2008 T4R Ltd. 4.7L AWD Differential Fluid Change

[LEM]

I am just over 30,000 miles on my 2008 4Runner and I want to change out the factory lubricant in the front and rear differentials and the transfer case. I am considering Royal Purple and Amsoil as the replacement fluid.

I have read that some folks have used 75W-90 on all three, but according to the owners manual 75W-90 is used only in the transfer case and 80W-90 is used in the differentials.





Questions: Which fluid manufacturer have you used with great success? What weight oil did you use? What were the results in performance?

Thanks.

[Airjer_]

the lighter oil will only make a difference when the whether dips below freezing. Otherwise once the fluid warms up they will both be 90 weight oils.

[Brian R.]

I use 80W-90 in all gear applications except when there is an actuator involved (such as an ADD system), and then I use 75W-90 so that the actuator can do its job easier when it's cold. I used Mobil 1. I consider both of the ones you mentioned overpriced. I doubt that you will see any difference in performance no matter what gear oil brand you use. I just used a synthetic to increase the drain interval.

[LEM]

The job went pretty well; the only surprise was how quickly the oil came out of the front differential. I didn't have my drain pan lined up quite right and dumped about a pint of oil onto the driveway, good thing it's asphalt. I leaernd my lesson and didn't repeat the mistake on the others.

It seemed that the front differential oil was the most discolored of the three; it had a grayish tint to it and was a little more cloudy than the transfer case or rear differential fluid. Both the front and rear drain plugs had a layer of metal wear particles on them, but nothing out of the ordinary.

I filled all three with Amsoil 75W-90 for $12.75/quart. Royal Purple would have cost $19.95/quart. I could have gotten Mobil 1 for about $11/quart, but I've been wanting to try Amsoil and I've read a lot of good things about it...we'll see.

I did not drop the spare tire to work on the rear end, and really didn't need to. I drove the front wheels up on ramps and jacked the back-end up onto jackstands so that the vehicle was level - I even used a bubble level to check it. This gave me easy access to all the undercarriage.

I purchased a Wilmar fluid transfer pump from O'Reilly's and the necessary 24-mm socket and 10-mm hex bit from Sears. I also go the crush washers from Toyota locally. I borrowed a 1/2" torque wrench from work. These tools and supplies made the job go much more easily and quickly; about 1 hour total, not including clean-up.

I seemed to have already noticed a slight improvement in gas mileage, maybe 1 to 1.5 mpg on a combination of winding mountain roads and straight flat interstate. Hopefully this will prove to be the case.

Overall, a pretty easy job...if you have the right tools.

Oh-I did get a couple cans of Krylon flat black to paint the rear end; somehow it had gotten a few minor scratches on it already that had rusted. I cleaned it up and painted it. It looks great!

Thanks for the help and advice.