Differential Fluid Change DIY Guide (Front & Rear Diff) - for 2025+ 4Runner 6th gen

[FloridaPhotog]

Very detailed procedure, thank you. I wonder what a dealer would charge to change front and rear? I am getting to the point of not wanting to do my own vehicle maintenance

I asked my dealership here in Florida yesterday. It was $199 per differential. They also said they use 75w90 , so we know it isn’t Toyota branded.

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[Gerardo]

This is so helpful, thank you so much @Henry!

 

[jackburton]

great write up!

It's strange that Amsoil's website doesn't list any fluids for the Transfer Case and Differential.

https://www.amsoil.com/lookup/auto-...nner/2-4l-4-cyl-engine-code-t24a-fts-2-turbo/

 

[MStarmer]

Anyone ever check the levels when you first get the vehicle? This is my 4th 4Runner and I always make it a habit to double check the diff's and transfer case. Just got done and the rear was pretty light I think I put about a 1/3rd of a quart in, front was a little better. Transfer case was almost up the top but still took a pretty good pump to get it to the fill plug. I used Redline 75/85 for the diffs and MT-LV for the transfer case. I'll double check the trans fluid probably on the weekend if my OBDII reader will pick up the temp. I only use factory WS for that one. Not that I don't trust Toyota, but I don't trust anyone.

 

[kekecarioca]

I did my rear Diff oil change last week @ 30K and to be honest the oil still looked "pretty" good. Of course it had metal sparkles and sludge on the plug but it still had quite a nice gold tone to it.

Note I have a TH that holds an extra quart in there and did minimal towing and hard off-roading a few times.

 

[MikeD]

Did the front and rear differential fluid change last weekend at 18,032 miles. Just a small bit of towing in that milage but a healthy amount of off-roading (~12 outings - mostly blue trails and one black).
The rear was surprisingly clean (see photo of it draining out). Decent amount of "iron filings" on the magnet but no metal chunks like the Car Care Nut had on his Tundra.
I needed a 7th bottle to fill the rear diff. It took ~6.3 quarts. Some of that extra was spillage as I figured out how to use the pump I got which was too big for the Redline bottle opening.
Front probably didn't require a change since I had the TRD Lift Kit installed less than 1500 miles ago and it is supposed to include a drain of the front diff as part of installing the new front axels but I had the truck on jack stands/skid plates off; and when I checked the front diff fill spot the fluid was a different color (greyish brown?) than what came out of the rear (and the Redline 75W85 that I put in) so I went ahead and drained/filled it.
Surprisingly CLEAN rear diff fluid

Rear diff fill and drain plugs.

Awkward, ill fitting pump

 

[SC4Runner]

Did the front and rear differential fluid change last weekend at 18,032 miles. Just a small bit of towing in that milage but a healthy amount of off-roading (~12 outings - mostly blue trails and one black).
The rear was surprisingly clean (see photo of it draining out). Decent amount of "iron filings" on the magnet but no metal chunks like the Car Care Nut had on his Tundra.
I needed a 7th bottle to fill the rear diff. It took ~6.3 quarts. Some of that extra was spillage as I figured out how to use the pump I got which was too big for the Redline bottle opening.
Front probably didn't require a change since I had the TRD Lift Kit installed less than 1500 miles ago and it is supposed to include a drain of the front diff as part of installing the new front axels but I had the truck on jack stands/skid plates off; and when I checked the front diff fill spot the fluid was a different color (greyish brown?) than what came out of the rear (and the Redline 75W85 that I put in) so I went ahead and drained/filled it.
Surprisingly CLEAN rear diff fluid

Rear diff fill and drain plugs.

Awkward, ill fitting pump

I did front differential and transmission along with an oil change at 20k and plan the rear and transfer case next weekend. I was surprised how clean all that looked as well! My plan is to do this every 20k as I’ve heard a number of 4Runner owners claim you won’t ever have any problems if you do this. Glad I somehow ended up with an extra case of gear oil though if the rear took over 6 quarts! I‘ve heard good things about the Red Line but ended up going with Triax.

On another note, how often are you planning to change your spark plugs? I am planning every 25k to prevent any engine knock.

 

[MikeD]

On another note, how often are you planning to change your spark plugs? I am planning every 25k to prevent any engine knock.

Interesting - spark plugs are not on my current short list. Will probably replace at 80K per maint. schedule unless engine starts to run rough. Maybe I’ll take one out and get some photographic evidence of current condition and check again at 30k and 45K miles to see changes.

 

[SC4Runner]

Interesting - spark plugs are not on my current short list. Will probably replace at 80K per maint. schedule unless engine starts to run rough. Maybe I’ll take one out and get some photographic evidence of current condition and check again at 30k and 45K miles to see changes.

In one of the LC forums, I found they are recommending 40k per the manual with some noting they are changing plugs at the 25k-30k mark. I’m running some performance mods - intercooler, charge pipes, downpipe and a tune with more on the way. Given all that, I’m shooting for 25k. If they don’t look too bad, I’ll stretch to 30k and pull one about every 10k or so as you have suggested To keep an eye on it. Engine knock on these can cause some damage!

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