy but a reputable brand as it is less expensive than fancy stuff and I want to change it from time to time. For chassis lube I use some ordinary chassi grease, same for wheel bearings. With greasing it is more important to regularly grease than what brand it is.
Same with the oil filter, a medium cost reputable brand and change it often.
Batteries here last about 2 years. The Cherokee gets an electrolyte check every month, the CJs about two months. The Cherokee gets very hot and the water evaporates relatively quickly out of the battery.
BagusJeep lives in Bali.
1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE