What does it involve for a 100,000 mile service?

Outside of filters, maybe the PCV and spark plugs if not changed at 100,000 miles with Iridium .

what engine? The fuel filter is in the fuel tank, Spark plugs should be replaced, throttle body cleaned, and the truck generally checked over, battery , belts, brakes, tires ect. Spark plugs, trans fluid, filter, transfer case fluid change, are all due at 100k. You should have the 100K service done. Of course they base that on if you have been following the service schedule. Your owners manual will list all things that are due.

The recommended replacement of spark plugs on your car is every 100,000 miles.

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - EXHAUST SYSTEM - INSPECT

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - FUEL SYSTEM - INSPECT

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - AIR CLEANER/ELEMENT - REPLACE

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - FUEL FILTER - REPLACE

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - SPARK PLUGS - REPLACE

NORMAL MAINTENANCE @ 100,000 MILES (160,000 Kilometers) - TIRES - ROTATE - [Tires should be rotated every 5000 to 8000 miles, and/or at maintenance I or II service intervals.Check tire pressure, thread depth and wear.]

Here is the basic maintenance list for your Jeep:

~ Inspect lights and check tire pressure at least monthly or before & after each trail ride

~ Oil & filter change, chassis lubrication, differential and transfer-case fluids every 3,000 to 5,000 miles or 3 to 4 months - if you have recently crossed through water deep enough to submerge the centre of your hubs, replace the differential fluids as a precaution

~ Underhood belt and hose inspection every 3,000 to 5,000 miles or 3 to 4 months (every oil change)

~ Tire rotation and wheel balancing every 6,000 miles or every other oil change - driving offroad can knock wheel weights off a wheel, so you may need to have this done more frequently

~ Brake inspection every 6,000 miles or every other oil change - if you have rum brakes in the rear, ensure they are cleaned after each trail ride where you encountered deep mud/snow

~ Replace air filter every 12,000 to 24,000 miles or as indicated by inspection - dusty trails can shorten these intervals dramatically

~ Replace fuel filter every 24,000 to 100,000 miles

~ Automatic transmission service every 24,000 to 100,000 miles

~ Wheel alignment check every 12,000 to 24,000 miles or as indicated by tire wear - offroad driving can knock wheels out of alignment, so budget for an alignment every 3 months, then watch tread wear to see if it's needed

~ Cooling system flush and refill every 40,000 to 100,000 miles

~ Belt and hose replacement every 60,000 to 100,000 miles or 5 to 8 years

~ Engine timing belt replacement every 60,000 to 100,000 miles (when equipped) or 5 to 8 years

~ Air conditioning performance check annually, usually in the spring - be sure to run your A/C during the winter for brief period to ensure all hoses and valves stay lubricated and operable

Just a maintenance services, such as oil, filter, air filter, if everything else works fine, don´t do anything else...don´t touch anything !! :-)

This is Toyota's scheduled maintenance for the RAV4 at 100,000 miles...

Replace engine oil and oil filter 1
Rotate tires
Replace engine coolant 2
Visually inspect brake linings/drums and brake pads/discs
Applicable Footnotes:
1) Reset the oil replacement reminder (“MAINT REQD”) light after replacing engine oil, if vehicle is equipped with this light.
2) Initial replacement at 100,000 miles/120 months. Replace every 50,000 miles/60 months thereafter. Refer to "Engine Coolant" in the "Explanation of Maintenance Items" section in the back of this guide for more information.

try Midas or call around to garages

It actually all depends on how you treat your car, any car that someone has put more than 80000 miles in 2 years is questionable, but if you have had no problems and you trust the car keep it.

no not at all, keep what you are doing your doing something right to have a car last that long!!!