I dont have the owners manual for my four runner just wandering how much oil i should use and what oil filter

Is this for the runner rails for the sunroof? You need to use standard grease not oil. Oil is too thin for the job.
Make sure you get the runners as clean as you can before you add the new grease.
Don't add too much grease as it will squeeze out as the roof slides. For Each runner add a lump of grease about three or four times the size of a large pea. Apply the grease to the full length of each runner making sure you get some under the moving end of the glass runners. Then fully open and close the roof 3 or 4 times to load the rollers on the roof panel itself.

I used https://www.google.com to search for a manual but did not find one.

Perhaps contact one of the vendors listed online that might be able to provide a manual or a copy.

Example from google.com:

https://www.littledealer.com/rv/mesa+az/thorindustries+traveltrailer/24140/thor+industries+wanderer+195fg+lite


https://www.littledealer.com/rv/mesa+az/thorindustries+traveltrailer/24140/thor+industries+wanderer+195fg+lite

Here is a diagram for a 1994 pickup. The 4 runner uses the same fuse box, with additional circuits for other options. Fuse 7 would be the same. If you have access to an owners manual, you can reference the fuse box there. Located in the engine compartment.

Go into auto factor and ask for filters they will know what you need ,as for oil then use cheapest diesel /petrol oil you can buy 10/40 20/50 natural or synthetic it doesnt matter which but change it every 6000 m and oil filter every third oil change and you will not go wrong .Dont forget the antifreeze either -all year round leave it in as its to stop corrosion .

BEST TO LET DEALERSHIP CHANGE ENGINE OIL.YOU NEED A DEALERSHIP OIL FILTER.YOUR OIL FILTER INSIDE A HOUSING ON FRONT SIDE OF THE ENGINE. CHANGING YOUR OWN OIL NOT HARD.YOU NEED 9 QUARTS OF OIL LOOK INSIDE GLOVECOMPARTMENT FOR OWNERS MANUAL TO SEE WHAT TYPE OF ENGINE OIL YOU NEED TO USE AND HOW MANY QUARTS.IF YOU DONT CHECK READ MANUAL TO SEE WHAT OIL TYPE AND QUARTS YOU NEED. IF YOU BLOW OR DAMAGE THE ENGINE WARRANTY WILL NOT COVER THE ENGINE.FIRST OF ALL TO CHANGE ENGINE OIL YOU CRANK VECHICLE UP LET IDLE FEW MINUTES TO THIN OUT OIL THEN YOU TURN OFF ENGINE. YOU NEED TO RAISE VECHICLE USING THE FACTORY JACK.USE JACK STANDS. LOOK IN OWNERS FOR CAR JACK LIFTING LOCATIONS TO KEEP FROM DAMAGING ROCKER PANELS. AND PLACE A DRAIN PAN UNDER THE OIL PAN. UNDER THE VECHICLE.YOU NEED A WRENCH TO REMOVE OIL PAN DRAIN PLUG.WHEN ALL THE OLD OIL DRAIN OUT IN THE DRAIN PAN.SCREW BACK IN THE DRAIN PLUG TIGHTEN IT DONT OVER TIGHTEN STRIP THREADS.THEN YOU NEED SOCKET TYPE OIL WRENCH YOU USE WITH A 3/8 RATCHET WRENCH REMOVE OIL FILTER HOUSING.PLACE RAGS AROUND THE OIL FILTER HOUSING TO CATCH OIL SPILL. YOU WILL NEED TO GO TO THE DEALERSHIP FOR THE OIL FILTER AND FILTER HOUSING O RINGS. ONCE YOU GET NEW OIL FILTER AND O - RINGS INSTALL THEM IN THE OIL FILTER HOUSING.LOCATED OIL FILLER CAP ON VALVE COVER UNDER THE HOOD.REMOVE OIL FILLER CAP.POUR OIL IN ENGINE USING A FUNNEL.ENGINE HOLDS ABOUT 8.5 TO 9.0 QUARTS OIL. BUT LOOK IN THE OWNERS MANUAL CHECK HOW MANY QUARTS ENGINE NEED.CHECK OIL DIP STICK OIL LEVEL SHOULD BE ON THE FULL MARK ON THE ENGINE OIL DIP STICK.TO BE ON THE SAFE SIDE BUY 10 QUARTS OF OIL FOR A EXTRA.DONT OVER FILL MAKE SURE YOUR OIL LEVEL CORRECT.OIL DRAIN PLUG AND OIL FILTER TIGHT BEFORE CRANKING THE ENGINE.LOOK IN THE OWNERS MANUAL FOR OIL DIP STICK AND LOCATION.

Should take four quarts of oil. Take a look in your owners manual too.

at 50,000 miles there is really no need. i would wait and save up that money and do a transmission flush 7- 10 quarts of toyota f-type fluid can be costly but a flush removes all of the fluid and garnish along with any fine shavings (normal wear and tear) out of the tranny and replaces it with new clean fluid. normal intervals would be at about 80-100,000 miles. you should be able to find preventative maintenance schedules in your owners manual. if not any repair facility would have it on their computer.

Approximately 4.5 liters

From the Mobil Oil website, all four versions of the 1988 Toyota 4 Runner selected below came back with a recommendation of 10W30 oil. If y the owner's manual came with the car, it should be in there.

From www.mobiloil.com
What's the right oil for my car? Tell us about your vehicle
Knowing the type of engine in your car is important to our ability to match products of the appropriate viscosity to your vehicle. Please pick the engine in your vehicle.
Current Vehicle: Year: 1988 Make: Toyota Model: 4Runner
Please select an engine type. Select Sub Model Cylinders Liter Aspiration DLX 4 2.4 Naturally Aspirated SR5 4 2.4 Naturally Aspirated SR5 4 2.4 Turbocharged SR5 6 3.0 Naturally Aspirated