How to Change a 4th Gen 4Runner’s Rear Differential Fluid 

Nicely done!! Way to keep the 4th gen alive.

Coming out soon!!

I’ve considered it, but with it being a sealed unit I’ve held off for now!

Thanks so much!

Short answer: Because it’s gear oil haha. Long answer: If you go to the service desk at Toyota and ask for gear oil they will hand you Mobil 1 synthetic 75w90 9 times of out ten because it’s significantly cheaper and practically the same thing. The reason 75w85 is “recommended” is due to the very, minimal, mostly insignificant viscous drag coefficient (< 1%) that allowed for slightly better scores during testing and related. In reality 75w90 does the same thing, and the added thickness is better for the ring and pinion. I personally have found redline the best gear oil and runs considerably smoother than alternatives with a better longevity. The synthetic 75w90 is just as thin as a 75w85 and gives a little more cushion as well. The best quality stuff I’ve found!

@@looseaxles well then dude I guess you are "Wild e Coyote super genius" in the flesh. Thanks for your answer though I do believe the engineer who designed the axle and required the 75w85 oil might just know a little more than you.

@@dennisb.1996haha you’ll find most Toyota mechanics and enthusiasts run the same weight oil, as do the Toyota shops themselves. No need to be condescending - it’s a very common practice lol.

@@looseaxles so how is speaking the truth condescending? I guess after running non toyota recomended gear oil viscosity is how you got your handel then "looseaxles." You guys trying to defend undefedable positions slay me!

My 05 v8 recommends both front and rear 90 or 80-90 cold. 75-90 in transfer case… as long as you don’t go higher than 90 you’ll be fine.

I’m not too sure which one would be best to be honest. This is a great question. I would probably chose whatever has the most similar compound to the Toyota OEM spec.

With some to spare!

I don’t recall what I said, but being Canadian I can only assume I was wrong! Litres litres litres!

No worries I thought I might be crazy. Very glad I came across this video just got a 03 4runner trying to stay on top of maintenance, great stuff!

Congrats on the purchase and welcome to the 4th gen club!

@@looseaxles haha don't worry we have to look up conversions to our stupid measurements all the time! #metric-is-superior

Thanks!! I’d definitely recommend getting the Toyota washers as a leaky diff is never fun!

Hey Doug! I bought it separately. I have the link in the description! Super handy.

Exact same process! Thanks for stopping by!

The 90 weight was significantly easier to find and I love the quality of redline products!

I went to the dealership the other day to ask them what they use in the rear diff. They said 75w-85. It’s not readily available so I asked them if they had containers of -85. They did. For $112 a can. I said no thanks and went to auto zone to pick up royal purple 75w-90

You can now do it for half price and have the tools for next time!