Engine Oil : Whatever cheap full synthetic I can find. I replace it every 3-4k miles. I switched from dino to full synth about 3 oil changes ago and no problems.
Transmission Fluid: Valvoline Full Synth Max Life Red bottle - drain and fill every 10-15k miles
Gear Oil : O'Reilly brand 75w90

So far so good. No issues.

Just change it regularly, and you wont have any issues.

I'm probably going to get blown out of the water on this one but it's an Automatic. I checked the transmission fluid and it is nowhere near to any shade of red.

I want to say thank you for all the replies. I have more guidance than I started with so I am going to do the engine, transmission and rear diff this weekend.

@Zorrota , I am doing the intermediate step in the meantime because I have a trip coming up and money is tight. When the trip is over then I will do a full fluid exchange.

@thegipper , I was told beforehand to check the ball joints, I have moved that item to the front of the list. Could you link the "Amsoil severe duty"? It would be greatly appreciated.

Amsoil, at least by two reps, recommended the severe duty 75w-110. I instead had some Mobil 1 75w-90 lying around and used it. I think this is the weight @thegipper was recommending.

If the ATF fluid is dark, I would at least start with a couple of drain and fills. Measure on the dipstick with the ATF at normal temp, run through the gears with the foot on the brake and then check on a flat surface. I have had great luck with Castrol Import ATF.

Any engine oil will do, I use Valvoline Maxlife 10w-30 myself.

The more and more I think about it I might just get it over with and do the fluid exchange with Amsoil for the transmission.

I can't remember what weight I used OP but you can use the Amsoil website and it should list which product our trucks are supposed to use.

Transmissions are super sensitive when they have high miles. Have to be real careful with fluid exchanges....sometimes it’s best to leave well enough alone.

Thank you for the advice Brodozer.

I called a local shop and they mentioned the same thing. They said that if I wanted the fluid to be changed and the current fluid is too dark I would have to bring it in so they can drop the pan, replace the filter, reseal the pan and exchange the fluid completely.

I take my own advice....my newly acquired ‘98 SR5 2wd has 205,000 miles on it. I just changed all the fluids, except transmission (it looks good, smells ok, is red (enough) and shifts well).

I put 75w90 Valvoline synthetic in the rear diff. 2.6 quarts. Valvoline Maxlife high mileage 5w30 in the crankcase. 5.5 quarts. Swapped in Maxlife ATF in the power steering pump. And new DOT4 brake fluid.

About using a gear oil for rear diff: if you use 85w140 will it reduce your mpg vs using 75w90?
Here in Mozambique, the guy who is purported to be THE diff guy, says to use 85w140 in our vehicles. However, the guys who rebuilt my engine in SA and have done some other services and repairs for me, won't admit you can use anything different than Toyo spec for the vehicle (I'm sure it's liability issues). And I have one guy who manages a well-known 4x4 modding shop who says to use the 75w90.

So when I heard the Moz guy said to use the 85w140 I thought to look up in the forum. And also had a conversation with a friend and he mentioned the mpg issue. So I'm putting it out here.

Thanks much for thoughts.
David

I use 75-90 synthetic in the front diff and synthetic 75-140 in the rear diff.


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Do you know if there's any drop-off in mpg using that 75w140 in the rear end?
Thanks much.

I run the wallymart 75-140 full synth everywhere.
No diff in mpgs....Enjoy the Runner.

I didn’t notice any. However, I drive a S Series Saturn that gets 40mpg in the dead of winter as my DD. I get 17 to 20mpg on the 4Runner in my normal driving.


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Here's what I'm using in my rigs now. I use to run conventional oils but now I'm running full synthetic across the board.

*Castrol EDGE Extended Performance 5W-30 Advanced Full Synthetic Motor Oil
Amazon.com: Castrol 03087 EDGE Extended Performance 5W-30 Advanced Full Synthetic Motor Oil, 5 Quart: Automotive

*Valvoline Max Life Full Synthetic ATF (For transmission and power steering)
Amazon.com: Valvoline 773775-3PK Auto Trans Fluid, 3. gallons, 3 Pack: Automotive

*Red Line 75W90 GL-5 Full Synthetic Gear Oil (For transfer case and both differentials) Amazon.com: Red Line 57905 75W90 GL-5 Gear Oil - 1 Gallon: Automotive

I was thinking of going to valvoline max life full synthetic atf.. How do you like it?

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