4th Gen 4runner Diff Fluid And Engine Oil Change For Beginners

Changing the oil and fluids on a 4th Gen Toyota 4runner is a pretty easy job. If you know how to use a ratchet and aren’t afraid to get a little dirty, you’ll be able to change both the motor oil and differential fluids yourself.

The beauty of the 4runner (especially if yours is lifted) is that there’s plenty of room to work underneath without needing to jack it up or drive it up onto ramps. Just slide yourself under and go.

Products needed for a V8 4runner oil and differential fluid change:

• Motor oil (6 liters)
• Oil filter
• Engine oil drain washer
• Drain pan
• Funnel
• Synthetic gear oil (6 liters)
• Fluid pump
• Replacement fill and drain bolt washers

V8 4runner engine oil capacity

The owner’s manual states that the 4.7 V8 requires 6.2 liters (or 6.5 quarts) of oil. Personally, I put 6 liters in every time and call it good enough. I’d rather have it register a little lower on the dipstick than overfill it. If you feel better adding the exact amount that Toyota recommends, go ahead and buy that extra liter.

If you own a different model of 4runner, this article has a table that features the oil type and interval for every generation.

4th Gen 4runner differential and transfer case oil capacity

Toyota states that the front differential requires 1.4 liters (or 1.5 quarts) of oil and the rear takes 3.05 liters (or 3.2 quarts). The transfer case requires another 1.4 liters (or 1.5 quarts). If you add that all up, you’ll need 5.85 liters of gear oil to change the front/rear differentials and the transfer case.

Best oil for the 4.7L V8 (2UZ)

This engine is actually known for being really easy on oil. Toyota recommends using 5w30 viscosity so it’s best to stick with that. Synthetic oil isn’t required but many V8 4runner owners prefer to use it.

My 4runner sees a lot of short trips and not a whole lot of overall mileage (driving is spread out over 3 vehicles). Because of that, it’s more important to me to stick with a shorter oil change interval. I’d rather focus on having fresh, clean oil often than worry about fancy additives that will allow me to stretch it longer.

There’s isn’t any downside to running synthetic oil other than the higher price so feel free to make the switch if you feel it’s worth it. Many 4runner owners happily run Mobil 1 5w30.

Burning or leaking oil are not common issues with this engine. On top of that, these Toyotas are built tough. A lot of forum users have sent their oil out for analysis and have been surprised by how fresh it still was after an entire service interval.

There’s no need to overthink your choice of oil too much – I simply go with whatever brand of regular 5w30 happens to be on sale at the time. The 2UZ is not picky about oil so as long as you keep it clean, you shouldn’t have any problems.

V8 4runner oil change interval:

Between 3,000 – 5,000 miles with conventional oil depending on usage. If the vehicle is being driven for a lot of short trips, it’s best to change the oil more often to prevent sludge buildup. Using synthetic oil will allow you to extend the interval by quite a bit.

Best oil filter for the 4.7L V8 (2UZ)

I recommend using a genuine Toyota oil filter (YZZD3). I’ve used generic ones from the parts store when I’ve been in a bind and haven’t been able to get to the dealership but in my experience they’ve been a smaller size than the Toyota one.

Again, it’s not exactly a life or death situation with this engine but using Toyota filters is a safe bet. You’ll probably want to get a new washer for the drain plug from them as well.

Best gear oil for 4th gen 4runner differentials and transfer case

Toyota recommends using GL-5 75w-90 oil for both the transfer case and differentials. The Toyota branded gear oil is expensive though and in some cases, hard to find.

It’s fine to use 75w-90 synthetic gear oil from other brands. Unlike the motor oil, I stick with synthetic in this case.

4th gen 4runner differential and transfer case oil change interval

The service interval for differential and transfer case fluid is much longer than your engine oil. Toyota recommends changing them every 32,000 kms (19,883 miles). Many 4runner owners will extend that by quite a bit, sometimes even to 60,000+ without any issues.

Tools needed to change engine oil:

• 12mm socket for skid plate bolts
• 14mm socket for oil drain plug
• oil filter wrench (if it’s on too tight)

Tools needed to change differential and transfer case fluid:

• 24mm socket for transfer case and rear diff fill/drain bolts
• 12mm socket for transmission skid plate bolts
• 10mm Hex/Allen key

How to change the oil on a V8 4runner

Remove the front skid plate

The only thing that differs when changing the oil on a V8 4runner vs a V6 is the need to remove the front skid plate. This needs to be done in order to fully access the oil filter.

Some people have found ways around this by reaching the filter from the top or modifying the skid plate. In all honesty, removing it isn’t difficult at all. It’s held on by 4 12mm bolts.

Be careful here – the skid plate bolts love to snap off.

The transmission skid plate will also need to be removed if you’re changing the oil in the front differential so you might as well remove both at the same time.

Drain the engine oil

Find the 14mm drain plug for the engine (not the transmission!) and drain the oil into a pan. Allowing the engine to warm up a bit will speed up the amount of time it takes for the oil to drain out. Be careful not to burn yourself though.

Removing the oil cap in the engine bay will also allow the oil to drain quicker.

Clean and tighten the drain plug

Once the oil has drained out, clean up the drain plug and if you have one, replace the washer on it (#90430-12031). Go ahead and tighten the plug. If you’re a stickler for torque specs, you can torque the plug to 29 ft/lbs.

Remove the oil filter

With nearly all of the oil out of the engine, it’s time to remove the filter. Get your drain pan handy though because the filter will still be full of oil. You should be able to reach in and remove this by hand but if it’s been installed too tight, you might need to use an oil filter wrench to get it off.

Install the new oil filter

Now you can put the new oil filter on. Make sure to add a light layer of oil to the seal (dabbing your finger in the oil you drained out and running it around the seal is fine). Thread the filter on until the seal makes contact with the housing – then give it another 3/4 turn. This should be snug but not super tight.

Fill the engine with oil

You might want to use a funnel here to minimize any spilling in the engine bay. Fill it with at least 6 liters of oil. Once it’s full, start the engine up for a few seconds and shut it back off. Check the dipstick for an accurate reading of how much oil you have in the engine and whether or not you need to add more.

Reinstall the skid plate

If you’re just doing the engine oil change, you can bolt the skid plate back up. It might be a good idea to put some grease or anti-seize on the bolts to avoid any problems with them in the future. This won’t be the last time you change the oil!

How to change the front differential fluid on a 4th gen 4runner

Remove the transmission skid plate

If you haven’t already, remove the 2nd skid plate. This will allow access to the front differential. Again, be careful – these bolts like to snap off too.

Loosen the fill bolt

Both the fill and drain bolts are located on the driver’s side of the front differential.

When doing a job like this, you always want to loosen the fill bolt first. The reason for that is you don’t want to drain all of the oil out and find out you can’t get any back in because the fill bolt is stuck. This requires a 10mm Hex key.

Drain the differential fluid

Loosen the 10mm drain bolt and drain the oil into a pan. Be very careful when cracking both the fill and drain bolts loose. I don’t know why Toyota chose to go with hex bolts for these but they’re very easy to round out when they’re stuck.

A little penetrating oil ahead of time is a good idea on all of the fill and drain bolts, not just the Hex ones.

Inspect and clean the drain and fill bolts

Clean up the bolts before putting them back in. If you’ve got new washers for the bolts, don’t forget to switch them over (fill: #12157-10010, drain: #90430-24003).

Take note of any metal shavings on the magnets and also take a look at the condition of the oil you drained from the differential. Finding a lot of metal and grime can be an indicator of a bigger problem.

Fill the differential with gear oil

Tighten up the drain bolt (you can torque it to 20 ft-lbs if you want to). Now you can begin pumping fresh oil into the fill hole. Keep adding oil until it begins to drip out of the fill hole – that’s how you know it’s full.

Tighten the fill bolt

Now you can tighten up the fill bolt and wipe off any oil on the outside. Your front differential fluid change is complete!

Reinstall both skid plates

If you’ve already changed the engine oil and front differential, you can feel free to reinstall the skid plates. You can access everything else with them in place.

How to change the transfer case fluid on a 4th gen 4runner

Crack the fill bolt loose

Just like with the differentials, you want to make sure you’ll be able to get new fluid in before you drain the old stuff out. Both the fill and drain bolts are located on the rear side of the transfer case.

Drain the transfer case fluid

Remove the 24mm drain bolt and drain all the oil into your pan. Take note of any metal shavings on the magnet and/or in the old oil.

Inspect and clean the fill and drain bolts

Clean both bolts up and replace the washers before you reinstall them (#90430-18008). You can torque both of these to 27 ft-lbs if you want to.

Fill the transfer case with gear oil

Now it’s time to pump your new fluid into the transfer case. Keep adding fluid until it begins to drip out of the fill hole.

Tighten the fill bolt

All that’s left to do is to tighten up the fill plug and you’re all done. It’s a good idea to cycle the 4×4 after changing the fluid. You should already be doing this once per month to keep the actuator moving freely.

How to change the rear differential fluid on a 4th gen 4runner

Loosen the fill bolt

No surprises here – the process for the rear differential is the same as the front and transfer case. Crack the fill bolt loose to avoid any problems.

Drain the differential fluid

The 24mm drain bolt is located on the bottom of the differential. Pop this out and drain the fluid into your pan. Once again, check out the magnet and old oil for any shavings. The rear differential fluid will likely be the dirtiest of the 3.

Inspect and clean the fill and drain bolts

Clean up the bolts and replace the washers if you have them (#12157-10010). You can torque these to 36 ft-lbs if you want to.

Fill the differential with gear oil

Now you can pump your new fluid up into the differential. It’ll begin leaking out of the fill hole when it’s full.

Tighten the fill bolt

Once you tighten up the fill bolt, your service is complete.

Conclusion

Changing the differential and transfer case fluid might be messy (and you’ll be dealing with the smell of gear oil for quite some time) but it’s a fairly straight forward process. Take your time and be careful not to strip any of the drain or fill bolts.

Knowing that all of your fluids are fresh will give you peace of mind and the confidence to go out and rack thousands more miles on your 4runner. You’ll also know that it was done right and all the drain bolts are tight which is more than can be said for a lot of the quick oil change shops out there!